77 |
78 | 
79 |
80 |
81 |
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/SECURITY.md:
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1 | # Security policy
2 |
3 | ## Reporting a vulnerability
4 |
5 | If you have found a possible vulnerability, please email `security at astral dot sh`.
6 |
7 | ## Bug bounties
8 |
9 | While we sincerely appreciate and encourage reports of suspected security problems, please note that
10 | Astral does not currently run any bug bounty programs.
11 |
12 | ## Vulnerability disclosures
13 |
14 | Critical vulnerabilities will be disclosed via GitHub's
15 | [security advisory](https://github.com/astral-sh/ty/security) system.
16 |
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/_typos.toml:
--------------------------------------------------------------------------------
1 | [files]
2 | extend-exclude = []
3 |
4 | [default.extend-words]
5 |
6 | [default]
7 | extend-ignore-re = [
8 | # Line ignore with trailing "spellchecker:disable-line"
9 | "(?Rm)^.*#\\s*spellchecker:disable-line$",
10 | "LICENSEs",
11 | ]
12 |
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/dist-workspace.toml:
--------------------------------------------------------------------------------
1 | [workspace]
2 | members = ["cargo:./ruff"]
3 | packages = ["ty"]
4 | version = "0.0.1-alpha.7"
5 |
6 | # Config for 'dist'
7 | [dist]
8 | # The preferred dist version to use in CI (Cargo.toml SemVer syntax)
9 | cargo-dist-version = "0.28.5-prerelease.3"
10 | # Whether to consider the binaries in a package for distribution (defaults true)
11 | dist = false
12 | # CI backends to support
13 | ci = "github"
14 | # The installers to generate for each app
15 | installers = ["shell", "powershell"]
16 | # The archive format to use for windows builds (defaults .zip)
17 | windows-archive = ".zip"
18 | # The archive format to use for non-windows builds (defaults .tar.xz)
19 | unix-archive = ".tar.gz"
20 | # Target platforms to build apps for (Rust target-triple syntax)
21 | targets = [
22 | "aarch64-apple-darwin",
23 | "aarch64-unknown-linux-gnu",
24 | "aarch64-unknown-linux-musl",
25 | "aarch64-pc-windows-msvc",
26 | "arm-unknown-linux-musleabihf",
27 | "armv7-unknown-linux-gnueabihf",
28 | "armv7-unknown-linux-musleabihf",
29 | "x86_64-apple-darwin",
30 | "powerpc64-unknown-linux-gnu",
31 | "powerpc64le-unknown-linux-gnu",
32 | "s390x-unknown-linux-gnu",
33 | "x86_64-unknown-linux-gnu",
34 | "x86_64-unknown-linux-musl",
35 | "x86_64-pc-windows-msvc",
36 | "i686-unknown-linux-gnu",
37 | "i686-unknown-linux-musl",
38 | "i686-pc-windows-msvc",
39 | ]
40 | # Whether to auto-include files like READMEs, LICENSEs, and CHANGELOGs (default true)
41 | auto-includes = false
42 | # Whether dist should create a Github Release or use an existing draft
43 | create-release = true
44 | # Which actions to run on pull requests
45 | pr-run-mode = "plan"
46 | # Whether to publish prereleases to package managers
47 | publish-prereleases = true
48 | # Whether CI should trigger releases with dispatches instead of tag pushes
49 | dispatch-releases = true
50 | # Which phase dist should use to create the GitHub release
51 | github-release = "announce"
52 | # Whether CI should include auto-generated code to build local artifacts
53 | build-local-artifacts = false
54 | # Local artifacts jobs to run in CI
55 | local-artifacts-jobs = ["./build-binaries", "./build-docker"]
56 | # Publish jobs to run in CI
57 | publish-jobs = ["./publish-pypi"]
58 | # Post-announce jobs to run in CI
59 | post-announce-jobs = []
60 | # Custom permissions for GitHub Jobs
61 | github-custom-job-permissions = { "build-docker" = { packages = "write", contents = "read" } }
62 | # Whether to install an updater program
63 | install-updater = false
64 | # Path that installers should place binaries in
65 | install-path = ["$XDG_BIN_HOME/", "$XDG_DATA_HOME/../bin", "~/.local/bin"]
66 |
67 | [dist.github-custom-runners]
68 | global = "depot-ubuntu-latest-4"
69 |
70 | [dist.github-action-commits]
71 | "actions/checkout" = "85e6279cec87321a52edac9c87bce653a07cf6c2" # v4
72 | "actions/upload-artifact" = "6027e3dd177782cd8ab9af838c04fd81a07f1d47" # v4.6.2
73 | "actions/download-artifact" = "d3f86a106a0bac45b974a628896c90dbdf5c8093" # v4.3.0
74 | "actions/attest-build-provenance" = "c074443f1aee8d4aeeae555aebba3282517141b2" #v2.2.3
75 |
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/docs/README.md:
--------------------------------------------------------------------------------
1 | # ty
2 |
3 | **[Installation](#installation)** |
4 | **[Usage](#usage)** |
5 | **[Module discovery](#module-discovery)** |
6 | **[Editor integration](#editor-integration)** |
7 | **[Rules](#rules)** |
8 | **[Suppressions](#suppressions)** |
9 | **[Exit codes](#exit-codes)** |
10 | **[Reference](#reference)**
11 |
12 | ## Getting started
13 |
14 | For a quick guide on getting started, see the top-level [README](../README.md#getting-started).
15 |
16 | ## Installation
17 |
18 | ### Adding ty to your project
19 |
20 | Use [uv](https://github.com/astral-sh/uv) (or your project manager of choice) to add ty as a
21 | development dependency:
22 |
23 | ```shell
24 | uv add --dev ty
25 | ```
26 |
27 | Adding ty as a dependency ensures that all developers on the project are using the same version of
28 | ty.
29 |
30 | Then, use `uv run` to invoke ty:
31 |
32 | ```shell
33 | uv run ty
34 | ```
35 |
36 | ### Installing globally
37 |
38 | Install ty globally with uv:
39 |
40 | ```shell
41 | uv tool install ty@latest
42 | ```
43 |
44 | Or, pipx:
45 |
46 | ```shell
47 | pipx install ty
48 | ```
49 |
50 | ### Installing with pip
51 |
52 | Install ty into your current Python environment with pip:
53 |
54 | ```shell
55 | pip install ty
56 | ```
57 |
58 | ### Usage
59 |
60 | Run [`ty check`](./reference/cli.md#ty-check), in your project's top-level directory,
61 | to check the project for type errors using ty's default configuration.
62 |
63 | If this provokes a cascade of errors, and you are using the standard library `venv` module
64 | to provide your virtual environment, add the venv directory to your `.gitignore`
65 | or `.ignore` file and then retry.
66 |
67 | ## Module discovery
68 |
69 | ### First-party modules
70 |
71 | First-party modules are Python files that are part of your project source code.
72 |
73 | By default, ty searches for first-party modules in the project's root directory or the `src`
74 | directory, if present.
75 |
76 | If your project uses a different layout, configure the project's
77 | [`src.root`](./reference/configuration.md#root) in your `pyproject.toml` or `ty.toml`. For example,
78 | if your project's code is in an `app/` directory:
79 |
80 | ```text
81 | example-pkg
82 | ├── README.md
83 | ├── pyproject.toml
84 | └── app
85 | └── example_pkg
86 | └── __init__.py
87 | ```
88 |
89 | then set [`src.root`](./reference/configuration.md#root) in your `pyproject.toml` to `./app`:
90 |
91 | ```toml
92 | [tool.ty.src]
93 | root = "./app"
94 | ```
95 |
96 | ### Third-party modules
97 |
98 | Third-party modules are Python packages that are not part of your project or the standard library.
99 | These are usually declared as dependencies in a `pyproject.toml` or `requirements.txt` file
100 | and installed using a package manager like uv or pip. Examples of popular third-party
101 | modules are `requests`, `numpy` and `django`.
102 |
103 | ty searches for third-party modules in the configured [Python environment](#python-environment).
104 |
105 | ### Python environment
106 |
107 | The Python environment is used for discovery of third-party modules.
108 |
109 | By default, ty will attempt to discover a virtual environment.
110 |
111 | First, ty checks for an active virtual environment using the `VIRTUAL_ENV` environment variable. If
112 | not set, ty will search for a `.venv` directory in the project root or working directory. ty only
113 | supports discovery of virtual environments at this time.
114 |
115 | > [!NOTE]
116 | >
117 | > When using project management tools, such as uv or Poetry, the `run` command usually automatically
118 | > activates the virtual environment and will be detected by ty.
119 |
120 | The Python environment may be explicitly configured using the
121 | [`environment.python`](./reference/configuration.md#python) setting or
122 | [`--python`](./reference/cli.md#ty-check--python) flag.
123 |
124 | When setting the environment explicitly, non-virtual environments can be provided.
125 |
126 | ## Python version
127 |
128 | The Python version affects allowed syntax, type definitions of the standard library, and type
129 | definitions of first- and third-party modules that are conditional on the Python version.
130 |
131 | For example, Python 3.10 introduced support for `match` statements and added the
132 | `sys.stdlib_module_names` symbol to the standard library. Syntactic features always
133 | need to be available in the lowest supported Python version, but symbols may be used
134 | in a `sys.version_info` conditional branch:
135 |
136 | ```python
137 | import sys
138 |
139 | # `invalid-syntax` error if `python-version` is set to 3.9 or lower:
140 | match "echo hello".split():
141 | case ["echo", message]:
142 | print(message)
143 | case _:
144 | print("unknown command")
145 |
146 | # `unresolved-attribute` error if `python-version` is set to 3.9 or lower:
147 | print(sys.stdlib_module_names)
148 |
149 | if sys.version_info >= (3, 10):
150 | # ok, because the usage is guarded by a version check:
151 | print(sys.stdlib_module_names)
152 | ```
153 |
154 | By default, the lower bound of the project's [`requires-python`](<(https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#python-requires)>) field (from the `pyproject.toml`) is
155 | used as the target Python version, ensuring that features and symbols only available in newer Python
156 | versions are not used.
157 |
158 | If the `requires-python` field is not available, the latest stable version supported by ty is used,
159 | which is currently 3.13.
160 |
161 | ty will not infer the Python version from the Python environment at this time.
162 |
163 | The Python version may be explicitly specified using the
164 | [`python-version`](./reference/configuration.md#python-version) setting or the
165 | [`--python-version`](./reference/cli.md#ty-check--python-version) flag.
166 |
167 | ## Excluding files
168 |
169 | By default, ty ignores files listed in an `.ignore` or `.gitignore` file.
170 |
171 | To disable this functionality, set [`respect-ignore-files`](./reference/configuration.md#respect-ignore-files) to `false`.
172 |
173 | You may also explicitly pass the paths that ty should check, e.g.:
174 |
175 | ```shell
176 | ty check src scripts/benchmark.py
177 | ```
178 |
179 | We plan on adding dedicated options for including and excluding files in future releases.
180 |
181 | ## Editor integration
182 |
183 | ty can be integrated with various editors to provide a seamless development experience.
184 |
185 | ### VS Code
186 |
187 | The Astral team maintains an official VS Code extension.
188 |
189 | Install the [ty extension](https://marketplace.visualstudio.com/items?itemName=astral-sh.ty) from the VS Code Marketplace.
190 |
191 | See the extension's [README](https://github.com/astral-sh/ty-vscode) for more details on usage.
192 |
193 | ### Other editors
194 |
195 | ty can be used with any editor that supports the [language server
196 | protocol](https://microsoft.github.io/language-server-protocol/).
197 |
198 | To start the language server, use the `server` subcommand:
199 |
200 | ```shell
201 | ty server
202 | ```
203 |
204 | Refer to your editor's documentation to learn how to connect to an LSP server.
205 |
206 | See the [editor settings](./reference/editor-settings.md) for more details on configuring the language
207 | server.
208 |
209 | #### Neovim
210 |
211 | For Neovim 0.10 or earlier (with [`nvim-lspconfig`](https://github.com/neovim/nvim-lspconfig)):
212 |
213 | ```lua
214 | require('lspconfig').ty.setup({
215 | init_options = {
216 | settings = {
217 | -- ty language server settings go here
218 | }
219 | }
220 | })
221 | ```
222 |
223 | For Neovim 0.11+ (with [`vim.lsp.config`](
79 |
80 | Usage
10 | 11 | ``` 12 | tyCommands
16 | 17 |ty checkCheck a project for type errors
18 | ty serverStart the language server
19 | ty versionDisplay ty's version
20 | ty helpPrint this message or the help of the given subcommand(s)
21 |
Usage
28 | 29 | ``` 30 | ty check [OPTIONS] [PATH]... 31 | ``` 32 | 33 |Arguments
34 | 35 |PATHSList of files or directories to check [default: the project root]
36 |
Options
39 | 40 |--colorwhenControl when colored output is used
41 |Possible values:
42 |-
43 |
auto: Display colors if the output goes to an interactive terminal
44 | always: Always display colors
45 | never: Never display colors
46 |
--config,-cconfig-optionA TOML
48 |<KEY> = <VALUE>pair (such as you might find in aty.tomlconfiguration file) 47 | overriding a specific configuration option.Overrides of individual settings using this option always take precedence 49 | over all configuration files.
50 |--errorruleTreat the given rule as having severity 'error'. Can be specified multiple times.
51 |--error-on-warningUse exit code 1 if there are any warning-level diagnostics
52 |--exit-zeroAlways use exit code 0, even when there are error-level diagnostics
53 |--extra-search-pathpathAdditional path to use as a module-resolution source (can be passed multiple times)
54 |--help,-hPrint help (see a summary with '-h')
55 |--ignoreruleDisables the rule. Can be specified multiple times.
56 |--output-formatoutput-formatThe format to use for printing diagnostic messages
57 |Possible values:
58 |-
59 |
full: Print diagnostics verbosely, with context and helpful hints [default]
60 | concise: Print diagnostics concisely, one per line
61 |
--projectprojectRun the command within the given project directory.
62 |All
63 |pyproject.tomlfiles will be discovered by walking up the directory tree from the given project directory, as will the project's virtual environment (.venv) unless thevenv-pathoption is set.Other command-line arguments (such as relative paths) will be resolved relative to the current working directory.
64 |--pythonpathPath to the Python environment.
65 |ty uses the Python environment to resolve type information and third-party dependencies.
66 |If not specified, ty will attempt to infer it from the
67 |VIRTUAL_ENVenvironment variable or discover a.venvdirectory in the project root or working directory.If a path to a Python interpreter is provided, e.g.,
68 |.venv/bin/python3, ty will attempt to find an environment two directories up from the interpreter's path, e.g.,.venv. At this time, ty does not invoke the interpreter to determine the location of the environment. This means that ty will not resolve dynamic executables such as a shim.ty will search in the resolved environments's
69 |site-packagesdirectories for type information and third-party imports.--python-platform,--platformplatformTarget platform to assume when resolving types.
70 |This is used to specialize the type of
71 |sys.platformand will affect the visibility of platform-specific functions and attributes. If the value is set toall, no assumptions are made about the target platform. If unspecified, the current system's platform will be used.--python-version,--target-versionversionPython version to assume when resolving types.
72 |The Python version affects allowed syntax, type definitions of the standard library, and type definitions of first- and third-party modules that are conditional on the Python version.
73 |By default, the Python version is inferred as the lower bound of the project's
74 |requires-pythonfield from thepyproject.toml, if available. Otherwise, the latest stable version supported by ty is used, which is currently 3.13.ty will not infer the Python version from the Python environment at this time.
75 |Possible values:
76 |-
77 |
3.7
78 | 3.8
79 | 3.9
80 | 3.10
81 | 3.11
82 | 3.12
83 | 3.13
84 |
--respect-ignore-filesRespect file exclusions via
85 |.gitignoreand other standard ignore files. Use--no-respect-gitignoreto disable--typeshed,--custom-typeshed-dirpathCustom directory to use for stdlib typeshed stubs
86 |--verbose,-vUse verbose output (or
87 |-vvand-vvvfor more verbose output)--warnruleTreat the given rule as having severity 'warn'. Can be specified multiple times.
88 |--watch,-WWatch files for changes and recheck files related to the changed files
89 |
Usage
96 | 97 | ``` 98 | ty server 99 | ``` 100 | 101 |Options
102 | 103 |--help,-hPrint help
104 |
Usage
111 | 112 | ``` 113 | ty version 114 | ``` 115 | 116 |Options
117 | 118 |--help,-hPrint help
119 |
Usage
126 | 127 | ``` 128 | ty generate-shell-completionArguments
132 | 133 | 134 | 135 |Options
136 | 137 |--help,-hPrint help
138 |
Usage
145 | 146 | ``` 147 | ty help [COMMAND] 148 | ``` 149 | 150 | -------------------------------------------------------------------------------- /docs/reference/configuration.md: -------------------------------------------------------------------------------- 1 | 2 | 3 | # Configuration 4 | #### `rules` 5 | 6 | Configures the enabled rules and their severity. 7 | 8 | See [the rules documentation](https://ty.dev/rules) for a list of all available rules. 9 | 10 | Valid severities are: 11 | 12 | * `ignore`: Disable the rule. 13 | * `warn`: Enable the rule and create a warning diagnostic. 14 | * `error`: Enable the rule and create an error diagnostic. 15 | ty will exit with a non-zero code if any error diagnostics are emitted. 16 | 17 | **Default value**: `{...}` 18 | 19 | **Type**: `dict[RuleName, "ignore" | "warn" | "error"]` 20 | 21 | **Example usage** (`pyproject.toml`): 22 | 23 | ```toml 24 | [tool.ty.rules] 25 | possibly-unresolved-reference = "warn" 26 | division-by-zero = "ignore" 27 | ``` 28 | 29 | --- 30 | 31 | ## `environment` 32 | 33 | #### `extra-paths` 34 | 35 | List of user-provided paths that should take first priority in the module resolution. 36 | Examples in other type checkers are mypy's `MYPYPATH` environment variable, 37 | or pyright's `stubPath` configuration setting. 38 | 39 | **Default value**: `[]` 40 | 41 | **Type**: `list[str]` 42 | 43 | **Example usage** (`pyproject.toml`): 44 | 45 | ```toml 46 | [tool.ty.environment] 47 | extra-paths = ["~/shared/my-search-path"] 48 | ``` 49 | 50 | --- 51 | 52 | #### `python` 53 | 54 | Path to the Python installation from which ty resolves type information and third-party dependencies. 55 | 56 | ty will search in the path's `site-packages` directories for type information and 57 | third-party imports. 58 | 59 | This option is commonly used to specify the path to a virtual environment. 60 | 61 | **Default value**: `null` 62 | 63 | **Type**: `str` 64 | 65 | **Example usage** (`pyproject.toml`): 66 | 67 | ```toml 68 | [tool.ty.environment] 69 | python = "./.venv" 70 | ``` 71 | 72 | --- 73 | 74 | #### `python-platform` 75 | 76 | Specifies the target platform that will be used to analyze the source code. 77 | If specified, ty will understand conditions based on comparisons with `sys.platform`, such 78 | as are commonly found in typeshed to reflect the differing contents of the standard library across platforms. 79 | 80 | If no platform is specified, ty will use the current platform: 81 | - `win32` for Windows 82 | - `darwin` for macOS 83 | - `android` for Android 84 | - `ios` for iOS 85 | - `linux` for everything else 86 | 87 | **Default value**: `
10 |
34 |
35 | ## `call-non-callable`
36 |
37 | **Default level**: error
38 |
39 | detects byte strings in type annotation positions
11 | 12 | ### What it does 13 | Checks for byte-strings in type annotation positions. 14 | 15 | ### Why is this bad? 16 | Static analysis tools like ty can't analyse type annotations that use byte-string notation. 17 | 18 | ### Examples 19 | ```python 20 | def test(): -> b"int": 21 | ... 22 | ``` 23 | 24 | Use instead: 25 | ```python 26 | def test(): -> "int": 27 | ... 28 | ``` 29 | 30 | ### Links 31 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20byte-string-type-annotation) 32 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fstring_annotation.rs#L36) 33 |
40 |
57 |
58 | ## `conflicting-argument-forms`
59 |
60 | **Default level**: error
61 |
62 | detects calls to non-callable objects
41 | 42 | ### What it does 43 | Checks for calls to non-callable objects. 44 | 45 | ### Why is this bad? 46 | Calling a non-callable object will raise a `TypeError` at runtime. 47 | 48 | ### Examples 49 | ```python 50 | 4() # TypeError: 'int' object is not callable 51 | ``` 52 | 53 | ### Links 54 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20call-non-callable) 55 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L91) 56 |
63 |
88 |
89 | ## `conflicting-declarations`
90 |
91 | **Default level**: error
92 |
93 | detects when an argument is used as both a value and a type form in a call
64 | 65 | ### What it does 66 | Checks whether an argument is used as both a value and a type form in a call. 67 | 68 | ### Why is this bad? 69 | Such calls have confusing semantics and often indicate a logic error. 70 | 71 | ### Examples 72 | ```python 73 | from typing import reveal_type 74 | from ty_extensions import is_fully_static 75 | 76 | if flag: 77 | f = repr # Expects a value 78 | else: 79 | f = is_fully_static # Expects a type form 80 | 81 | f(int) # error 82 | ``` 83 | 84 | ### Links 85 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20conflicting-argument-forms) 86 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L135) 87 |
94 |
118 |
119 | ## `conflicting-metaclass`
120 |
121 | **Default level**: error
122 |
123 | detects conflicting declarations
95 | 96 | ### What it does 97 | Checks whether a variable has been declared as two conflicting types. 98 | 99 | ### Why is this bad 100 | A variable with two conflicting declarations likely indicates a mistake. 101 | Moreover, it could lead to incorrect or ill-defined type inference for 102 | other code that relies on these variables. 103 | 104 | ### Examples 105 | ```python 106 | if b: 107 | a: int 108 | else: 109 | a: str 110 | 111 | a = 1 112 | ``` 113 | 114 | ### Links 115 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20conflicting-declarations) 116 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L161) 117 |
124 |
149 |
150 | ## `cyclic-class-definition`
151 |
152 | **Default level**: error
153 |
154 | detects conflicting metaclasses
125 | 126 | ### What it does 127 | Checks for class definitions where the metaclass of the class 128 | being created would not be a subclass of the metaclasses of 129 | all the class's bases. 130 | 131 | ### Why is it bad? 132 | Such a class definition raises a `TypeError` at runtime. 133 | 134 | ### Examples 135 | ```python 136 | class M1(type): ... 137 | class M2(type): ... 138 | class A(metaclass=M1): ... 139 | class B(metaclass=M2): ... 140 | 141 | ## TypeError: metaclass conflict 142 | class C(A, B): ... 143 | ``` 144 | 145 | ### Links 146 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20conflicting-metaclass) 147 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L186) 148 |
155 |
180 |
181 | ## `duplicate-base`
182 |
183 | **Default level**: error
184 |
185 | detects cyclic class definitions
156 | 157 | ### What it does 158 | Checks for class definitions in stub files that inherit 159 | (directly or indirectly) from themselves. 160 | 161 | ### Why is it bad? 162 | Although forward references are natively supported in stub files, 163 | inheritance cycles are still disallowed, as it is impossible to 164 | resolve a consistent [method resolution order] for a class that 165 | inherits from itself. 166 | 167 | ### Examples 168 | ```python 169 | ## foo.pyi 170 | class A(B): ... 171 | class B(A): ... 172 | ``` 173 | 174 | [method resolution order]: https://docs.python.org/3/glossary.html#term-method-resolution-order 175 | 176 | ### Links 177 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20cyclic-class-definition) 178 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L212) 179 |
186 |
206 |
207 | ## `escape-character-in-forward-annotation`
208 |
209 | **Default level**: error
210 |
211 | detects class definitions with duplicate bases
187 | 188 | ### What it does 189 | Checks for class definitions with duplicate bases. 190 | 191 | ### Why is this bad? 192 | Class definitions with duplicate bases raise `TypeError` at runtime. 193 | 194 | ### Examples 195 | ```python 196 | class A: ... 197 | 198 | ## TypeError: duplicate base class 199 | class B(A, A): ... 200 | ``` 201 | 202 | ### Links 203 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20duplicate-base) 204 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L256) 205 |
212 |
220 |
221 | ## `fstring-type-annotation`
222 |
223 | **Default level**: error
224 |
225 | detects forward type annotations with escape characters
213 | 214 | TODO #14889 215 | 216 | ### Links 217 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20escape-character-in-forward-annotation) 218 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fstring_annotation.rs#L120) 219 |
226 |
250 |
251 | ## `implicit-concatenated-string-type-annotation`
252 |
253 | **Default level**: error
254 |
255 | detects F-strings in type annotation positions
227 | 228 | ### What it does 229 | Checks for f-strings in type annotation positions. 230 | 231 | ### Why is this bad? 232 | Static analysis tools like ty can't analyse type annotations that use f-string notation. 233 | 234 | ### Examples 235 | ```python 236 | def test(): -> f"int": 237 | ... 238 | ``` 239 | 240 | Use instead: 241 | ```python 242 | def test(): -> "int": 243 | ... 244 | ``` 245 | 246 | ### Links 247 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20fstring-type-annotation) 248 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fstring_annotation.rs#L11) 249 |
256 |
280 |
281 | ## `incompatible-slots`
282 |
283 | **Default level**: error
284 |
285 | detects implicit concatenated strings in type annotations
257 | 258 | ### What it does 259 | Checks for implicit concatenated strings in type annotation positions. 260 | 261 | ### Why is this bad? 262 | Static analysis tools like ty can't analyse type annotations that use implicit concatenated strings. 263 | 264 | ### Examples 265 | ```python 266 | def test(): -> "Literal[" "5" "]": 267 | ... 268 | ``` 269 | 270 | Use instead: 271 | ```python 272 | def test(): -> "Literal[5]": 273 | ... 274 | ``` 275 | 276 | ### Links 277 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20implicit-concatenated-string-type-annotation) 278 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fstring_annotation.rs#L86) 279 |
286 | detects class definitions whose MRO has conflicting
287 |
288 | ### What it does
289 | Checks for classes whose bases define incompatible `__slots__`.
290 |
291 | ### Why is this bad?
292 | Inheriting from bases with incompatible `__slots__`s
293 | will lead to a `TypeError` at runtime.
294 |
295 | Classes with no or empty `__slots__` are always compatible:
296 |
297 | ```python
298 | class A: ...
299 | class B:
300 | __slots__ = ()
301 | class C:
302 | __slots__ = ("a", "b")
303 |
304 | ## fine
305 | class D(A, B, C): ...
306 | ```
307 |
308 | Multiple inheritance from more than one different class
309 | defining non-empty `__slots__` is not allowed:
310 |
311 | ```python
312 | class A:
313 | __slots__ = ("a", "b")
314 |
315 | class B:
316 | __slots__ = ("a", "b") # Even if the values are the same
317 |
318 | ## TypeError: multiple bases have instance lay-out conflict
319 | class C(A, B): ...
320 | ```
321 |
322 | ### Known problems
323 | Dynamic (not tuple or string literal) `__slots__` are not checked.
324 | Additionally, classes inheriting from built-in classes with implicit layouts
325 | like `str` or `int` are also not checked.
326 |
327 | ```pycon
328 | >>> hasattr(int, "__slots__")
329 | False
330 | >>> hasattr(str, "__slots__")
331 | False
332 | >>> class A(int, str): ...
333 | Traceback (most recent call last):
334 | File "", line 1, in
335 | class A(int, str): ...
336 | TypeError: multiple bases have instance lay-out conflict
337 | ```
338 |
339 | ### Links
340 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20incompatible-slots)
341 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L277)
342 |
343 |
344 | ## `inconsistent-mro`
345 |
346 | **Default level**: error
347 |
348 | detects class definitions whose MRO has conflicting __slots__
287 |
288 | ### What it does
289 | Checks for classes whose bases define incompatible `__slots__`.
290 |
291 | ### Why is this bad?
292 | Inheriting from bases with incompatible `__slots__`s
293 | will lead to a `TypeError` at runtime.
294 |
295 | Classes with no or empty `__slots__` are always compatible:
296 |
297 | ```python
298 | class A: ...
299 | class B:
300 | __slots__ = ()
301 | class C:
302 | __slots__ = ("a", "b")
303 |
304 | ## fine
305 | class D(A, B, C): ...
306 | ```
307 |
308 | Multiple inheritance from more than one different class
309 | defining non-empty `__slots__` is not allowed:
310 |
311 | ```python
312 | class A:
313 | __slots__ = ("a", "b")
314 |
315 | class B:
316 | __slots__ = ("a", "b") # Even if the values are the same
317 |
318 | ## TypeError: multiple bases have instance lay-out conflict
319 | class C(A, B): ...
320 | ```
321 |
322 | ### Known problems
323 | Dynamic (not tuple or string literal) `__slots__` are not checked.
324 | Additionally, classes inheriting from built-in classes with implicit layouts
325 | like `str` or `int` are also not checked.
326 |
327 | ```pycon
328 | >>> hasattr(int, "__slots__")
329 | False
330 | >>> hasattr(str, "__slots__")
331 | False
332 | >>> class A(int, str): ...
333 | Traceback (most recent call last):
334 | File "
349 |
372 |
373 | ## `index-out-of-bounds`
374 |
375 | **Default level**: error
376 |
377 | detects class definitions with an inconsistent MRO
350 | 351 | ### What it does 352 | Checks for classes with an inconsistent [method resolution order] (MRO). 353 | 354 | ### Why is this bad? 355 | Classes with an inconsistent MRO will raise a `TypeError` at runtime. 356 | 357 | ### Examples 358 | ```python 359 | class A: ... 360 | class B(A): ... 361 | 362 | ## TypeError: Cannot create a consistent method resolution order 363 | class C(A, B): ... 364 | ``` 365 | 366 | [method resolution order]: https://docs.python.org/3/glossary.html#term-method-resolution-order 367 | 368 | ### Links 369 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20inconsistent-mro) 370 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L363) 371 |
378 |
397 |
398 | ## `invalid-argument-type`
399 |
400 | **Default level**: error
401 |
402 | detects index out of bounds errors
379 | 380 | ### What it does 381 | Checks for attempts to use an out of bounds index to get an item from 382 | a container. 383 | 384 | ### Why is this bad? 385 | Using an out of bounds index will raise an `IndexError` at runtime. 386 | 387 | ### Examples 388 | ```python 389 | t = (0, 1, 2) 390 | t[3] # IndexError: tuple index out of range 391 | ``` 392 | 393 | ### Links 394 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20index-out-of-bounds) 395 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L387) 396 |
403 |
423 |
424 | ## `invalid-assignment`
425 |
426 | **Default level**: error
427 |
428 | detects call arguments whose type is not assignable to the corresponding typed parameter
404 | 405 | ### What it does 406 | Detects call arguments whose type is not assignable to the corresponding typed parameter. 407 | 408 | ### Why is this bad? 409 | Passing an argument of a type the function (or callable object) does not accept violates 410 | the expectations of the function author and may cause unexpected runtime errors within the 411 | body of the function. 412 | 413 | ### Examples 414 | ```python 415 | def func(x: int): ... 416 | func("foo") # error: [invalid-argument-type] 417 | ``` 418 | 419 | ### Links 420 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-argument-type) 421 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L407) 422 |
429 |
450 |
451 | ## `invalid-attribute-access`
452 |
453 | **Default level**: error
454 |
455 | detects invalid assignments
430 | 431 | ### What it does 432 | Checks for assignments where the type of the value 433 | is not [assignable to] the type of the assignee. 434 | 435 | ### Why is this bad? 436 | Such assignments break the rules of the type system and 437 | weaken a type checker's ability to accurately reason about your code. 438 | 439 | ### Examples 440 | ```python 441 | a: int = '' 442 | ``` 443 | 444 | [assignable to]: https://typing.python.org/en/latest/spec/glossary.html#term-assignable 445 | 446 | ### Links 447 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-assignment) 448 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L447) 449 |
456 |
483 |
484 | ## `invalid-base`
485 |
486 | **Default level**: error
487 |
488 | Invalid attribute access
457 | 458 | ### What it does 459 | Checks for assignments to class variables from instances 460 | and assignments to instance variables from its class. 461 | 462 | ### Why is this bad? 463 | Incorrect assignments break the rules of the type system and 464 | weaken a type checker's ability to accurately reason about your code. 465 | 466 | ### Examples 467 | ```python 468 | class C: 469 | class_var: ClassVar[int] = 1 470 | instance_var: int 471 | 472 | C.class_var = 3 # okay 473 | C().class_var = 3 # error: Cannot assign to class variable 474 | 475 | C().instance_var = 3 # okay 476 | C.instance_var = 3 # error: Cannot assign to instance variable 477 | ``` 478 | 479 | ### Links 480 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-attribute-access) 481 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1395) 482 |
489 |
506 |
507 | ## `invalid-context-manager`
508 |
509 | **Default level**: error
510 |
511 | detects class bases that will cause the class definition to raise an exception at runtime
490 | 491 | ### What it does 492 | Checks for class definitions that have bases which are not instances of `type`. 493 | 494 | ### Why is this bad? 495 | Class definitions with bases like this will lead to `TypeError` being raised at runtime. 496 | 497 | ### Examples 498 | ```python 499 | class A(42): ... # error: [invalid-base] 500 | ``` 501 | 502 | ### Links 503 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-base) 504 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L469) 505 |
512 |
532 |
533 | ## `invalid-declaration`
534 |
535 | **Default level**: error
536 |
537 | detects expressions used in with statements that don't implement the context manager protocol
513 | 514 | ### What it does 515 | Checks for expressions used in `with` statements 516 | that do not implement the context manager protocol. 517 | 518 | ### Why is this bad? 519 | Such a statement will raise `TypeError` at runtime. 520 | 521 | ### Examples 522 | ```python 523 | ## TypeError: 'int' object does not support the context manager protocol 524 | with 1: 525 | print(2) 526 | ``` 527 | 528 | ### Links 529 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-context-manager) 530 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L520) 531 |
538 |
560 |
561 | ## `invalid-exception-caught`
562 |
563 | **Default level**: error
564 |
565 | detects invalid declarations
539 | 540 | ### What it does 541 | Checks for declarations where the inferred type of an existing symbol 542 | is not [assignable to] its post-hoc declared type. 543 | 544 | ### Why is this bad? 545 | Such declarations break the rules of the type system and 546 | weaken a type checker's ability to accurately reason about your code. 547 | 548 | ### Examples 549 | ```python 550 | a = 1 551 | a: str 552 | ``` 553 | 554 | [assignable to]: https://typing.python.org/en/latest/spec/glossary.html#term-assignable 555 | 556 | ### Links 557 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-declaration) 558 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L541) 559 |
566 | detects exception handlers that catch classes that do not inherit from
567 |
568 | ### What it does
569 | Checks for exception handlers that catch non-exception classes.
570 |
571 | ### Why is this bad?
572 | Catching classes that do not inherit from `BaseException` will raise a TypeError at runtime.
573 |
574 | ### Example
575 | ```python
576 | try:
577 | 1 / 0
578 | except 1:
579 | ...
580 | ```
581 |
582 | Use instead:
583 | ```python
584 | try:
585 | 1 / 0
586 | except ZeroDivisionError:
587 | ...
588 | ```
589 |
590 | ### References
591 | - [Python documentation: except clause](https://docs.python.org/3/reference/compound_stmts.html#except-clause)
592 | - [Python documentation: Built-in Exceptions](https://docs.python.org/3/library/exceptions.html#built-in-exceptions)
593 |
594 | ### Ruff rule
595 | This rule corresponds to Ruff's [`except-with-non-exception-classes` (`B030`)](https://docs.astral.sh/ruff/rules/except-with-non-exception-classes)
596 |
597 | ### Links
598 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-exception-caught)
599 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L564)
600 |
601 |
602 | ## `invalid-generic-class`
603 |
604 | **Default level**: error
605 |
606 | detects exception handlers that catch classes that do not inherit from BaseException
567 |
568 | ### What it does
569 | Checks for exception handlers that catch non-exception classes.
570 |
571 | ### Why is this bad?
572 | Catching classes that do not inherit from `BaseException` will raise a TypeError at runtime.
573 |
574 | ### Example
575 | ```python
576 | try:
577 | 1 / 0
578 | except 1:
579 | ...
580 | ```
581 |
582 | Use instead:
583 | ```python
584 | try:
585 | 1 / 0
586 | except ZeroDivisionError:
587 | ...
588 | ```
589 |
590 | ### References
591 | - [Python documentation: except clause](https://docs.python.org/3/reference/compound_stmts.html#except-clause)
592 | - [Python documentation: Built-in Exceptions](https://docs.python.org/3/library/exceptions.html#built-in-exceptions)
593 |
594 | ### Ruff rule
595 | This rule corresponds to Ruff's [`except-with-non-exception-classes` (`B030`)](https://docs.astral.sh/ruff/rules/except-with-non-exception-classes)
596 |
597 | ### Links
598 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-exception-caught)
599 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L564)
600 |
607 |
632 |
633 | ## `invalid-legacy-type-variable`
634 |
635 | **Default level**: error
636 |
637 | detects invalid generic classes
608 | 609 | ### What it does 610 | Checks for the creation of invalid generic classes 611 | 612 | ### Why is this bad? 613 | There are several requirements that you must follow when defining a generic class. 614 | 615 | ### Examples 616 | ```python 617 | from typing import Generic, TypeVar 618 | 619 | T = TypeVar("T") # okay 620 | 621 | ## error: class uses both PEP-695 syntax and legacy syntax 622 | class C[U](Generic[T]): ... 623 | ``` 624 | 625 | ### References 626 | - [Typing spec: Generics](https://typing.python.org/en/latest/spec/generics.html#introduction) 627 | 628 | ### Links 629 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-generic-class) 630 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L600) 631 |
638 |
665 |
666 | ## `invalid-metaclass`
667 |
668 | **Default level**: error
669 |
670 | detects invalid legacy type variables
639 | 640 | ### What it does 641 | Checks for the creation of invalid legacy `TypeVar`s 642 | 643 | ### Why is this bad? 644 | There are several requirements that you must follow when creating a legacy `TypeVar`. 645 | 646 | ### Examples 647 | ```python 648 | from typing import TypeVar 649 | 650 | T = TypeVar("T") # okay 651 | Q = TypeVar("S") # error: TypeVar name must match the variable it's assigned to 652 | T = TypeVar("T") # error: TypeVars should not be redefined 653 | 654 | ## error: TypeVar must be immediately assigned to a variable 655 | def f(t: TypeVar("U")): ... 656 | ``` 657 | 658 | ### References 659 | - [Typing spec: Generics](https://typing.python.org/en/latest/spec/generics.html#introduction) 660 | 661 | ### Links 662 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-legacy-type-variable) 663 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L626) 664 |
671 | detects invalid
672 |
673 | ### What it does
674 | Checks for arguments to `metaclass=` that are invalid.
675 |
676 | ### Why is this bad?
677 | Python allows arbitrary expressions to be used as the argument to `metaclass=`.
678 | These expressions, however, need to be callable and accept the same arguments
679 | as `type.__new__`.
680 |
681 | ### Example
682 |
683 | ```python
684 | def f(): ...
685 |
686 | ## TypeError: f() takes 0 positional arguments but 3 were given
687 | class B(metaclass=f): ...
688 | ```
689 |
690 | ### References
691 | - [Python documentation: Metaclasses](https://docs.python.org/3/reference/datamodel.html#metaclasses)
692 |
693 | ### Links
694 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-metaclass)
695 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L675)
696 |
697 |
698 | ## `invalid-overload`
699 |
700 | **Default level**: error
701 |
702 | detects invalid metaclass= arguments
672 |
673 | ### What it does
674 | Checks for arguments to `metaclass=` that are invalid.
675 |
676 | ### Why is this bad?
677 | Python allows arbitrary expressions to be used as the argument to `metaclass=`.
678 | These expressions, however, need to be callable and accept the same arguments
679 | as `type.__new__`.
680 |
681 | ### Example
682 |
683 | ```python
684 | def f(): ...
685 |
686 | ## TypeError: f() takes 0 positional arguments but 3 were given
687 | class B(metaclass=f): ...
688 | ```
689 |
690 | ### References
691 | - [Python documentation: Metaclasses](https://docs.python.org/3/reference/datamodel.html#metaclasses)
692 |
693 | ### Links
694 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-metaclass)
695 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L675)
696 |
703 | detects invalid
704 |
705 | ### What it does
706 | Checks for various invalid `@overload` usages.
707 |
708 | ### Why is this bad?
709 | The `@overload` decorator is used to define functions and methods that accepts different
710 | combinations of arguments and return different types based on the arguments passed. This is
711 | mainly beneficial for type checkers. But, if the `@overload` usage is invalid, the type
712 | checker may not be able to provide correct type information.
713 |
714 | ### Example
715 |
716 | Defining only one overload:
717 |
718 | ```py
719 | from typing import overload
720 |
721 | @overload
722 | def foo(x: int) -> int: ...
723 | def foo(x: int | None) -> int | None:
724 | return x
725 | ```
726 |
727 | Or, not providing an implementation for the overloaded definition:
728 |
729 | ```py
730 | from typing import overload
731 |
732 | @overload
733 | def foo() -> None: ...
734 | @overload
735 | def foo(x: int) -> int: ...
736 | ```
737 |
738 | ### References
739 | - [Python documentation: `@overload`](https://docs.python.org/3/library/typing.html#typing.overload)
740 |
741 | ### Links
742 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-overload)
743 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L702)
744 |
745 |
746 | ## `invalid-parameter-default`
747 |
748 | **Default level**: error
749 |
750 | detects invalid @overload usages
704 |
705 | ### What it does
706 | Checks for various invalid `@overload` usages.
707 |
708 | ### Why is this bad?
709 | The `@overload` decorator is used to define functions and methods that accepts different
710 | combinations of arguments and return different types based on the arguments passed. This is
711 | mainly beneficial for type checkers. But, if the `@overload` usage is invalid, the type
712 | checker may not be able to provide correct type information.
713 |
714 | ### Example
715 |
716 | Defining only one overload:
717 |
718 | ```py
719 | from typing import overload
720 |
721 | @overload
722 | def foo(x: int) -> int: ...
723 | def foo(x: int | None) -> int | None:
724 | return x
725 | ```
726 |
727 | Or, not providing an implementation for the overloaded definition:
728 |
729 | ```py
730 | from typing import overload
731 |
732 | @overload
733 | def foo() -> None: ...
734 | @overload
735 | def foo(x: int) -> int: ...
736 | ```
737 |
738 | ### References
739 | - [Python documentation: `@overload`](https://docs.python.org/3/library/typing.html#typing.overload)
740 |
741 | ### Links
742 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-overload)
743 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L702)
744 |
751 |
770 |
771 | ## `invalid-protocol`
772 |
773 | **Default level**: error
774 |
775 | detects default values that can't be assigned to the parameter's annotated type
752 | 753 | ### What it does 754 | Checks for default values that can't be 755 | assigned to the parameter's annotated type. 756 | 757 | ### Why is this bad? 758 | This breaks the rules of the type system and 759 | weakens a type checker's ability to accurately reason about your code. 760 | 761 | ### Examples 762 | ```python 763 | def f(a: int = ''): ... 764 | ``` 765 | 766 | ### Links 767 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-parameter-default) 768 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L745) 769 |
776 | ", line 1, in
795 | class Foo(int, Protocol): ...
796 | TypeError: Protocols can only inherit from other protocols, got
797 | ```
798 |
799 | ### Links
800 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-protocol)
801 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L335)
802 |
803 |
804 | ## `invalid-raise`
805 |
806 | **Default level**: error
807 |
808 | detects invalid protocol class definitions
777 | 778 | ### What it does 779 | Checks for invalidly defined protocol classes. 780 | 781 | ### Why is this bad? 782 | An invalidly defined protocol class may lead to the type checker inferring 783 | unexpected things. It may also lead to `TypeError`s at runtime. 784 | 785 | ### Examples 786 | A `Protocol` class cannot inherit from a non-`Protocol` class; 787 | this raises a `TypeError` at runtime: 788 | 789 | ```pycon 790 | >>> from typing import Protocol 791 | >>> class Foo(int, Protocol): ... 792 | ... 793 | Traceback (most recent call last): 794 | File "
809 | detects
810 |
811 | Checks for `raise` statements that raise non-exceptions or use invalid
812 | causes for their raised exceptions.
813 |
814 | ### Why is this bad?
815 | Only subclasses or instances of `BaseException` can be raised.
816 | For an exception's cause, the same rules apply, except that `None` is also
817 | permitted. Violating these rules results in a `TypeError` at runtime.
818 |
819 | ### Examples
820 | ```python
821 | def f():
822 | try:
823 | something()
824 | except NameError:
825 | raise "oops!" from f
826 |
827 | def g():
828 | raise NotImplemented from 42
829 | ```
830 |
831 | Use instead:
832 | ```python
833 | def f():
834 | try:
835 | something()
836 | except NameError as e:
837 | raise RuntimeError("oops!") from e
838 |
839 | def g():
840 | raise NotImplementedError from None
841 | ```
842 |
843 | ### References
844 | - [Python documentation: The `raise` statement](https://docs.python.org/3/reference/simple_stmts.html#raise)
845 | - [Python documentation: Built-in Exceptions](https://docs.python.org/3/library/exceptions.html#built-in-exceptions)
846 |
847 | ### Links
848 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-raise)
849 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L765)
850 |
851 |
852 | ## `invalid-return-type`
853 |
854 | **Default level**: error
855 |
856 | detects raise statements that raise invalid exceptions or use invalid causes
810 |
811 | Checks for `raise` statements that raise non-exceptions or use invalid
812 | causes for their raised exceptions.
813 |
814 | ### Why is this bad?
815 | Only subclasses or instances of `BaseException` can be raised.
816 | For an exception's cause, the same rules apply, except that `None` is also
817 | permitted. Violating these rules results in a `TypeError` at runtime.
818 |
819 | ### Examples
820 | ```python
821 | def f():
822 | try:
823 | something()
824 | except NameError:
825 | raise "oops!" from f
826 |
827 | def g():
828 | raise NotImplemented from 42
829 | ```
830 |
831 | Use instead:
832 | ```python
833 | def f():
834 | try:
835 | something()
836 | except NameError as e:
837 | raise RuntimeError("oops!") from e
838 |
839 | def g():
840 | raise NotImplementedError from None
841 | ```
842 |
843 | ### References
844 | - [Python documentation: The `raise` statement](https://docs.python.org/3/reference/simple_stmts.html#raise)
845 | - [Python documentation: Built-in Exceptions](https://docs.python.org/3/library/exceptions.html#built-in-exceptions)
846 |
847 | ### Links
848 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-raise)
849 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L765)
850 |
857 |
875 |
876 | ## `invalid-super-argument`
877 |
878 | **Default level**: error
879 |
880 | detects returned values that can't be assigned to the function's annotated return type
858 | 859 | ### What it does 860 | Detects returned values that can't be assigned to the function's annotated return type. 861 | 862 | ### Why is this bad? 863 | Returning an object of a type incompatible with the annotated return type may cause confusion to the user calling the function. 864 | 865 | ### Examples 866 | ```python 867 | def func() -> int: 868 | return "a" # error: [invalid-return-type] 869 | ``` 870 | 871 | ### Links 872 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-return-type) 873 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L428) 874 |
881 | detects invalid arguments for
882 |
883 | ### What it does
884 | Detects `super()` calls where:
885 | - the first argument is not a valid class literal, or
886 | - the second argument is not an instance or subclass of the first argument.
887 |
888 | ### Why is this bad?
889 | `super(type, obj)` expects:
890 | - the first argument to be a class,
891 | - and the second argument to satisfy one of the following:
892 | - `isinstance(obj, type)` is `True`
893 | - `issubclass(obj, type)` is `True`
894 |
895 | Violating this relationship will raise a `TypeError` at runtime.
896 |
897 | ### Examples
898 | ```python
899 | class A:
900 | ...
901 | class B(A):
902 | ...
903 |
904 | super(A, B()) # it's okay! `A` satisfies `isinstance(B(), A)`
905 |
906 | super(A(), B()) # error: `A()` is not a class
907 |
908 | super(B, A()) # error: `A()` does not satisfy `isinstance(A(), B)`
909 | super(B, A) # error: `A` does not satisfy `issubclass(A, B)`
910 | ```
911 |
912 | ### References
913 | - [Python documentation: super()](https://docs.python.org/3/library/functions.html#super)
914 |
915 | ### Links
916 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-super-argument)
917 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L808)
918 |
919 |
920 | ## `invalid-syntax-in-forward-annotation`
921 |
922 | **Default level**: error
923 |
924 | detects invalid arguments for super()
882 |
883 | ### What it does
884 | Detects `super()` calls where:
885 | - the first argument is not a valid class literal, or
886 | - the second argument is not an instance or subclass of the first argument.
887 |
888 | ### Why is this bad?
889 | `super(type, obj)` expects:
890 | - the first argument to be a class,
891 | - and the second argument to satisfy one of the following:
892 | - `isinstance(obj, type)` is `True`
893 | - `issubclass(obj, type)` is `True`
894 |
895 | Violating this relationship will raise a `TypeError` at runtime.
896 |
897 | ### Examples
898 | ```python
899 | class A:
900 | ...
901 | class B(A):
902 | ...
903 |
904 | super(A, B()) # it's okay! `A` satisfies `isinstance(B(), A)`
905 |
906 | super(A(), B()) # error: `A()` is not a class
907 |
908 | super(B, A()) # error: `A()` does not satisfy `isinstance(A(), B)`
909 | super(B, A) # error: `A` does not satisfy `issubclass(A, B)`
910 | ```
911 |
912 | ### References
913 | - [Python documentation: super()](https://docs.python.org/3/library/functions.html#super)
914 |
915 | ### Links
916 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-super-argument)
917 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L808)
918 |
925 |
933 |
934 | ## `invalid-type-alias-type`
935 |
936 | **Default level**: error
937 |
938 | detects invalid syntax in forward annotations
926 | 927 | TODO #14889 928 | 929 | ### Links 930 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-syntax-in-forward-annotation) 931 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fstring_annotation.rs#L111) 932 |
939 |
959 |
960 | ## `invalid-type-checking-constant`
961 |
962 | **Default level**: error
963 |
964 | detects invalid TypeAliasType definitions
940 | 941 | ### What it does 942 | Checks for the creation of invalid `TypeAliasType`s 943 | 944 | ### Why is this bad? 945 | There are several requirements that you must follow when creating a `TypeAliasType`. 946 | 947 | ### Examples 948 | ```python 949 | from typing import TypeAliasType 950 | 951 | IntOrStr = TypeAliasType("IntOrStr", int | str) # okay 952 | NewAlias = TypeAliasType(get_name(), int) # error: TypeAliasType name must be a string literal 953 | ``` 954 | 955 | ### Links 956 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-alias-type) 957 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L654) 958 |
965 | detects invalid
966 |
967 | ### What it does
968 | Checks for a value other than `False` assigned to the `TYPE_CHECKING` variable, or an
969 | annotation not assignable from `bool`.
970 |
971 | ### Why is this bad?
972 | The name `TYPE_CHECKING` is reserved for a flag that can be used to provide conditional
973 | code seen only by the type checker, and not at runtime. Normally this flag is imported from
974 | `typing` or `typing_extensions`, but it can also be defined locally. If defined locally, it
975 | must be assigned the value `False` at runtime; the type checker will consider its value to
976 | be `True`. If annotated, it must be annotated as a type that can accept `bool` values.
977 |
978 | ### Examples
979 | ```python
980 | TYPE_CHECKING: str
981 | TYPE_CHECKING = ''
982 | ```
983 |
984 | ### Links
985 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-checking-constant)
986 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L847)
987 |
988 |
989 | ## `invalid-type-form`
990 |
991 | **Default level**: error
992 |
993 | detects invalid TYPE_CHECKING constant assignments
966 |
967 | ### What it does
968 | Checks for a value other than `False` assigned to the `TYPE_CHECKING` variable, or an
969 | annotation not assignable from `bool`.
970 |
971 | ### Why is this bad?
972 | The name `TYPE_CHECKING` is reserved for a flag that can be used to provide conditional
973 | code seen only by the type checker, and not at runtime. Normally this flag is imported from
974 | `typing` or `typing_extensions`, but it can also be defined locally. If defined locally, it
975 | must be assigned the value `False` at runtime; the type checker will consider its value to
976 | be `True`. If annotated, it must be annotated as a type that can accept `bool` values.
977 |
978 | ### Examples
979 | ```python
980 | TYPE_CHECKING: str
981 | TYPE_CHECKING = ''
982 | ```
983 |
984 | ### Links
985 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-checking-constant)
986 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L847)
987 |
994 |
1017 |
1018 | ## `invalid-type-variable-constraints`
1019 |
1020 | **Default level**: error
1021 |
1022 | detects invalid type forms
995 | 996 | ### What it does 997 | Checks for expressions that are used as [type expressions] 998 | but cannot validly be interpreted as such. 999 | 1000 | ### Why is this bad? 1001 | Such expressions cannot be understood by ty. 1002 | In some cases, they might raise errors at runtime. 1003 | 1004 | ### Examples 1005 | ```python 1006 | from typing import Annotated 1007 | 1008 | a: type[1] # `1` is not a type 1009 | b: Annotated[int] # `Annotated` expects at least two arguments 1010 | ``` 1011 | [type expressions]: https://typing.python.org/en/latest/spec/annotations.html#type-and-annotation-expressions 1012 | 1013 | ### Links 1014 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-form) 1015 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L871) 1016 |
1023 |
1051 |
1052 | ## `missing-argument`
1053 |
1054 | **Default level**: error
1055 |
1056 | detects invalid type variable constraints
1024 | 1025 | ### What it does 1026 | Checks for constrained [type variables] with only one constraint. 1027 | 1028 | ### Why is this bad? 1029 | A constrained type variable must have at least two constraints. 1030 | 1031 | ### Examples 1032 | ```python 1033 | from typing import TypeVar 1034 | 1035 | T = TypeVar('T', str) # invalid constrained TypeVar 1036 | ``` 1037 | 1038 | Use instead: 1039 | ```python 1040 | T = TypeVar('T', str, int) # valid constrained TypeVar 1041 | ## or 1042 | T = TypeVar('T', bound=str) # valid bound TypeVar 1043 | ``` 1044 | 1045 | [type variables]: https://docs.python.org/3/library/typing.html#typing.TypeVar 1046 | 1047 | ### Links 1048 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-variable-constraints) 1049 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L895) 1050 |
1057 |
1075 |
1076 | ## `no-matching-overload`
1077 |
1078 | **Default level**: error
1079 |
1080 | detects missing required arguments in a call
1058 | 1059 | ### What it does 1060 | Checks for missing required arguments in a call. 1061 | 1062 | ### Why is this bad? 1063 | Failing to provide a required argument will raise a `TypeError` at runtime. 1064 | 1065 | ### Examples 1066 | ```python 1067 | def func(x: int): ... 1068 | func() # TypeError: func() missing 1 required positional argument: 'x' 1069 | ``` 1070 | 1071 | ### Links 1072 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20missing-argument) 1073 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L924) 1074 |
1081 |
1103 |
1104 | ## `non-subscriptable`
1105 |
1106 | **Default level**: error
1107 |
1108 | detects calls that do not match any overload
1082 | 1083 | ### What it does 1084 | Checks for calls to an overloaded function that do not match any of the overloads. 1085 | 1086 | ### Why is this bad? 1087 | Failing to provide the correct arguments to one of the overloads will raise a `TypeError` 1088 | at runtime. 1089 | 1090 | ### Examples 1091 | ```python 1092 | @overload 1093 | def func(x: int): ... 1094 | @overload 1095 | def func(x: bool): ... 1096 | func("string") # error: [no-matching-overload] 1097 | ``` 1098 | 1099 | ### Links 1100 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20no-matching-overload) 1101 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L943) 1102 |
1109 |
1126 |
1127 | ## `not-iterable`
1128 |
1129 | **Default level**: error
1130 |
1131 | detects subscripting objects that do not support subscripting
1110 | 1111 | ### What it does 1112 | Checks for subscripting objects that do not support subscripting. 1113 | 1114 | ### Why is this bad? 1115 | Subscripting an object that does not support it will raise a `TypeError` at runtime. 1116 | 1117 | ### Examples 1118 | ```python 1119 | 4[1] # TypeError: 'int' object is not subscriptable 1120 | ``` 1121 | 1122 | ### Links 1123 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20non-subscriptable) 1124 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L966) 1125 |
1132 |
1151 |
1152 | ## `parameter-already-assigned`
1153 |
1154 | **Default level**: error
1155 |
1156 | detects iteration over an object that is not iterable
1133 | 1134 | ### What it does 1135 | Checks for objects that are not iterable but are used in a context that requires them to be. 1136 | 1137 | ### Why is this bad? 1138 | Iterating over an object that is not iterable will raise a `TypeError` at runtime. 1139 | 1140 | ### Examples 1141 | 1142 | ```python 1143 | for i in 34: # TypeError: 'int' object is not iterable 1144 | pass 1145 | ``` 1146 | 1147 | ### Links 1148 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20not-iterable) 1149 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L984) 1150 |
1157 |
1177 |
1178 | ## `raw-string-type-annotation`
1179 |
1180 | **Default level**: error
1181 |
1182 | detects multiple arguments for the same parameter
1158 | 1159 | ### What it does 1160 | Checks for calls which provide more than one argument for a single parameter. 1161 | 1162 | ### Why is this bad? 1163 | Providing multiple values for a single parameter will raise a `TypeError` at runtime. 1164 | 1165 | ### Examples 1166 | 1167 | ```python 1168 | def f(x: int) -> int: ... 1169 | 1170 | f(1, x=2) # Error raised here 1171 | ``` 1172 | 1173 | ### Links 1174 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20parameter-already-assigned) 1175 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1035) 1176 |
1183 |
1207 |
1208 | ## `static-assert-error`
1209 |
1210 | **Default level**: error
1211 |
1212 | detects raw strings in type annotation positions
1184 | 1185 | ### What it does 1186 | Checks for raw-strings in type annotation positions. 1187 | 1188 | ### Why is this bad? 1189 | Static analysis tools like ty can't analyse type annotations that use raw-string notation. 1190 | 1191 | ### Examples 1192 | ```python 1193 | def test(): -> r"int": 1194 | ... 1195 | ``` 1196 | 1197 | Use instead: 1198 | ```python 1199 | def test(): -> "int": 1200 | ... 1201 | ``` 1202 | 1203 | ### Links 1204 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20raw-string-type-annotation) 1205 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fstring_annotation.rs#L61) 1206 |
1213 |
1236 |
1237 | ## `subclass-of-final-class`
1238 |
1239 | **Default level**: error
1240 |
1241 | Failed static assertion
1214 | 1215 | ### What it does 1216 | Makes sure that the argument of `static_assert` is statically known to be true. 1217 | 1218 | ### Why is this bad? 1219 | A `static_assert` call represents an explicit request from the user 1220 | for the type checker to emit an error if the argument cannot be verified 1221 | to evaluate to `True` in a boolean context. 1222 | 1223 | ### Examples 1224 | ```python 1225 | from ty_extensions import static_assert 1226 | 1227 | static_assert(1 + 1 == 3) # error: evaluates to `False` 1228 | 1229 | static_assert(int(2.0 * 3.0) == 6) # error: does not have a statically known truthiness 1230 | ``` 1231 | 1232 | ### Links 1233 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20static-assert-error) 1234 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1371) 1235 |
1242 |
1264 |
1265 | ## `too-many-positional-arguments`
1266 |
1267 | **Default level**: error
1268 |
1269 | detects subclasses of final classes
1243 | 1244 | ### What it does 1245 | Checks for classes that subclass final classes. 1246 | 1247 | ### Why is this bad? 1248 | Decorating a class with `@final` declares to the type checker that it should not be subclassed. 1249 | 1250 | ### Example 1251 | 1252 | ```python 1253 | from typing import final 1254 | 1255 | @final 1256 | class A: ... 1257 | class B(A): ... # Error raised here 1258 | ``` 1259 | 1260 | ### Links 1261 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20subclass-of-final-class) 1262 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1126) 1263 |
1270 |
1290 |
1291 | ## `type-assertion-failure`
1292 |
1293 | **Default level**: error
1294 |
1295 | detects calls passing too many positional arguments
1271 | 1272 | ### What it does 1273 | Checks for calls that pass more positional arguments than the callable can accept. 1274 | 1275 | ### Why is this bad? 1276 | Passing too many positional arguments will raise `TypeError` at runtime. 1277 | 1278 | ### Example 1279 | 1280 | ```python 1281 | def f(): ... 1282 | 1283 | f("foo") # Error raised here 1284 | ``` 1285 | 1286 | ### Links 1287 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20too-many-positional-arguments) 1288 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1171) 1289 |
1296 |
1317 |
1318 | ## `unavailable-implicit-super-arguments`
1319 |
1320 | **Default level**: error
1321 |
1322 | detects failed type assertions
1297 | 1298 | ### What it does 1299 | Checks for `assert_type()` and `assert_never()` calls where the actual type 1300 | is not the same as the asserted type. 1301 | 1302 | ### Why is this bad? 1303 | `assert_type()` allows confirming the inferred type of a certain value. 1304 | 1305 | ### Example 1306 | 1307 | ```python 1308 | def _(x: int): 1309 | assert_type(x, int) # fine 1310 | assert_type(x, str) # error: Actual type does not match asserted type 1311 | ``` 1312 | 1313 | ### Links 1314 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20type-assertion-failure) 1315 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1149) 1316 |
1323 | detects invalid
1324 |
1325 | ### What it does
1326 | Detects invalid `super()` calls where implicit arguments like the enclosing class or first method argument are unavailable.
1327 |
1328 | ### Why is this bad?
1329 | When `super()` is used without arguments, Python tries to find two things:
1330 | the nearest enclosing class and the first argument of the immediately enclosing function (typically self or cls).
1331 | If either of these is missing, the call will fail at runtime with a `RuntimeError`.
1332 |
1333 | ### Examples
1334 | ```python
1335 | super() # error: no enclosing class or function found
1336 |
1337 | def func():
1338 | super() # error: no enclosing class or first argument exists
1339 |
1340 | class A:
1341 | f = super() # error: no enclosing function to provide the first argument
1342 |
1343 | def method(self):
1344 | def nested():
1345 | super() # error: first argument does not exist in this nested function
1346 |
1347 | lambda: super() # error: first argument does not exist in this lambda
1348 |
1349 | (super() for _ in range(10)) # error: argument is not available in generator expression
1350 |
1351 | super() # okay! both enclosing class and first argument are available
1352 | ```
1353 |
1354 | ### References
1355 | - [Python documentation: super()](https://docs.python.org/3/library/functions.html#super)
1356 |
1357 | ### Links
1358 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unavailable-implicit-super-arguments)
1359 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1192)
1360 |
1361 |
1362 | ## `unknown-argument`
1363 |
1364 | **Default level**: error
1365 |
1366 | detects invalid super() calls where implicit arguments are unavailable.
1324 |
1325 | ### What it does
1326 | Detects invalid `super()` calls where implicit arguments like the enclosing class or first method argument are unavailable.
1327 |
1328 | ### Why is this bad?
1329 | When `super()` is used without arguments, Python tries to find two things:
1330 | the nearest enclosing class and the first argument of the immediately enclosing function (typically self or cls).
1331 | If either of these is missing, the call will fail at runtime with a `RuntimeError`.
1332 |
1333 | ### Examples
1334 | ```python
1335 | super() # error: no enclosing class or function found
1336 |
1337 | def func():
1338 | super() # error: no enclosing class or first argument exists
1339 |
1340 | class A:
1341 | f = super() # error: no enclosing function to provide the first argument
1342 |
1343 | def method(self):
1344 | def nested():
1345 | super() # error: first argument does not exist in this nested function
1346 |
1347 | lambda: super() # error: first argument does not exist in this lambda
1348 |
1349 | (super() for _ in range(10)) # error: argument is not available in generator expression
1350 |
1351 | super() # okay! both enclosing class and first argument are available
1352 | ```
1353 |
1354 | ### References
1355 | - [Python documentation: super()](https://docs.python.org/3/library/functions.html#super)
1356 |
1357 | ### Links
1358 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unavailable-implicit-super-arguments)
1359 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1192)
1360 |
1367 |
1387 |
1388 | ## `unresolved-attribute`
1389 |
1390 | **Default level**: error
1391 |
1392 | detects unknown keyword arguments in calls
1368 | 1369 | ### What it does 1370 | Checks for keyword arguments in calls that don't match any parameter of the callable. 1371 | 1372 | ### Why is this bad? 1373 | Providing an unknown keyword argument will raise `TypeError` at runtime. 1374 | 1375 | ### Example 1376 | 1377 | ```python 1378 | def f(x: int) -> int: ... 1379 | 1380 | f(x=1, y=2) # Error raised here 1381 | ``` 1382 | 1383 | ### Links 1384 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unknown-argument) 1385 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1249) 1386 |
1393 |
1414 |
1415 | ## `unresolved-import`
1416 |
1417 | **Default level**: error
1418 |
1419 | detects references to unresolved attributes
1394 | 1395 | ### What it does 1396 | Checks for unresolved attributes. 1397 | 1398 | ### Why is this bad? 1399 | Accessing an unbound attribute will raise an `AttributeError` at runtime. 1400 | An unresolved attribute is not guaranteed to exist from the type alone, 1401 | so this could also indicate that the object is not of the type that the user expects. 1402 | 1403 | ### Examples 1404 | ```python 1405 | class A: ... 1406 | 1407 | A().foo # AttributeError: 'A' object has no attribute 'foo' 1408 | ``` 1409 | 1410 | ### Links 1411 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-attribute) 1412 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1270) 1413 |
1420 |
1438 |
1439 | ## `unresolved-reference`
1440 |
1441 | **Default level**: error
1442 |
1443 | detects unresolved imports
1421 | 1422 | ### What it does 1423 | Checks for import statements for which the module cannot be resolved. 1424 | 1425 | ### Why is this bad? 1426 | Importing a module that cannot be resolved will raise a `ModuleNotFoundError` 1427 | at runtime. 1428 | 1429 | ### Examples 1430 | ```python 1431 | import foo # ModuleNotFoundError: No module named 'foo' 1432 | ``` 1433 | 1434 | ### Links 1435 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-import) 1436 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1292) 1437 |
1444 |
1462 |
1463 | ## `unsupported-bool-conversion`
1464 |
1465 | **Default level**: error
1466 |
1467 | detects references to names that are not defined
1445 | 1446 | ### What it does 1447 | Checks for references to names that are not defined. 1448 | 1449 | ### Why is this bad? 1450 | Using an undefined variable will raise a `NameError` at runtime. 1451 | 1452 | ### Example 1453 | 1454 | ```python 1455 | print(x) # NameError: name 'x' is not defined 1456 | ``` 1457 | 1458 | ### Links 1459 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-reference) 1460 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1311) 1461 |
1468 | detects boolean conversion where the object incorrectly implements
1469 |
1470 | ### What it does
1471 | Checks for bool conversions where the object doesn't correctly implement `__bool__`.
1472 |
1473 | ### Why is this bad?
1474 | If an exception is raised when you attempt to evaluate the truthiness of an object,
1475 | using the object in a boolean context will fail at runtime.
1476 |
1477 | ### Examples
1478 |
1479 | ```python
1480 | class NotBoolable:
1481 | __bool__ = None
1482 |
1483 | b1 = NotBoolable()
1484 | b2 = NotBoolable()
1485 |
1486 | if b1: # exception raised here
1487 | pass
1488 |
1489 | b1 and b2 # exception raised here
1490 | not b1 # exception raised here
1491 | b1 < b2 < b1 # exception raised here
1492 | ```
1493 |
1494 | ### Links
1495 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-bool-conversion)
1496 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1004)
1497 |
1498 |
1499 | ## `unsupported-operator`
1500 |
1501 | **Default level**: error
1502 |
1503 | detects boolean conversion where the object incorrectly implements __bool__
1469 |
1470 | ### What it does
1471 | Checks for bool conversions where the object doesn't correctly implement `__bool__`.
1472 |
1473 | ### Why is this bad?
1474 | If an exception is raised when you attempt to evaluate the truthiness of an object,
1475 | using the object in a boolean context will fail at runtime.
1476 |
1477 | ### Examples
1478 |
1479 | ```python
1480 | class NotBoolable:
1481 | __bool__ = None
1482 |
1483 | b1 = NotBoolable()
1484 | b2 = NotBoolable()
1485 |
1486 | if b1: # exception raised here
1487 | pass
1488 |
1489 | b1 and b2 # exception raised here
1490 | not b1 # exception raised here
1491 | b1 < b2 < b1 # exception raised here
1492 | ```
1493 |
1494 | ### Links
1495 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-bool-conversion)
1496 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1004)
1497 |
1504 |
1525 |
1526 | ## `zero-stepsize-in-slice`
1527 |
1528 | **Default level**: error
1529 |
1530 | detects binary, unary, or comparison expressions where the operands don't support the operator
1505 | 1506 | ### What it does 1507 | Checks for binary expressions, comparisons, and unary expressions where 1508 | the operands don't support the operator. 1509 | 1510 | ### Why is this bad? 1511 | Attempting to use an unsupported operator will raise a `TypeError` at 1512 | runtime. 1513 | 1514 | ### Examples 1515 | ```python 1516 | class A: ... 1517 | 1518 | A() + A() # TypeError: unsupported operand type(s) for +: 'A' and 'A' 1519 | ``` 1520 | 1521 | ### Links 1522 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-operator) 1523 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1330) 1524 |
1531 |
1549 |
1550 | ## `invalid-ignore-comment`
1551 |
1552 | **Default level**: warn
1553 |
1554 | detects a slice step size of zero
1532 | 1533 | ### What it does 1534 | Checks for step size 0 in slices. 1535 | 1536 | ### Why is this bad? 1537 | A slice with a step size of zero will raise a `ValueError` at runtime. 1538 | 1539 | ### Examples 1540 | ```python 1541 | l = list(range(10)) 1542 | l[1:10:0] # ValueError: slice step cannot be zero 1543 | ``` 1544 | 1545 | ### Links 1546 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20zero-stepsize-in-slice) 1547 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1352) 1548 |
1555 |
1578 |
1579 | ## `possibly-unbound-attribute`
1580 |
1581 | **Default level**: warn
1582 |
1583 | detects ignore comments that use invalid syntax
1556 | 1557 | ### What it does 1558 | Checks for `type: ignore` and `ty: ignore` comments that are syntactically incorrect. 1559 | 1560 | ### Why is this bad? 1561 | A syntactically incorrect ignore comment is probably a mistake and is useless. 1562 | 1563 | ### Examples 1564 | ```py 1565 | a = 20 / 0 # type: ignoree 1566 | ``` 1567 | 1568 | Use instead: 1569 | 1570 | ```py 1571 | a = 20 / 0 # type: ignore 1572 | ``` 1573 | 1574 | ### Links 1575 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-ignore-comment) 1576 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L65) 1577 |
1584 |
1605 |
1606 | ## `possibly-unbound-implicit-call`
1607 |
1608 | **Default level**: warn
1609 |
1610 | detects references to possibly unbound attributes
1585 | 1586 | ### What it does 1587 | Checks for possibly unbound attributes. 1588 | 1589 | ### Why is this bad? 1590 | Attempting to access an unbound attribute will raise an `AttributeError` at runtime. 1591 | 1592 | ### Examples 1593 | ```python 1594 | class A: 1595 | if b: 1596 | c = 0 1597 | 1598 | A.c # AttributeError: type object 'A' has no attribute 'c' 1599 | ``` 1600 | 1601 | ### Links 1602 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-unbound-attribute) 1603 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1056) 1604 |
1611 |
1636 |
1637 | ## `possibly-unbound-import`
1638 |
1639 | **Default level**: warn
1640 |
1641 | detects implicit calls to possibly unbound methods
1612 | 1613 | ### What it does 1614 | Checks for implicit calls to possibly unbound methods. 1615 | 1616 | ### Why is this bad? 1617 | Expressions such as `x[y]` and `x * y` call methods 1618 | under the hood (`__getitem__` and `__mul__` respectively). 1619 | Calling an unbound method will raise an `AttributeError` at runtime. 1620 | 1621 | ### Examples 1622 | ```python 1623 | import datetime 1624 | 1625 | class A: 1626 | if datetime.date.today().weekday() != 6: 1627 | def __getitem__(self, v): ... 1628 | 1629 | A()[0] # TypeError: 'A' object is not subscriptable 1630 | ``` 1631 | 1632 | ### Links 1633 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-unbound-implicit-call) 1634 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L109) 1635 |
1642 |
1667 |
1668 | ## `redundant-cast`
1669 |
1670 | **Default level**: warn
1671 |
1672 | detects possibly unbound imports
1643 | 1644 | ### What it does 1645 | Checks for imports of symbols that may be unbound. 1646 | 1647 | ### Why is this bad? 1648 | Importing an unbound module or name will raise a `ModuleNotFoundError` 1649 | or `ImportError` at runtime. 1650 | 1651 | ### Examples 1652 | ```python 1653 | ## module.py 1654 | import datetime 1655 | 1656 | if datetime.date.today().weekday() != 6: 1657 | a = 1 1658 | 1659 | ## main.py 1660 | from module import a # ImportError: cannot import name 'a' from 'module' 1661 | ``` 1662 | 1663 | ### Links 1664 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-unbound-import) 1665 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1078) 1666 |
1673 | detects redundant
1674 |
1675 | ### What it does
1676 | Detects redundant `cast` calls where the value already has the target type.
1677 |
1678 | ### Why is this bad?
1679 | These casts have no effect and can be removed.
1680 |
1681 | ### Example
1682 | ```python
1683 | def f() -> int:
1684 | return 10
1685 |
1686 | cast(int, f()) # Redundant
1687 | ```
1688 |
1689 | ### Links
1690 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20redundant-cast)
1691 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1423)
1692 |
1693 |
1694 | ## `undefined-reveal`
1695 |
1696 | **Default level**: warn
1697 |
1698 | detects redundant cast calls
1674 |
1675 | ### What it does
1676 | Detects redundant `cast` calls where the value already has the target type.
1677 |
1678 | ### Why is this bad?
1679 | These casts have no effect and can be removed.
1680 |
1681 | ### Example
1682 | ```python
1683 | def f() -> int:
1684 | return 10
1685 |
1686 | cast(int, f()) # Redundant
1687 | ```
1688 |
1689 | ### Links
1690 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20redundant-cast)
1691 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1423)
1692 |
1699 | detects usages of
1700 |
1701 | ### What it does
1702 | Checks for calls to `reveal_type` without importing it.
1703 |
1704 | ### Why is this bad?
1705 | Using `reveal_type` without importing it will raise a `NameError` at runtime.
1706 |
1707 | ### Examples
1708 | ```python
1709 | reveal_type(1) # NameError: name 'reveal_type' is not defined
1710 | ```
1711 |
1712 | ### Links
1713 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20undefined-reveal)
1714 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1231)
1715 |
1716 |
1717 | ## `unknown-rule`
1718 |
1719 | **Default level**: warn
1720 |
1721 | detects usages of reveal_type without importing it
1700 |
1701 | ### What it does
1702 | Checks for calls to `reveal_type` without importing it.
1703 |
1704 | ### Why is this bad?
1705 | Using `reveal_type` without importing it will raise a `NameError` at runtime.
1706 |
1707 | ### Examples
1708 | ```python
1709 | reveal_type(1) # NameError: name 'reveal_type' is not defined
1710 | ```
1711 |
1712 | ### Links
1713 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20undefined-reveal)
1714 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1231)
1715 |
1722 | detects
1723 |
1724 | ### What it does
1725 | Checks for `ty: ignore[code]` where `code` isn't a known lint rule.
1726 |
1727 | ### Why is this bad?
1728 | A `ty: ignore[code]` directive with a `code` that doesn't match
1729 | any known rule will not suppress any type errors, and is probably a mistake.
1730 |
1731 | ### Examples
1732 | ```py
1733 | a = 20 / 0 # ty: ignore[division-by-zer]
1734 | ```
1735 |
1736 | Use instead:
1737 |
1738 | ```py
1739 | a = 20 / 0 # ty: ignore[division-by-zero]
1740 | ```
1741 |
1742 | ### Links
1743 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unknown-rule)
1744 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L40)
1745 |
1746 |
1747 | ## `unsupported-base`
1748 |
1749 | **Default level**: warn
1750 |
1751 | detects ty: ignore comments that reference unknown rules
1723 |
1724 | ### What it does
1725 | Checks for `ty: ignore[code]` where `code` isn't a known lint rule.
1726 |
1727 | ### Why is this bad?
1728 | A `ty: ignore[code]` directive with a `code` that doesn't match
1729 | any known rule will not suppress any type errors, and is probably a mistake.
1730 |
1731 | ### Examples
1732 | ```py
1733 | a = 20 / 0 # ty: ignore[division-by-zer]
1734 | ```
1735 |
1736 | Use instead:
1737 |
1738 | ```py
1739 | a = 20 / 0 # ty: ignore[division-by-zero]
1740 | ```
1741 |
1742 | ### Links
1743 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unknown-rule)
1744 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L40)
1745 |
1752 |
1784 |
1785 | ## `division-by-zero`
1786 |
1787 | **Default level**: ignore
1788 |
1789 | detects class bases that are unsupported as ty could not feasibly calculate the class's MRO
1753 | 1754 | ### What it does 1755 | Checks for class definitions that have bases which are unsupported by ty. 1756 | 1757 | ### Why is this bad? 1758 | If a class has a base that is an instance of a complex type such as a union type, 1759 | ty will not be able to resolve the [method resolution order] (MRO) for the class. 1760 | This will lead to an inferior understanding of your codebase and unpredictable 1761 | type-checking behavior. 1762 | 1763 | ### Examples 1764 | ```python 1765 | import datetime 1766 | 1767 | class A: ... 1768 | class B: ... 1769 | 1770 | if datetime.date.today().weekday() != 6: 1771 | C = A 1772 | else: 1773 | C = B 1774 | 1775 | class D(C): ... # error: [unsupported-base] 1776 | ``` 1777 | 1778 | [method resolution order]: https://docs.python.org/3/glossary.html#term-method-resolution-order 1779 | 1780 | ### Links 1781 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-base) 1782 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L487) 1783 |
1790 |
1807 |
1808 | ## `possibly-unresolved-reference`
1809 |
1810 | **Default level**: ignore
1811 |
1812 | detects division by zero
1791 | 1792 | ### What it does 1793 | It detects division by zero. 1794 | 1795 | ### Why is this bad? 1796 | Dividing by zero raises a `ZeroDivisionError` at runtime. 1797 | 1798 | ### Examples 1799 | ```python 1800 | 5 / 0 1801 | ``` 1802 | 1803 | ### Links 1804 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20division-by-zero) 1805 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L238) 1806 |
1813 |
1834 |
1835 | ## `unused-ignore-comment`
1836 |
1837 | **Default level**: ignore
1838 |
1839 | detects references to possibly undefined names
1814 | 1815 | ### What it does 1816 | Checks for references to names that are possibly not defined. 1817 | 1818 | ### Why is this bad? 1819 | Using an undefined variable will raise a `NameError` at runtime. 1820 | 1821 | ### Example 1822 | 1823 | ```python 1824 | for i in range(0): 1825 | x = i 1826 | 1827 | print(x) # NameError: name 'x' is not defined 1828 | ``` 1829 | 1830 | ### Links 1831 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-unresolved-reference) 1832 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1104) 1833 |
1840 | detects unused
1841 |
1842 | ### What it does
1843 | Checks for `type: ignore` or `ty: ignore` directives that are no longer applicable.
1844 |
1845 | ### Why is this bad?
1846 | A `type: ignore` directive that no longer matches any diagnostic violations is likely
1847 | included by mistake, and should be removed to avoid confusion.
1848 |
1849 | ### Examples
1850 | ```py
1851 | a = 20 / 2 # ty: ignore[division-by-zero]
1852 | ```
1853 |
1854 | Use instead:
1855 |
1856 | ```py
1857 | a = 20 / 2
1858 | ```
1859 |
1860 | ### Links
1861 | * [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unused-ignore-comment)
1862 | * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L15)
1863 |
1864 |
1865 |
--------------------------------------------------------------------------------
/pyproject.toml:
--------------------------------------------------------------------------------
1 | [project]
2 | name = "ty"
3 | version = "0.0.1a7"
4 | requires-python = ">=3.8"
5 | dependencies = []
6 | description = "An extremely fast Python type checker, written in Rust."
7 | readme = "README.md"
8 | authors = [{ name = "Astral Software Inc.", email = "hey@astral.sh" }]
9 | keywords = ["ty", "typing", "analysis", "check"]
10 | classifiers = [
11 | "Development Status :: 3 - Alpha",
12 | "Environment :: Console",
13 | "Intended Audience :: Developers",
14 | "Operating System :: OS Independent",
15 | "License :: OSI Approved :: MIT License",
16 | "Programming Language :: Python",
17 | "Programming Language :: Python :: 3.8",
18 | "Programming Language :: Python :: 3.9",
19 | "Programming Language :: Python :: 3.10",
20 | "Programming Language :: Python :: 3.11",
21 | "Programming Language :: Python :: 3.12",
22 | "Programming Language :: Python :: 3.13",
23 | "Programming Language :: Python :: 3 :: Only",
24 | "Programming Language :: Rust",
25 | "Topic :: Software Development :: Quality Assurance",
26 | "Topic :: Software Development :: Testing",
27 | "Topic :: Software Development :: Libraries",
28 | "Topic :: Software Development :: Libraries :: Python Modules",
29 | ]
30 |
31 | [project.urls]
32 | Repository = "https://github.com/astral-sh/ty"
33 | Changelog = "https://github.com/astral-sh/ty/blob/main/CHANGELOG.md"
34 | Releases = "https://github.com/astral-sh/ty/releases"
35 | Discord = "https://discord.gg/astral-sh"
36 |
37 | [build-system]
38 | requires = ["maturin>=1.0,<2.0"]
39 | build-backend = "maturin"
40 |
41 | [dependency-groups]
42 | release = ["rooster-blue"]
43 |
44 | [tool.uv]
45 | cache-keys = [
46 | { file = "pyproject.toml" },
47 | { file = "dist-workspace.toml" },
48 | { file = "ruff/Cargo.toml" },
49 | { file = "ruff/Cargo.lock" },
50 | { file = "**/*.rs" },
51 | ]
52 |
53 | [tool.ruff]
54 | extend-exclude = ["ruff"]
55 |
56 | [tool.ruff.lint]
57 | select = [
58 | "E", # pycodestyle (error)
59 | "F", # pyflakes
60 | "B", # bugbear
61 | "B9",
62 | "C4", # flake8-comprehensions
63 | "SIM", # flake8-simplify
64 | "I", # isort
65 | "UP", # pyupgrade
66 | "PIE", # flake8-pie
67 | "PGH", # pygrep-hooks
68 | "PYI", # flake8-pyi
69 | "RUF",
70 | ]
71 |
72 | ignore = [
73 | # only relevant if you run a script with `python -0`,
74 | # which seems unlikely for any of the scripts in this repo
75 | "B011",
76 | # Leave it to the formatter to split long lines and
77 | # the judgement of all of us.
78 | "E501",
79 | ]
80 |
81 | [tool.ruff.lint.isort]
82 | required-imports = ["from __future__ import annotations"]
83 |
84 |
85 | [tool.uv.sources]
86 | rooster-blue = { git = "https://github.com/zanieb/rooster", rev = "cf27242" }
87 |
88 | [tool.maturin]
89 | bindings = "bin"
90 | manifest-path = "ruff/crates/ty/Cargo.toml"
91 | module-name = "ty"
92 | python-source = "python"
93 | strip = true
94 | include = [
95 | { path = "dist-workspace.toml", format = [
96 | "sdist",
97 | ] },
98 | { path = "LICENSE", format = "sdist" },
99 | ]
100 |
101 | [tool.rooster]
102 | version-files = [
103 | "pyproject.toml",
104 | { path = "dist-workspace.toml", field = "workspace.version", format = "cargo" },
105 | ]
106 | submodules = ["ruff"]
107 | require-labels = [{ submodule = "ruff", labels = ["ty"] }]
108 | ignore-labels = ["internal", "testing"]
109 | version-format = "cargo"
110 | default-bump-type = "pre"
111 | trim-title-prefixes = ["[ty]"]
112 |
113 | changelog_sections.breaking = "Breaking changes"
114 | changelog_sections.preview = "Preview features"
115 | changelog_sections.bug = "Bug fixes"
116 | changelog_sections.server = "Server"
117 | changelog_sections.cli = "CLI"
118 | changelog_sections.configuration = "Configuration"
119 | changelog_sections.documentation = "Documentation"
120 |
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/python/ty/__init__.py:
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/python/ty/__main__.py:
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1 | from __future__ import annotations
2 |
3 | import os
4 | import sys
5 | import sysconfig
6 |
7 |
8 | def find_ty_bin() -> str:
9 | """Return the ty binary path."""
10 |
11 | ty_exe = "ty" + sysconfig.get_config_var("EXE")
12 |
13 | scripts_path = os.path.join(sysconfig.get_path("scripts"), ty_exe)
14 | if os.path.isfile(scripts_path):
15 | return scripts_path
16 |
17 | if sys.version_info >= (3, 10):
18 | user_scheme = sysconfig.get_preferred_scheme("user")
19 | elif os.name == "nt":
20 | user_scheme = "nt_user"
21 | elif sys.platform == "darwin" and sys._framework:
22 | user_scheme = "osx_framework_user"
23 | else:
24 | user_scheme = "posix_user"
25 |
26 | user_path = os.path.join(sysconfig.get_path("scripts", scheme=user_scheme), ty_exe)
27 | if os.path.isfile(user_path):
28 | return user_path
29 |
30 | # Search in `bin` adjacent to package root (as created by `pip install --target`).
31 | pkg_root = os.path.dirname(os.path.dirname(__file__))
32 | target_path = os.path.join(pkg_root, "bin", ty_exe)
33 | if os.path.isfile(target_path):
34 | return target_path
35 |
36 | # Search for pip-specific build environments.
37 | #
38 | # Expect to find ty in