├── .gitignore ├── LICENSE.txt ├── README.md ├── cmd └── cmd.go ├── go.mod ├── main.go └── test.go /.gitignore: -------------------------------------------------------------------------------- 1 | /.idea 2 | 3 | ### Go template 4 | # Binaries for programs and plugins 5 | *.exe 6 | *.exe~ 7 | *.dll 8 | *.so 9 | *.dylib 10 | 11 | # Test binary, built with `go test -c` 12 | *.test 13 | 14 | # Output of the go coverage tool, specifically when used with LiteIDE 15 | *.out 16 | 17 | # Dependency directories (remove the comment below to include it) 18 | # vendor/ 19 | 20 | -------------------------------------------------------------------------------- /LICENSE.txt: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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We also recommend that a 185 | file or class name and description of purpose be included on the 186 | same "printed page" as the copyright notice for easier 187 | identification within third-party archives. 188 | 189 | Copyright [yyyy] [name of copyright owner] 190 | 191 | Licensed under the Apache License, Version 2.0 (the "License"); 192 | you may not use this file except in compliance with the License. 193 | You may obtain a copy of the License at 194 | 195 | http://www.apache.org/licenses/LICENSE-2.0 196 | 197 | Unless required by applicable law or agreed to in writing, software 198 | distributed under the License is distributed on an "AS IS" BASIS, 199 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 200 | See the License for the specific language governing permissions and 201 | limitations under the License. 202 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # dont-interface 2 | 3 | ``` 4 | > go run main.go --file test.go 5 | Among your codebase, there are... 6 | 8 parameters declared in functions, 5 of them are evil! (40.00% typed) 7 | 5 values returned from functions, 3 of them are evil! (40.00% typed) 8 | 3 fields declared in structs, 2 of them are evil! (33.33% typed) 9 | 2 values declared, 1 of them are evil! (50.00% typed) 10 | 3 type aliases introduced, 1 of them are evil! (66.67% typed) 11 | Overall, 42.86% of your types are strictly typed (not interface{}). 12 | ``` 13 | 14 | `dont-interface` calculates how many `interface{}` are declared or used in: 15 | 16 | - function parameters, e.g. `i1 interface{}, i2 []interface{}, i3 ...interface{}` 17 | - function return values, e.g. `(interface{}, string)` 18 | - struct fields, e.g. `i interface{}` 19 | - value declarations, e.g. `var i interface{}` 20 | - type aliases, e.g. `type NotInterface interface{}`. Note that `type I1 interface{ test1() }` is _not_ a type alias. 21 | 22 | This tiny snippet is partially inspired by Section 4.1.1 23 | of [LLVM: A Compilation Framework for Lifelong Program Analysis & Transformation](https://doi.org/10.1109/CGO.2004.1281665) 24 | , where the authors investigated to what extent is the LLVM's type speculation correct (and I know this paper have 25 | nothing to do with structural typing). 26 | 27 | ### Usage 28 | 29 | ``` 30 | > go install github.com/Ray-Eldath/dont-interface 31 | > dont-interface --file test.go --file main.go 32 | ``` 33 | 34 | ### The Last Thing... 35 | 36 | > [Don't `interface{}`!](https://youtu.be/yWeuUwpEQfs) 37 | > 38 | > :wink: 39 | -------------------------------------------------------------------------------- /cmd/cmd.go: -------------------------------------------------------------------------------- 1 | package cmd 2 | 3 | import ( 4 | "go/ast" 5 | "go/parser" 6 | "go/token" 7 | "path/filepath" 8 | ) 9 | 10 | type Visitor struct { 11 | TotalParams int 12 | EvilParams int 13 | 14 | TotalResults int 15 | EvilResults int 16 | 17 | TotalValueDecl int 18 | EvilValueDecl int 19 | 20 | TotalTypeAlias int 21 | EvilTypeAlias int 22 | 23 | TotalStructField int 24 | EvilStructField int 25 | } 26 | 27 | func (v *Visitor) Visit(node ast.Node) ast.Visitor { 28 | switch n := node.(type) { 29 | case *ast.FuncType: 30 | if n.Params != nil { 31 | v.TotalParams += n.Params.NumFields() 32 | for _, param := range n.Params.List { 33 | if checkIfEvil(param) { 34 | v.EvilParams += 1 35 | } 36 | if ellipsis, ok := param.Type.(*ast.Ellipsis); ok { 37 | if _, ok = ellipsis.Elt.(*ast.InterfaceType); ok { 38 | v.EvilParams += 1 39 | } 40 | } 41 | } 42 | } 43 | if n.Results != nil { 44 | v.TotalResults += n.Results.NumFields() 45 | for _, result := range n.Results.List { 46 | if checkIfEvil(result) { 47 | v.EvilResults += 1 48 | } 49 | } 50 | } 51 | case *ast.ValueSpec: 52 | v.TotalValueDecl += 1 53 | if _, ok := n.Type.(*ast.InterfaceType); ok { 54 | v.EvilValueDecl += 1 55 | } 56 | case *ast.TypeSpec: 57 | switch nn := n.Type.(type) { 58 | case *ast.InterfaceType: 59 | if nn.Methods == nil || nn.Methods.NumFields() <= 0 { 60 | v.TotalTypeAlias += 1 61 | v.EvilTypeAlias += 1 62 | } 63 | case *ast.StructType: 64 | if nn.Fields == nil || nn.Fields.NumFields() <= 0 { 65 | v.TotalTypeAlias += 1 66 | } 67 | default: 68 | v.TotalTypeAlias += 1 69 | } 70 | case *ast.StructType: 71 | fields := n.Fields 72 | if fields != nil { 73 | v.TotalStructField += fields.NumFields() 74 | for _, field := range fields.List { 75 | if checkIfEvil(field) { 76 | v.EvilStructField += 1 77 | } 78 | } 79 | } 80 | } 81 | return v 82 | } 83 | 84 | func checkIfEvil(field *ast.Field) bool { 85 | if field == nil { 86 | return false 87 | } 88 | switch f := field.Type.(type) { 89 | case *ast.InterfaceType: 90 | return true 91 | case *ast.ArrayType: 92 | _, ok := f.Elt.(*ast.InterfaceType) 93 | return ok 94 | } 95 | return false 96 | } 97 | 98 | func Calculate(paths []string) (*Visitor, error) { 99 | fset := token.NewFileSet() 100 | visitor := &Visitor{} 101 | for _, path := range paths { 102 | p, _ := filepath.Abs(path) 103 | f, err := parser.ParseFile(fset, p, nil, parser.AllErrors) 104 | // ast.Print(fset, f) 105 | if err != nil { 106 | return nil, err 107 | } 108 | ast.Walk(visitor, f) 109 | } 110 | return visitor, nil 111 | } 112 | -------------------------------------------------------------------------------- /go.mod: -------------------------------------------------------------------------------- 1 | module github.com/Ray-Eldath/dont-interface 2 | 3 | go 1.16 4 | -------------------------------------------------------------------------------- /main.go: -------------------------------------------------------------------------------- 1 | package main 2 | 3 | import ( 4 | "flag" 5 | "fmt" 6 | "os" 7 | "reflect" 8 | "strings" 9 | 10 | "github.com/Ray-Eldath/dont-interface/cmd" 11 | ) 12 | 13 | type arrayFlags []string 14 | 15 | func (i *arrayFlags) String() string { return strings.Join(*i, " ") } 16 | func (i *arrayFlags) Set(value string) error { 17 | *i = append(*i, value) 18 | return nil 19 | } 20 | 21 | var filesFlag arrayFlags 22 | 23 | func main() { 24 | flag.Var(&filesFlag, "file", "A single file that you want to include. Set this multiple times if you have many files.") 25 | flag.Parse() 26 | if len(filesFlag) <= 0 { 27 | fmt.Println("Error: no file specified, check out --help for usage.") 28 | os.Exit(255) 29 | } 30 | 31 | r, err := cmd.Calculate(filesFlag) 32 | if err != nil { 33 | fmt.Printf("Error: %s\n", err) 34 | os.Exit(1) 35 | } 36 | 37 | fmt.Println("Among your codebase, there are...") 38 | fmt.Printf(" %d parameters declared in functions, %d of them are evil! (%s typed)\n", r.TotalParams, r.EvilParams, percentage(r.EvilResults, r.TotalResults)) 39 | fmt.Printf(" %d values returned from functions, %d of them are evil! (%s typed)\n", r.TotalResults, r.EvilResults, percentage(r.EvilResults, r.TotalResults)) 40 | fmt.Printf(" %d fields declared in structs, %d of them are evil! (%s typed)\n", r.TotalStructField, r.EvilStructField, percentage(r.EvilStructField, r.TotalStructField)) 41 | fmt.Printf(" %d values declared, %d of them are evil! (%s typed)\n", r.TotalValueDecl, r.EvilValueDecl, percentage(r.EvilValueDecl, r.TotalValueDecl)) 42 | fmt.Printf(" %d type aliases introduced, %d of them are evil! (%s typed)\n", r.TotalTypeAlias, r.EvilTypeAlias, percentage(r.EvilTypeAlias, r.TotalTypeAlias)) 43 | fmt.Printf("Overall, %s of your types are strictly typed (not interface{}).", sum(*r)) 44 | } 45 | 46 | func sum(visitor cmd.Visitor) string { 47 | t := reflect.TypeOf(visitor) 48 | v := reflect.ValueOf(visitor) 49 | var ( 50 | total int 51 | evil int 52 | ) 53 | for i := 0; i < t.NumField(); i++ { 54 | field := t.Field(i) 55 | name := field.Name 56 | if strings.HasPrefix(name, "Total") { 57 | total += int(v.Field(i).Int()) 58 | } else if strings.HasPrefix(name, "Evil") { 59 | evil += int(v.Field(i).Int()) 60 | } 61 | } 62 | return percentage(evil, total) 63 | } 64 | 65 | func percentage(u int, d int) string { 66 | if d == 0 { 67 | return "100%" 68 | } 69 | return fmt.Sprintf("%.2f%%", (float64(d-u)/float64(d))*100) 70 | } 71 | -------------------------------------------------------------------------------- /test.go: -------------------------------------------------------------------------------- 1 | package main 2 | 3 | func test(inter1 interface{}, inter2 ...interface{}) (interface{}, string) { 4 | var inter3 interface{} 5 | var s string 6 | 7 | return inter3, s 8 | } 9 | 10 | func test2(str string, int int32, inter4 []interface{}) []interface{} { return nil } 11 | 12 | type test3 struct { 13 | i int 14 | inter5 interface{} 15 | inter6 []interface{} 16 | } 17 | 18 | type I interface { 19 | test4(f float64, inter7 interface{}, inter8 ...interface{}) (iii interface{}, sss string) 20 | } 21 | 22 | type T1 interface{} 23 | type T2 string 24 | type T3 struct{} 25 | type I1 interface{ test1() } 26 | --------------------------------------------------------------------------------