├── .github └── workflows │ └── node.js.yml ├── .gitignore ├── CODE_OF_CONDUCT.md ├── CONTRIBUTING.md ├── LICENSE ├── README.md ├── index.d.ts ├── index.js ├── index.test.js ├── package-lock.json ├── package.json ├── props.test.css └── props.test.empty.css /.github/workflows/node.js.yml: -------------------------------------------------------------------------------- 1 | name: Unit Tests 2 | on: [push, pull_request] 3 | 4 | jobs: 5 | build: 6 | runs-on: ubuntu-latest 7 | strategy: 8 | matrix: 9 | node-version: [14.x] 10 | steps: 11 | - uses: actions/checkout@v2 12 | - name: Use Node.js ${{ matrix.node-version }} 13 | uses: actions/setup-node@v2 14 | with: 15 | node-version: ${{ matrix.node-version }} 16 | cache: 'npm' 17 | - run: npm ci 18 | - run: npm test 19 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | coverage/ 2 | node_modules/ 3 | .DS_Store -------------------------------------------------------------------------------- /CODE_OF_CONDUCT.md: -------------------------------------------------------------------------------- 1 | # Contributor Covenant Code of Conduct 2 | 3 | ## Our Pledge 4 | 5 | In the interest of fostering an open and welcoming environment, we as contributors and maintainers pledge to making participation in our project and our community a harassment-free experience for everyone, regardless of age, body size, disability, ethnicity, sex characteristics, gender identity and expression, level of experience, education, socio-economic status, nationality, personal appearance, race, religion, or sexual identity and orientation. 6 | 7 | ## Our Standards 8 | 9 | Examples of behavior that contributes to creating a positive environment include: 10 | 11 | - Using welcoming and inclusive language 12 | - Being respectful of differing viewpoints and experiences 13 | - Gracefully accepting constructive criticism 14 | - Focusing on what is best for the community 15 | - Showing empathy towards other community members 16 | 17 | Examples of unacceptable behavior by participants include: 18 | 19 | - The use of sexualized language or imagery and unwelcome sexual attention or advances 20 | - Trolling, insulting/derogatory comments, and personal or political attacks 21 | - Public or private harassment 22 | - Publishing others' private information, such as a physical or electronic address, without explicit permission 23 | - Other conduct which could reasonably be considered inappropriate in a professional setting 24 | 25 | ## Our Responsibilities 26 | 27 | Project maintainers are responsible for clarifying the standards of acceptable behavior and are expected to take appropriate and fair corrective action in response to any instances of unacceptable behavior. 28 | 29 | Project maintainers have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, or to ban temporarily or permanently any contributor for other behaviors that they deem inappropriate, threatening, offensive, or harmful. 30 | 31 | ## Scope 32 | 33 | This Code of Conduct applies both within project spaces and in public spaces when an individual is representing the project or its community. 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We also recommend that a 186 | file or class name and description of purpose be included on the 187 | same "printed page" as the copyright notice for easier 188 | identification within third-party archives. 189 | 190 | Copyright [yyyy] [name of copyright owner] 191 | 192 | Licensed under the Apache License, Version 2.0 (the "License"); 193 | you may not use this file except in compliance with the License. 194 | You may obtain a copy of the License at 195 | 196 | http://www.apache.org/licenses/LICENSE-2.0 197 | 198 | Unless required by applicable law or agreed to in writing, software 199 | distributed under the License is distributed on an "AS IS" BASIS, 200 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 201 | See the License for the specific language governing permissions and 202 | limitations under the License. 203 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # PostCSS (Just In Time) Props 2 | 3 | > Only ship used variables! A CSS custom property helper based on PostCSS 4 | 5 | [![Version](https://img.shields.io/npm/v/postcss-jit-props)](https://www.npmjs.com/package/postcss-jit-props) 6 | [![postcss compatibility](https://img.shields.io/npm/dependency-version/postcss-jit-props/peer/postcss)](https://postcss.org/) 7 | [![Unit Tests](https://github.com/GoogleChromeLabs/postcss-jit-props/actions/workflows/node.js.yml/badge.svg)](https://github.com/GoogleChromeLabs/postcss-jit-props/actions/workflows/node.js.yml) 8 | 9 |
10 | 11 | `postcss-jit-props` watches for CSS variables and ensures a value entry exists in the stylesheet. [Try in browser](https://stackblitz.com/edit/jit-open-props?file=postcss.config.js) 12 | 13 | This lets you **provide a huge pool of properties** for development and design, and rather than try and purge unused variables, **only adds what was used**. 14 | 15 |
16 | 17 | ## Example 18 | 19 | CSS Before / During Development: 20 | ```css 21 | .foo { 22 | color: var(--brand-1); 23 | padding: var(--size-1) var(--size-2); 24 | margin-block-start: var(--size-2); 25 | animation: var(--fade-in); 26 | } 27 | 28 | @media (--dark) { 29 | .foo { 30 | color: white; 31 | } 32 | } 33 | ``` 34 | 35 | CSS After / Result of Plugin: 36 | ```diff 37 | + @custom-media --dark (prefers-color-scheme: dark); 38 | 39 | + :root { 40 | + --brand-1: #81A1C1; 41 | + --size-1: 1rem; 42 | + --size-2: 2rem; 43 | + --fade-in: fade-in .5s ease; 44 | + } 45 | 46 | .foo { 47 | color: var(--brand-1); 48 | padding: var(--size-1) var(--size-2); 49 | margin-block-start: var(--size-2); 50 | animation: var(--fade-in); 51 | } 52 | 53 | @media (--dark) { 54 | .foo { 55 | color: white; 56 | } 57 | } 58 | 59 | + @keyframes fade-in { 60 | + to { opacity: 1; } 61 | + } 62 | ``` 63 | 64 |
65 | 66 | ## Usage 67 | 68 | **Step 1:** Install plugin: 69 | 70 | ```sh 71 | npm install --save-dev postcss-jit-props 72 | ``` 73 | 74 |
75 | 76 | **Step 2:** Add the plugin to plugins in `postcss.config.js` and **pass it your props (CSS || JS || JSON)**. 77 | 78 | Pass JS objects: 79 | ```js 80 | module.exports = { 81 | plugins: [ 82 | require('postcss-jit-props')({ 83 | '--brand-1': '#81A1C1', 84 | '--size-1': '1rem', 85 | '--size-2': '2rem', 86 | '--fade-in': 'fade-in .5s ease', 87 | '--fade-in-@': '@keyframes fade-in {to { opacity: 1 }}', 88 | '--dark': '@custom-media --dark (prefers-color-scheme: dark);', 89 | '--text': 'white', 90 | '--text-@media:dark': 'black', 91 | }), 92 | require('autoprefixer'), 93 | ] 94 | } 95 | ``` 96 | 97 | or pass CSS files 98 | 99 | ```js 100 | module.exports = { 101 | plugins: [ 102 | require('postcss-jit-props')({files: ['./props.css']}), 103 | require('autoprefixer'), 104 | ] 105 | } 106 | ``` 107 | 108 | or JSON ✨ 109 | 110 | > Javascript and JSON must use the `-@` suffix on their custom property name in order for jit-props to find associated `@keyframes` 111 | 112 | Configure where the selector the props are pushed to. Some CSS Module environments, for example, don't want the props in `:root`, so we can configure the plugin to push them where it's acceptable for the environment, like `:global`: 113 | 114 | ```js 115 | module.exports = { 116 | plugins: [ 117 | require('postcss-jit-props')({ 118 | ...MyProps, 119 | custom_selector: ':global' 120 | }), 121 | require('autoprefixer'), 122 | ] 123 | } 124 | ``` 125 | 126 | Configure the `@layer` the props are pushed to. : 127 | 128 | ```js 129 | module.exports = { 130 | plugins: [ 131 | require('postcss-jit-props')({ 132 | ...MyProps, 133 | layer: 'design.system' 134 | }), 135 | require('autoprefixer'), 136 | ] 137 | } 138 | ``` 139 | -------------------------------------------------------------------------------- /index.d.ts: -------------------------------------------------------------------------------- 1 | import { PluginCreator } from "postcss"; 2 | 3 | export interface Options { 4 | /** 5 | * Wraps the entire rule inside `@layer` syntax. 6 | */ 7 | layer?: string; 8 | 9 | /** 10 | * Where to search for css props, globbing allowed. 11 | */ 12 | files?: string[]; 13 | 14 | /** 15 | * Selector where the props are pushed to instead of `:root`. 16 | */ 17 | custom_selector?: string; 18 | } 19 | 20 | type Props = Record; 21 | 22 | export type PostcssJitPropsOptions = Options & Props; 23 | declare const postcssJitProps: PluginCreator; 24 | 25 | export default postcssJitProps; 26 | -------------------------------------------------------------------------------- /index.js: -------------------------------------------------------------------------------- 1 | /** 2 | * Copyright 2020 Google Inc. All Rights Reserved. 3 | * Licensed under the Apache License, Version 2.0 (the "License"); 4 | * you may not use this file except in compliance with the License. 5 | * You may obtain a copy of the License at 6 | * http://www.apache.org/licenses/LICENSE-2.0 7 | * Unless required by applicable law or agreed to in writing, software 8 | * distributed under the License is distributed on an "AS IS" BASIS, 9 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 10 | * See the License for the specific language governing permissions and 11 | * limitations under the License. 12 | */ 13 | 14 | const fs = require('fs'); 15 | const crypto = require('crypto'); 16 | 17 | const glob = require('tiny-glob/sync'); 18 | 19 | const processed = new WeakSet(); 20 | 21 | const getAdaptivePropSelector = (selector) => { 22 | return (prop) => { 23 | if (!selector) { 24 | return `${prop}-@media:dark` 25 | } 26 | 27 | return `${prop}${selector}` 28 | } 29 | } 30 | 31 | /** @type { import('postcss').PluginCreator }*/ 32 | module.exports = (options) => { 33 | const { 34 | files, 35 | adaptive_prop_selector, 36 | custom_selector, 37 | custom_selector_dark, 38 | layer, ...props 39 | } = options 40 | 41 | const FilePropsCache = new Map(); 42 | 43 | return { 44 | postcssPlugin: 'postcss-jit-props', 45 | prepare() { 46 | const UserProps = { ...props } 47 | 48 | const STATE = { 49 | mapped: null, // track prepended props 50 | mapped_dark: null, // track dark mode prepended props 51 | 52 | target_layer: null, // layer for props 53 | target_rule: null, // :root for props 54 | target_rule_dark: null, // :root for dark props 55 | target_ss: null, // stylesheet for keyframes/MQs 56 | target_media_dark: null, // dark media query props 57 | } 58 | 59 | const adaptivePropSelector = getAdaptivePropSelector(adaptive_prop_selector) 60 | 61 | return { 62 | Once(node, { parse, result, Rule, AtRule }) { 63 | let target_selector = custom_selector || ':root' 64 | let target_selector_dark = custom_selector_dark || custom_selector || ':root' 65 | 66 | if (!files && !Object.keys(props).length) { 67 | return console.warn('postcss-jit-props: Variable source(s) not passed.') 68 | } 69 | 70 | if (files?.length) { 71 | 72 | const globs = files 73 | .map((file) => glob(file)) 74 | .reduce((flattenedFileList, files) => flattenedFileList.concat(files), []) 75 | 76 | globs.map(file => { 77 | result.messages.push({ 78 | type: 'dependency', 79 | plugin: 'postcss-jit-props', 80 | file: file, 81 | parent: node.source?.input?.file, 82 | }); 83 | 84 | let data = fs.readFileSync(file, 'utf8') 85 | 86 | const hashSum = crypto.createHash('sha256') 87 | hashSum.update(file) 88 | hashSum.update(data) 89 | const fileCacheKey = hashSum.digest('hex') 90 | 91 | if (FilePropsCache.has(fileCacheKey)) { 92 | const fileProps = FilePropsCache.get(fileCacheKey) 93 | for (const [key, value] of fileProps) { 94 | UserProps[key] = value 95 | } 96 | 97 | return 98 | } 99 | 100 | const fileProps = new Map() 101 | FilePropsCache.set(fileCacheKey, fileProps) 102 | 103 | let dependencyResult = parse(data, { from: file }) 104 | 105 | dependencyResult.walkDecls(decl => { 106 | if (!decl.variable) return 107 | UserProps[decl.prop] = decl.value 108 | fileProps.set(decl.prop, decl.value) 109 | }) 110 | 111 | dependencyResult.walkAtRules(atrule => { 112 | if (atrule.name === 'custom-media') { 113 | let media = atrule.params.slice(0, atrule.params.indexOf(' ')) 114 | UserProps[media] = `@custom-media ${atrule.params};` 115 | fileProps.set(media, `@custom-media ${atrule.params};`) 116 | } 117 | else if (atrule.name === 'keyframes') { 118 | let keyframeName = `--${atrule.params}-@` 119 | let keyframes = atrule.source.input.css.slice(atrule.source.start.offset, atrule.source.end.offset + 1) 120 | UserProps[keyframeName] = keyframes 121 | fileProps.set(keyframeName, keyframes) 122 | } 123 | }) 124 | }) 125 | } 126 | 127 | STATE.mapped = new Set() 128 | STATE.mapped_dark = new Set() 129 | 130 | if (node.first) { 131 | STATE.target_rule = new Rule({ selector: target_selector, source: node.first.source }) 132 | STATE.target_rule_dark = new Rule({ selector: target_selector_dark, source: node.first.source }) 133 | STATE.target_media_dark = new AtRule({ name: 'media', params: '(prefers-color-scheme: dark)', source: node.first.source }) 134 | } 135 | 136 | if (layer && node.first) { 137 | STATE.target_layer = new AtRule({ name: 'layer', params: layer, source: node.first.source }) 138 | node.root().prepend(STATE.target_layer) 139 | STATE.target_ss = STATE.target_layer 140 | } 141 | else 142 | STATE.target_ss = node.root() 143 | }, 144 | 145 | AtRule: { 146 | media: (atrule, { parse }) => { 147 | // bail early if possible 148 | if (processed.has(atrule)) return 149 | 150 | // extract prop from atrule params 151 | let prop = atrule.params.replace(/[( )]+/g, ''); 152 | 153 | // bail if media prop already prepended 154 | if (STATE.mapped.has(prop)) return 155 | 156 | // create :root {} context just in time 157 | if (STATE.mapped.size === 0) 158 | STATE.target_ss.prepend(STATE.target_rule) 159 | 160 | // lookup prop value from pool 161 | let value = UserProps[prop] || null 162 | 163 | // warn if media prop not resolved 164 | if (!value) { 165 | return 166 | } 167 | 168 | // prepend the custom media 169 | const customMedia = parse(value).first 170 | customMedia.source = atrule.source 171 | STATE.target_ss.prepend(customMedia) 172 | 173 | // track work to prevent duplication 174 | processed.add(atrule) 175 | STATE.mapped.add(prop) 176 | } 177 | }, 178 | 179 | Declaration(node, { Declaration, parse }) { 180 | // bail early 181 | if (processed.has(node) || !node.value) return 182 | // console.log(node) 183 | let matches = node.value.match(/var\(\s*(--[\w\d-_]+)/g) 184 | 185 | if (!matches) return 186 | 187 | // create :root {} context just in time 188 | if (STATE.mapped.size === 0) 189 | STATE.target_ss.prepend(STATE.target_rule) 190 | 191 | let props = matches.map(v => v.replace('var(', '').trim()) 192 | 193 | for (let prop of props) { 194 | // bail prepending this prop if it's already been done 195 | if (STATE.mapped.has(prop)) continue 196 | 197 | // lookup prop from options object 198 | let value = UserProps[prop] || null 199 | 200 | // warn if props won't resolve from plugin 201 | if (!value) { 202 | continue 203 | } 204 | 205 | // create and append prop to :root 206 | let decl = new Declaration({ prop, value, source: node.source }) 207 | STATE.target_rule.append(decl) 208 | STATE.mapped.add(prop) 209 | 210 | // lookup keyframes for the prop and append if found 211 | let keyframes = UserProps[`${prop}-@`] 212 | if (keyframes) { 213 | const keyframesNode = parse(keyframes).first 214 | keyframesNode.source = node.source 215 | keyframesNode.walk((x) => x.source = node.source) 216 | STATE.target_ss.append(keyframesNode) 217 | } 218 | 219 | // lookup dark adaptive prop and append if found 220 | let adaptive = UserProps[adaptivePropSelector(prop)] 221 | if (adaptive && !STATE.mapped_dark.has(prop)) { 222 | // create @media ... { :root {} } context just in time 223 | if (STATE.mapped_dark.size === 0) { 224 | STATE.target_media_dark.append(STATE.target_rule_dark) 225 | STATE.target_ss.append(STATE.target_media_dark) 226 | } 227 | 228 | if (adaptive.includes('@keyframes')) { 229 | const adaptiveNode = parse(adaptive).first 230 | adaptiveNode.source = node.source 231 | adaptiveNode.walk((x) => x.source = node.source) 232 | STATE.target_media_dark.append(adaptiveNode) 233 | } 234 | else { 235 | // append adaptive prop definition to dark media query 236 | let darkdecl = new Declaration({ prop, value: adaptive, source: node.source }) 237 | STATE.target_rule_dark.append(darkdecl) 238 | STATE.mapped_dark.add(prop) 239 | } 240 | } 241 | 242 | // track work to prevent duplicative processing 243 | processed.add(node) 244 | } 245 | } 246 | } 247 | } 248 | } 249 | } 250 | 251 | module.exports.postcss = true 252 | -------------------------------------------------------------------------------- /index.test.js: -------------------------------------------------------------------------------- 1 | /** 2 | * Copyright 2020 Google Inc. All Rights Reserved. 3 | * Licensed under the Apache License, Version 2.0 (the "License"); 4 | * you may not use this file except in compliance with the License. 5 | * You may obtain a copy of the License at 6 | * http://www.apache.org/licenses/LICENSE-2.0 7 | * Unless required by applicable law or agreed to in writing, software 8 | * distributed under the License is distributed on an "AS IS" BASIS, 9 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 10 | * See the License for the specific language governing permissions and 11 | * limitations under the License. 12 | */ 13 | 14 | const postcss = require('postcss') 15 | const plugin = require('./') 16 | 17 | const MockProps = { 18 | '--red': '#f00', 19 | '--pink': '#ffc0cb', 20 | '--h': 200, 21 | '--s': '50%', 22 | '--l': '50%', 23 | '--size-1': '1rem', 24 | '--size-2': '2rem', 25 | '--fade-in': 'fade-in .5s ease', 26 | '--fade-in-@': '@keyframes fade-in {to { opacity: 1 }}', 27 | '--adaptive-fade': 'adaptive-fade .5s ease', 28 | '--adaptive-fade-@': '@keyframes adaptive-fade {to { background: white }}', 29 | '--adaptive-fade-@media:dark': '@keyframes adaptive-fade {to { background: black }}', 30 | '--dark': '@custom-media --dark (prefers-color-scheme: dark);', 31 | '--text': 'white', 32 | '--text-@media:dark': 'black', 33 | } 34 | 35 | const MockPropsWithCustomAdaptiveProp = { 36 | '--text': 'white', 37 | '--text-dark': 'black', 38 | } 39 | 40 | async function run (input, output, options = { }) { 41 | let result = await postcss([plugin(options)]).process(input, { from: 'input.css', to: 'output.css', map: { inline: false } }) 42 | expect(result.css.replace('\n/*# sourceMappingURL=output.css.map */', '')).toEqual(output) 43 | expect(result.warnings()).toHaveLength(0) 44 | 45 | if (options.files?.length) { 46 | expect(result.messages.filter(x => x.type === 'dependency')).toHaveLength(options.files?.length) 47 | } 48 | 49 | const map = result.map.toJSON() 50 | expect(map.sources).toEqual(['input.css']) 51 | } 52 | 53 | it('Can jit a single prop', async () => { 54 | await run( 55 | `a { 56 | color: var(--red); 57 | }`, 58 | `:root { 59 | --red: #f00; 60 | } 61 | a { 62 | color: var(--red); 63 | }`, 64 | MockProps 65 | ) 66 | }) 67 | 68 | it('Can jit a single prop with spaces', async () => { 69 | await run( 70 | `a { 71 | color: var( --red ); 72 | }`, 73 | `:root { 74 | --red: #f00; 75 | } 76 | a { 77 | color: var( --red ); 78 | }`, 79 | MockProps 80 | ) 81 | }) 82 | 83 | it('Can jit a single prop that has fallbacks', async () => { 84 | await run( 85 | `a { 86 | color: var(--red, hotpink); 87 | }`, 88 | `:root { 89 | --red: #f00; 90 | } 91 | a { 92 | color: var(--red, hotpink); 93 | }`, 94 | MockProps 95 | ) 96 | }) 97 | 98 | it('Can jit a single prop with spaces that has fallbacks', async () => { 99 | await run( 100 | `a { 101 | color: var( --red, hotpink); 102 | }`, 103 | `:root { 104 | --red: #f00; 105 | } 106 | a { 107 | color: var( --red, hotpink); 108 | }`, 109 | MockProps 110 | ) 111 | }) 112 | 113 | it('Can jit a single prop that has fallbacks and nested props', async () => { 114 | await run( 115 | `a { 116 | color: var(--red, var(--pink), hotpink); 117 | }`, 118 | `:root { 119 | --red: #f00; 120 | --pink: #ffc0cb; 121 | } 122 | a { 123 | color: var(--red, var(--pink), hotpink); 124 | }`, 125 | MockProps 126 | ) 127 | }) 128 | 129 | it('Can jit a single, undefined prop that has fallbacks and nested props', async () => { 130 | await run( 131 | `a { 132 | color: var(--orange, var(--pink), hotpink); 133 | }`, 134 | `:root { 135 | --pink: #ffc0cb; 136 | } 137 | a { 138 | color: var(--orange, var(--pink), hotpink); 139 | }`, 140 | MockProps 141 | ) 142 | }) 143 | 144 | 145 | it('Can jit a single prop with spaces that has fallbacks and nested props', async () => { 146 | await run( 147 | `a { 148 | color: var( --red, var( --pink ), hotpink); 149 | }`, 150 | `:root { 151 | --red: #f00; 152 | --pink: #ffc0cb; 153 | } 154 | a { 155 | color: var( --red, var( --pink ), hotpink); 156 | }`, 157 | MockProps 158 | ) 159 | }) 160 | 161 | it('Can jit multiple props', async () => { 162 | await run( 163 | `a { 164 | color: var(--red); 165 | border-color: var(--pink); 166 | padding-block-start: var( --size-1 ); 167 | }`, 168 | `:root { 169 | --red: #f00; 170 | --pink: #ffc0cb; 171 | --size-1: 1rem; 172 | } 173 | a { 174 | color: var(--red); 175 | border-color: var(--pink); 176 | padding-block-start: var( --size-1 ); 177 | }`, 178 | MockProps 179 | ) 180 | }) 181 | 182 | it('Can jit multiple props from shorthand', async () => { 183 | await run( 184 | `a { 185 | padding-block: var(--size-1) var( --size-2 ); 186 | }`, 187 | `:root { 188 | --size-1: 1rem; 189 | --size-2: 2rem; 190 | } 191 | a { 192 | padding-block: var(--size-1) var( --size-2 ); 193 | }`, 194 | MockProps 195 | ) 196 | }) 197 | 198 | it('Can jit props from inside functions', async () => { 199 | await run( 200 | `a { 201 | color: hsl(var(--h) var(--s) var( --l )); 202 | }`, 203 | `:root { 204 | --h: 200; 205 | --s: 50%; 206 | --l: 50%; 207 | } 208 | a { 209 | color: hsl(var(--h) var(--s) var( --l )); 210 | }`, 211 | MockProps 212 | ) 213 | }) 214 | 215 | it('Only adds a prop one time to :root', async () => { 216 | await run( 217 | `a { 218 | color: var(--red); 219 | border-color: var(--red ); 220 | }`, 221 | `:root { 222 | --red: #f00; 223 | } 224 | a { 225 | color: var(--red); 226 | border-color: var(--red ); 227 | }`, 228 | MockProps 229 | ) 230 | }) 231 | 232 | it('Can jit props into a layer', async () => { 233 | await run( 234 | `a { 235 | color: hsl(var(--h) var(--s) var( --l )); 236 | }`, 237 | `@layer test { 238 | :root { 239 | --h: 200; 240 | --s: 50%; 241 | --l: 50%; 242 | } 243 | } 244 | a { 245 | color: hsl(var(--h) var(--s) var( --l )); 246 | }`, 247 | { 248 | ... MockProps, 249 | layer: 'test', 250 | } 251 | ) 252 | }) 253 | 254 | it('Can jit a keyframe animation', async () => { 255 | await run( 256 | `a { 257 | animation: var(--fade-in); 258 | }`, 259 | `:root { 260 | --fade-in: fade-in .5s ease; 261 | }a { 262 | animation: var(--fade-in); 263 | }@keyframes fade-in {to { opacity: 1 }}`, 264 | MockProps 265 | ) 266 | }) 267 | 268 | it('Can jit an adaptive keyframe animation', async () => { 269 | await run( 270 | `a { 271 | animation: var(--adaptive-fade); 272 | }`, 273 | `:root { 274 | --adaptive-fade: adaptive-fade .5s ease; 275 | }a { 276 | animation: var(--adaptive-fade); 277 | }@keyframes adaptive-fade {to { background: white }}@media (prefers-color-scheme: dark) {:root {}@keyframes adaptive-fade {to { background: black }} 278 | }`, 279 | MockProps 280 | ) 281 | }) 282 | 283 | it('Can jit @custom-media', async () => { 284 | await run( 285 | `@media (--dark) { 286 | a { 287 | color: white; 288 | } 289 | }`, 290 | `@custom-media --dark (prefers-color-scheme: dark); 291 | :root{} 292 | @media (--dark) { 293 | a { 294 | color: white; 295 | } 296 | }`, 297 | MockProps 298 | ) 299 | }) 300 | 301 | it('Can jit @custom-media with spaces', async () => { 302 | await run( 303 | `@media ( --dark ) { 304 | a { 305 | color: white; 306 | } 307 | }`, 308 | `@custom-media --dark (prefers-color-scheme: dark); 309 | :root{} 310 | @media ( --dark ) { 311 | a { 312 | color: white; 313 | } 314 | }`, 315 | MockProps 316 | ) 317 | }) 318 | 319 | it('Can jit props from JSON', async () => { 320 | await run( 321 | `a { 322 | color: var(--red); 323 | border-color: var( --pink ); 324 | }`, 325 | `:root { 326 | --red: #f00; 327 | --pink: #ffc0cb; 328 | } 329 | a { 330 | color: var(--red); 331 | border-color: var( --pink ); 332 | }`, 333 | MockProps 334 | ) 335 | }) 336 | 337 | it('Can jit props from a CSS file', async () => { 338 | await run( 339 | `@media (--dark) { 340 | a { 341 | color: var(--red); 342 | border-color: var( --pink ); 343 | animation: var(--fade-in); 344 | } 345 | }`, 346 | `@custom-media --dark (prefers-color-scheme: dark); 347 | :root{ 348 | --red: #f00; 349 | --pink: #ffc0cb; 350 | --fade-in: fade-in .5s ease; 351 | } 352 | @media (--dark) { 353 | a { 354 | color: var(--red); 355 | border-color: var( --pink ); 356 | animation: var(--fade-in); 357 | } 358 | } 359 | @keyframes fade-in {to { opacity: 1 }}`, 360 | { files: ['./props.test.css']} 361 | ) 362 | }) 363 | 364 | it('Can jit props from a CSS file via glob', async () => { 365 | await run( 366 | `@media (--dark) { 367 | a { 368 | color: var(--red); 369 | border-color: var( --pink ); 370 | animation: var(--fade-in); 371 | } 372 | }`, 373 | `@custom-media --dark (prefers-color-scheme: dark); 374 | :root{ 375 | --red: #f00; 376 | --pink: #ffc0cb; 377 | --fade-in: fade-in .5s ease; 378 | } 379 | @media (--dark) { 380 | a { 381 | color: var(--red); 382 | border-color: var( --pink ); 383 | animation: var(--fade-in); 384 | } 385 | } 386 | @keyframes fade-in {to { opacity: 1 }}`, 387 | { files: ['./*.test.css']} 388 | ) 389 | }) 390 | 391 | it('Can fail without srcProps options gracefully', async () => { 392 | console.warn = jest.fn() 393 | await postcss([plugin({})]).process(``, { from: undefined }) 394 | 395 | expect(console.warn).toHaveBeenCalledWith('postcss-jit-props: Variable source(s) not passed.') 396 | }) 397 | 398 | it('Can jit props to a custom selector', async () => { 399 | await run( 400 | `a { 401 | color: var(--red); 402 | }`, 403 | `:global { 404 | --red: #f00; 405 | } 406 | a { 407 | color: var(--red); 408 | }`, 409 | { 410 | ... MockProps, 411 | custom_selector: ':global', 412 | } 413 | ) 414 | }) 415 | 416 | it('Can jit light and dark props to a custom selector', async () => { 417 | await run( 418 | `a { 419 | color: var(--text); 420 | }`, 421 | `:global { 422 | --text: white; 423 | } 424 | a { 425 | color: var(--text); 426 | } 427 | @media (prefers-color-scheme: dark) { 428 | :global { 429 | --text: black; 430 | } 431 | }`, 432 | { 433 | ... MockProps, 434 | custom_selector: ':global', 435 | } 436 | ) 437 | }) 438 | 439 | it('Can jit light & dark props to a custom selector for use with a client side switch', async () => { 440 | await run( 441 | `a { 442 | color: var(--text); 443 | }`, 444 | `.light { 445 | --text: white; 446 | } 447 | a { 448 | color: var(--text); 449 | } 450 | @media (prefers-color-scheme: dark) { 451 | .dark { 452 | --text: black; 453 | } 454 | }`, 455 | { 456 | ... MockProps, 457 | custom_selector: '.light', 458 | custom_selector_dark: '.dark', 459 | } 460 | ) 461 | }) 462 | 463 | it('Wont create a :root {} context unless props are found', async () => { 464 | await run( 465 | `a { 466 | color: red; 467 | }`, 468 | `a { 469 | color: red; 470 | }`, 471 | { 472 | ... MockProps 473 | } 474 | ) 475 | }) 476 | 477 | it('Can jit a light and dark adaptive prop', async () => { 478 | await run( 479 | `p { 480 | color: var(--text); 481 | }`, 482 | `:root { 483 | --text: white; 484 | } 485 | p { 486 | color: var(--text); 487 | } 488 | @media (prefers-color-scheme: dark) { 489 | :root { 490 | --text: black; 491 | } 492 | }`, 493 | MockProps 494 | ) 495 | }) 496 | 497 | it('Can jit a light and dark color with a custom adaptive prop parameter', async () => { 498 | await run( 499 | `p { 500 | color: var(--text); 501 | }`, 502 | `:root { 503 | --text: white; 504 | } 505 | p { 506 | color: var(--text); 507 | } 508 | @media (prefers-color-scheme: dark) { 509 | :root { 510 | --text: black; 511 | } 512 | }`, 513 | { 514 | ...MockPropsWithCustomAdaptiveProp, 515 | adaptive_prop_selector: '-dark' 516 | } 517 | ) 518 | }) 519 | 520 | it('Supports parallel runners', async () => { 521 | const pluginInstance = plugin({ 522 | '--red': '#f00', 523 | '--pink': '#ffc0cb', 524 | }); 525 | 526 | let [resultA, resultB, resultC, resultD] = await Promise.all([ 527 | postcss([pluginInstance]).process(`a { color: var(--red); }`, { from: undefined }), 528 | postcss([pluginInstance]).process(`a { color: var(--pink); }`, { from: undefined }), 529 | postcss([pluginInstance]).process(`a { color: var(--red); }`, { from: undefined }), 530 | postcss([pluginInstance]).process(`a { color: var(--pink); }`, { from: undefined }), 531 | ]) 532 | 533 | let resultE = await postcss([pluginInstance]).process(`a { color: green; }`, { from: undefined }) 534 | 535 | expect(resultA.css).toEqual(':root { --red: #f00; }\na { color: var(--red); }') 536 | expect(resultA.warnings()).toHaveLength(0) 537 | 538 | expect(resultB.css).toEqual(':root { --pink: #ffc0cb; }\na { color: var(--pink); }') 539 | expect(resultB.warnings()).toHaveLength(0) 540 | 541 | expect(resultC.css).toEqual(':root { --red: #f00; }\na { color: var(--red); }') 542 | expect(resultC.warnings()).toHaveLength(0) 543 | 544 | expect(resultD.css).toEqual(':root { --pink: #ffc0cb; }\na { color: var(--pink); }') 545 | expect(resultD.warnings()).toHaveLength(0) 546 | 547 | expect(resultE.css).toEqual('a { color: green; }') 548 | expect(resultE.warnings()).toHaveLength(0) 549 | }) 550 | 551 | it('Supports parallel runners when reading from a file', async () => { 552 | const pluginInstance = plugin({ files: ['./props.test.css'] }); 553 | 554 | let [resultA, resultB, resultC, resultD] = await Promise.all([ 555 | postcss([pluginInstance]).process(`a { color: var(--red); }`, { from: undefined }), 556 | postcss([pluginInstance]).process(`a { color: var(--pink); }`, { from: undefined }), 557 | postcss([pluginInstance]).process(`a { color: var(--red); }`, { from: undefined }), 558 | postcss([pluginInstance]).process(`a { color: var(--pink); }`, { from: undefined }), 559 | ]) 560 | 561 | let resultE = await postcss([pluginInstance]).process(`a { color: green; }`, { from: undefined }) 562 | 563 | expect(resultA.css).toEqual(':root { --red: #f00; }\na { color: var(--red); }') 564 | expect(resultA.warnings()).toHaveLength(0) 565 | 566 | expect(resultB.css).toEqual(':root { --pink: #ffc0cb; }\na { color: var(--pink); }') 567 | expect(resultB.warnings()).toHaveLength(0) 568 | 569 | expect(resultC.css).toEqual(':root { --red: #f00; }\na { color: var(--red); }') 570 | expect(resultC.warnings()).toHaveLength(0) 571 | 572 | expect(resultD.css).toEqual(':root { --pink: #ffc0cb; }\na { color: var(--pink); }') 573 | expect(resultD.warnings()).toHaveLength(0) 574 | 575 | expect(resultE.css).toEqual('a { color: green; }') 576 | expect(resultE.warnings()).toHaveLength(0) 577 | }) 578 | 579 | // situation encountered when using postcs-jit-props for Open Props 580 | // together with having @nuxt/fonts module with no global font definition 581 | // it still creates an empty .nuxt/nuxt-fonts-global.css file 582 | // and postcs-jit-props started to fail trying to parse it 583 | // -- 584 | // fixed by adding "node.first" null check into parsing method 585 | // (lines 130 and 136 in index.js) 586 | 587 | it('Parses an empty file and rule', async () => { 588 | const pluginInstance = plugin({ files: ['./props.test.empty.css'] }); 589 | let result = await postcss([pluginInstance]).process(''); 590 | expect(result.css).toEqual(""); 591 | expect(result.warnings()).toHaveLength(0); 592 | }) 593 | -------------------------------------------------------------------------------- /package.json: -------------------------------------------------------------------------------- 1 | { 2 | "name": "postcss-jit-props", 3 | "version": "1.0.16", 4 | "description": "PostCSS plugin to insert variables from a data source based on discovered usage", 5 | "keywords": [ 6 | "postcss", 7 | "css", 8 | "postcss-plugin", 9 | "css-vars", 10 | "css-custom-properties" 11 | ], 12 | "types": "index.d.ts", 13 | "scripts": { 14 | "test": "jest --coverage && eslint .", 15 | "dev": "jest --coverage --watch", 16 | "lint": "eslint ." 17 | }, 18 | "author": "Adam Argyle ", 19 | "license": "Apache-2.0", 20 | "repository": { 21 | "type": "git", 22 | "url": "git+https://github.com/GoogleChromeLabs/postcss-jit-props.git" 23 | }, 24 | "engines": { 25 | "node": ">=10.0.0" 26 | }, 27 | "peerDependencies": { 28 | "postcss": "^8.2.8" 29 | }, 30 | "devDependencies": { 31 | "clean-publish": "^2.1.0", 32 | "eslint": "^7.21.0", 33 | "eslint-plugin-jest": "^24.2.1", 34 | "jest": "^26.6.3", 35 | "lint-staged": "^10.5.4", 36 | "postcss": "^8.2.8", 37 | "simple-git-hooks": "^2.0.2" 38 | }, 39 | "simple-git-hooks": { 40 | "pre-commit": "npx lint-staged" 41 | }, 42 | "lint-staged": { 43 | "*.js": "eslint --fix" 44 | }, 45 | "eslintConfig": { 46 | "parserOptions": { 47 | "ecmaVersion": 2020 48 | }, 49 | "env": { 50 | "node": true, 51 | "es6": true 52 | }, 53 | "extends": [ 54 | "eslint:recommended", 55 | "plugin:jest/recommended" 56 | ], 57 | "rules": { 58 | "jest/expect-expect": "off" 59 | } 60 | }, 61 | "jest": { 62 | "testEnvironment": "node", 63 | "coverageThreshold": { 64 | "global": { 65 | "statements": 90 66 | } 67 | } 68 | }, 69 | "dependencies": { 70 | "tiny-glob": "^0.2.9" 71 | } 72 | } 73 | -------------------------------------------------------------------------------- /props.test.css: -------------------------------------------------------------------------------- 1 | @custom-media --dark (prefers-color-scheme: dark); 2 | 3 | :root { 4 | --red: #f00; 5 | --pink: #ffc0cb; 6 | --h: 200; 7 | --s: 50%; 8 | --l: 50%; 9 | --size-1: 1rem; 10 | --size-2: 2rem; 11 | --fade-in: fade-in .5s ease; 12 | } 13 | 14 | @keyframes fade-in {to { opacity: 1 }} -------------------------------------------------------------------------------- /props.test.empty.css: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/GoogleChromeLabs/postcss-jit-props/4099bde8a8d77a7c66957014042d006c79fe6961/props.test.empty.css --------------------------------------------------------------------------------