Tool for transforming CSS into JS
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- Converts CSS to JS
- Supports multiple input and output formats (inline code, files, directories)
- Generates style objects as e6 exports with options to split into separate files
- Reverse media query distribution
Install:
npm install @americanexpress/css-to-js --save-dev CLI:
css-to-js <inputPath> <outputPath> (--mediaReverse) (--splitFile | --shakeFile)
Arguments:
inputPath input path to css file or dir of css files outputPath output path to js file or dir Options:
--help --version --mediaReverse reverse mediaQuery style properties --splitFile generate multiple files with exports for each selector in css file
--shakeFile generate single file with exports for each selector in css file
If shakeFile or splitFile is not specified, generate single file with single exported object with selectors in css file as keys
See API for more details.Node:
import { convert } from 'css-to-js';
//Input CSS string, Outputs JS Object
convert(`.myClass { color: 'red' }`);
//Input CSS string, Output file exporting JS Object
convert(`.myClass { color: 'red' }`, { outputType: 'file', outputPath: 'outPath' });
//Input CSS file path, Output file exporting JS Object
convert('absolute-path-to-css-file', { outputType: 'file', outputPath: 'outPath' });
//Input CSS file path, Output file exporting multiple JS Objects
convert('absolute-path-to-css-file', { outputType: 'shakeFile', outputPath: 'outPath' });
//Input CSS file path, Outputs dir of files exporting single JS Objects (If treeshaking not supported)
convert('absolute-path-to-css-file', { outputType: 'splitFile', outputPath: 'outPath' });
//Input Dir path of CSS files, Output array of JS Objects
convert('absolute-path-to-dir');
//Input Dir path of CSS files, Output dir of converted files exporting JS Object
convert('absolute-path-to-dir'', { outputType: 'file', outputPath: 'outPath' });
| Convert Function | Input Type | Output Type(s) |
|---|---|---|
| convert(css); | Path to single CSS file or string of CSS code | JS style object |
| convert(css, { outputType: 'file', outputPath: 'example.js' }); | Path to single CSS file or string of CSS code | Generated JS file 'example.js' with a default export of a JS style object |
| convert(css, { outputType: 'shakeFile', outputPath: 'shakeExample.js' }); | Path to single CSS file or string of CSS code | Generated JS file 'shakeExample.js' with multiple named exports of JS style objects |
| convert(css, { outputType: 'splitFile', outputPath: 'splitExample' }); | Path to single CSS file or string of CSS code | Generated directory 'splitExample' with multiple files each with a default export of a JS style object |
| convert(dirPath); | Path to directory of CSS files | Array of JS style objects |
| convert(dirPath, { outputType: 'file', outputPath: 'exampleDir' }); | Path to directory of CSS files | Generated directory of JS files; Each file has a default export of a JS style object and is named after the corresponding css file |
| convert(dirPath, { outputType: 'shakeFile', outputPath: 'shakeExample.js' }); | Path to directory of CSS files | Generated directory of JS files; Each file has multiple named exports of JS style objects and is named after the corresponding css file |
| convert(dirPath, { outputType: 'splitFile', outputPath: 'splitExample' }); | Path to directory of CSS files | Generated directory of directories; Each file has a default export of a JS style object and is named after the corresponding css file |
Sample Input: nav.css
.class1 {
color: 'red';
}
.class2 {
color: 'blue';
}Example 1: File - Creates a file with a single object export representing tree of full converted css
convert(
path.resolve(__dirname, './nav.css'),
{
outputType: 'file',
outputPath: path.resolve(__dirname, '../example1.js')
}
);
Output: Example1.js
export default {
class1: { color: 'red' },
class2: { color: 'blue' },
};Example 2: ShakeFile - Create file with multiple exports representing each selector of converted css
(Useful for tree-shaking style objects that do not get used)
convert(
path.resolve(__dirname, './nav.css'),
{
outputType: 'shakeFile',
outputPath: path.resolve(__dirname, '../example2.js')
}
);
Output: Example2.js
export const class1 = { color: 'red' };
export const class2 = { color: 'blue' };Example 3: SplitFile - Create multiple files with exports representing each selector of converted css
(Useful for excluding style objects that do not get used if tree-shaking is not implemented)
convert(
path.resolve(__dirname, './nav.css'),
{
outputType: 'splitFile',
outputPath: path.resolve(__dirname, '../example3')
}
);
Output: Example3/
class1.js
export default { color: 'red' };class2.js
export default { color: 'blue' };Note: mediaReverse is always true if output type is shakeFile or splitFile
Sometimes it's useful to have the styles located in media queries distributed into the selector properties rather than be their own property.
If the mediaReverse flag is set to true, reverse the positioning of media queries to be inside the property.
nav.css
.class1 { color: 'red'; }
@media (min-width:500px) {
.class1 { color: 'blue'; }
}
@media (min-width:1000px) {
.class1 { color: 'green'; }
} If mediaReverse is not set:
convert(
path.resolve(__dirname, './nav.css'),
{
outputType: 'file',
outputPath: path.resolve(__dirname, '../example4.js')
}
);
Example4.js
export default {
class1: { color: 'red' },
'@media (min-width:500px)': {
class2: { color: 'blue' },
},
'@media (min-width:1000px)': {
class2: { color: 'green' },
},
};If mediaReverse is set to true:
convert(
path.resolve(__dirname, './nav.css'),
{
outputType: 'file',
outputPath: path.resolve(__dirname, '../example4.js'),
mediaReverse: true
}
);
Example4.js
export default {
class1: { color: 'red' },
class2: {
'@media (min-width:500px)': {
color: 'blue',
},
'@media (min-width:1000px)': {
color: 'green',
},
},
};These commands will be automatically run during normal git operations like committing code.
pre-commit
This hook runs npm test before allowing a commit to be checked in.
commit-msg
This hook verifies that your commit message matches the One Amex conventions. See the commit
message section in the CONTRIBUTING.md.
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Please feel free to open pull requests and see CONTRIBUTING.md for commit formatting details.
Any contributions made under this project will be governed by the Apache License 2.0.
This project adheres to the American Express Community Guidelines.
By participating, you are expected to honor these guidelines.