merceyzbabel-plugin-optimize-clsx
Babel plugin to optimize the use of clsx, classnames, and all libraries with a compatible API
Install
yarn add babel-plugin-optimize-clsx --dev
or
npm install babel-plugin-optimize-clsx --save-devRequirements
| Name | Version |
|---|---|
| Babel | ^7.0.0 |
| Node | >=8 |
Examples
Object properties
clsx({
[classes.disabled]: disabled,
[classes.focusVisible]: focusVisible && !disabled,
});
// Transforms to
clsx(disabled && classes.disabled, focusVisible && !disabled && classes.focusVisible);Conditional expressions
clsx({
[classes.disabled]: disabled,
[classes.focusVisible]: focusVisible && !disabled,
});
// Transforms to
clsx(disabled ? classes.disabled : focusVisible && classes.focusVisible);Combine arguments
clsx({
[classes.focusVisible]: this.state.focusVisible,
[focusVisibleClassName]: this.state.focusVisible,
});
// Transforms to
clsx(this.state.focusVisible && [classes.focusVisible, focusVisibleClassName]);PropTypes
function foo(props) {
const { position: p } = props;
const x = clsx({
[classes.x]: p === 'top',
[classes.y]: p === 'bottom',
});
}
foo.propTypes = {
position: PropTypes.oneOf(['top', 'bottom']),
};
// Transforms to
function foo(props) {
const { position: p } = props;
const x = clsx(p === 'top' ? classes.x : classes.y);
}
foo.propTypes = {
position: PropTypes.oneOf(['top', 'bottom']),
};String literals
const x = clsx({
btn: true,
'col-md-1': true,
['btn-primary']: true,
});
// Transforms to
const x = 'btn col-md-1 btn-primary';Unnecessary function calls
const x = clsx({
btn: true,
'btn-foo': isDisabled,
'btn-bar': !isDisabled,
});
// Transforms to
const x = 'btn ' + (isDisabled ? 'btn-foo' : 'btn-bar');Benchmarks
Benchmarks can be found in the benchmark directory
Options
| Name | Type | Default value |
|---|---|---|
libraries |
string[] |
['clsx', 'classnames'] |
By default the plugin looks for import and require statements for clsx and classnames and uses that to know which function calls to optimize. If you're using another library with a compatible API you can overwrite that with this option.
{
"plugins": [
[
"babel-plugin-optimize-clsx",
{
"libraries": ["clsx", "classnames", "my-custom-library"]
}
]
]
}| Name | Type | Default value |
|---|---|---|
functionNames |
string[] |
[] |
If you want the plugin to match on all functions with a specific name, no matter where it comes from you can specify them using this option. An example for this is if you have clsx as a global function and thus don't import it.
{
"plugins": [
[
"babel-plugin-optimize-clsx",
{
"functionNames": ["myClsxImplementation"]
}
]
]
}| Name | Type | Default value |
|---|---|---|
removeUnnecessaryCalls |
boolean |
true |
By default the plugin will remove unnecessary function calls and if all calls are removed, imports. If you need to keep them, you can set this option to false.
Example of some unnecessary calls
import clsx from 'clsx';
const x = clsx('foo', 'bar');
const y = clsx({ classA: foo === 'a', classB: foo !== 'a' });
const z = clsx({
classA: foo === 'a',
classB: foo !== 'a',
classC: bar === 'c',
classD: bar !== 'c',
});
// Transforms to
const x = 'foo bar';
const y = foo === 'a' ? 'classA' : 'classB';
const z = (foo === 'a' ? 'classA ' : 'classB ') + (bar === 'c' ? 'classC' : 'classD');| Name | Type | Default value |
|---|---|---|
collectCalls |
boolean |
false |
Writes all function calls, before they are optimized, to a file. Used to help test the plugin on repositories.