react-class-to-data-attr codemod

Problem

Your codebase uses certain classes for something other than styling, and you want to move them out of className and into a data-attribute to prevent mixing the two. A common use case is for having selectors used only for testing.

Solution

Run something like the following to automate moving those classes to a data-attribute. As a bonus, it removes the prefix you previously needed to differentiate it from styling classes.

jscodeshift -t react-class-to-data-attr.js <path-to-transform>

Examples

Below inputs are JSX elements within a React component, and the outputs are the result of running the script.

// input
<button className="test-add-button">Add</button>
// transformed output
<button data-test="add-button">Add</button>

// input
<button className="btn test-add-button btn-primary">Add</button>
// transformed output
<button className="btn btn-primary" data-test="add-button">Add</button>

// input
<button className={`btn btn-${theme} test-add-button`}>Add</button>
// transformed output
<button className={`btn btn-${theme}`} data-test="add-button">Add</button>

// input, where the file imports the 'classNames' library
<input className={classNames('test-name-input', {disabled: isDisabled})} />
// transformed output
<input className={classNames({disabled: isDisabled})} data-test="name-input" />

See the config options for how to handle custom classname prefixes and data-attribute names.

Setup

npm install -g jscodeshift
git clone https://github.com/ZachGawlik/react-class-to-data-attr-codemod
cd react-class-to-data-attr-codemod/src
jscodeshift -t react-class-to-data-attr.js <path>
- <path> represents the file, directory, or glob of files to transform
- use the --extensions option to transform more than just .js files, e.g. --extensions js,jsx
- if you use flowtype, you might also need to use --parser=flow;
- append -d -p to avoid writing to file and to print the transformed output

Custom Configuration Options

--class-name-prefix sets the filter for what classnames to transform. Defaults to test-

--data-key sets the name of the data-attribute for transformed classes. Defaults to test

For example,