ce-codemods

Codemods to convert from custom-elements v0 to v1

Installation

npm install

Prerequisites

Install jscodeshift to run the codemod scripts:

npm install -g jscodeshift

Usage

To run a single transform

jscodeshift -t ./src/[transform-name]/index.js path/to/files

To run all the transforms

jscodeshift -t ./src/index.js path/to/files

Writing your own codemod

When working a new transform, it's suggested to use ASTExplorer which offers the best development experience. Configure to use jscodeshift as the transform.

Once you are happy with the result, you can transfer it over to this repo and follow the folder structure described below.

Using the test framework

This repo comes with a testing setup to help with testing multiple scenarios using fixtures and Jest's snapshot testing.

Each transform should be placed in its own folder under ./src and needs to have the following folder structure:

 #transform directory
./src/transform-name
| #the jscodeshift transform
| index.js
| #Jest's default test directory
| __tests__
  | #the test entry
  | transform-name-test.js
  | #directory to place fixtures
  | __fixtures__
    | # fixture files are passed to your transform during testing
    | # each one should cover one scenario
    | scenario-one.fixture.js
    | other-scenario.fixture.js

In the test entry, use ./util/defineSnapshotTests to run the fixture tests

const defineSnapshotTests = require('../../../util/defineSnapshotTests');

describe('transform-name', function() {
  //run fixture tests
  defineSnapshotTests(__dirname);
  //other tests
  describe('other tests', function () {})
});

Each fixture file will be run against your transform twice in

To run the tests, simply run npm run test or jest

Read Jest's documentation on snapshots