We want to migrate the unit tests from tap to jest, not just because jest has almost 100x more weekly downloads than tap, but also because jest is more delightful.
Unit test for tap are saved in test/unit and use the rollup output. We will move the unit tests to the same folder as the source code they asses and make them import directly the typescript source files.
While migrating a test, keep in mind that someone has to review what you did. Make sure that your diffs will be easy to review and show up nicely in git and GitHub. In case of doubt it is better to make too many commits than too few.
Manual steps can be seen below, if you would like a script to do is automatically use the following:
node codemods.js --auto test/unit/symbol/anchor.test.js
It will create a branch, move ot it, rename file, run code change and commit with the relavant messages...
We will migrate symbol/anchor.test.js. First move, rename to typescript, and commit:
git mv test/unit/symbol/anchor.test.js src/symbol/anchor.test.ts
git commit -m "Move and rename"
Run jest-codemods:
npx jest-codemods --force src/symbol/anchor.test.ts
> Babel
> Tape
> Yes, and I'm not afraid of false positive transformations
> Yes, use the globals provided by Jest (recommended)
Run
git add src/symbol/anchor.test.ts
git commit -m "Run jest-codemods"
If there are no async tests in the file you are migrating run the custom codemods script with:
node codemods.js src/symbol/anchor.test.ts
Otherwise, if there are async tests, use:
node codemods.js --async src/symbol/anchor.test.ts
Lint and commit
npm run lint -- --fix
git add src/symbol/anchor.test.ts
git commit -m "Run custom codemods"
Fix remaining typescript errors by hand.
Run jest with:
npm run test-jest
Fix lint with:
npm run lint -- --fix
Finish:
git add src/symbol/anchor.test.ts
git commit -m "Migrate symbol/anchor.test.js"
Once we have migrated all tests to jest we should remove the helper script codemods.js and get rid of replace-in-file, jest-codemods and jscodeshift in package.json.