Merge f21a17d into 226d028

.github/workflows/ci.yml

@@ -28,12 +28,12 @@ jobs:
           cache: 'yarn'
       - run: yarn install --frozen-lockfile
       - run: yarn build:ci
-  build-packages:
+  validate-packages:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2.3.4
       - uses: guardian/actions-setup-node@v2.4.1
         with:
           cache: 'yarn'
       - run: yarn install --frozen-lockfile
-      - run: yarn build:all
+      - run: yarn package-validation:validate

docs/08-contributing.md

@@ -64,4 +64,4 @@ $ yarn storybook
 ### Raising a pull request
 
 -   Don’t bump the package version as part of a pull request. Maintainers will take care of this as part of the release process.
--   Test that your component can be used in a real project (e.g. [dotcom-rendering](https://github.com/guardian/dotcom-rendering) or the specially-designed [source-shakedown](https://github.com/guardian/source-shakedown)). Use [`yarn link`](https://yarnpkg.com/en/docs/cli/link) to avoid having to perform a real publish, and [`yarn pack`](https://yarnpkg.com/en/docs/cli/pack) to see exactly which files would be published.
+-   Test that your component can be used in a real project (e.g. [dotcom-rendering](https://github.com/guardian/dotcom-rendering)). Use [`yarn link`](https://yarnpkg.com/en/docs/cli/link) to avoid having to perform a real publish, and [`yarn pack`](https://yarnpkg.com/en/docs/cli/pack) to see exactly which files would be published.

jest.config.js

@@ -2,5 +2,9 @@
 module.exports = {
 	preset: 'ts-jest',
 	testEnvironment: 'node',
-	testPathIgnorePatterns: ['/node_modules', '/dist'],
+	testPathIgnorePatterns: [
+		'/node_modules',
+		'/dist',
+		'packages/@guardian/source-package-validation',
+	],
 };

package.json

@@ -22,6 +22,8 @@
     "lint": "yarn lint:js && yarn lint:styles",
     "lint:js": "eslint . --ext .ts,.tsx,.js",
     "lint:styles": "stylelint src/core/**/styles.ts",
+    "package-validation": "yarn workspace @guardian/source-package-validation",
+    "package-validation:validate": "yarn build:all && yarn package-validation validate",
     "prepare": "husky install",
     "publish:release": "ts-node ./scripts/publish-release",
     "publish:release:kitchen": "ts-node ./scripts/publish-release-kitchen",

packages/@guardian/source-package-validation/README.md

@@ -0,0 +1,23 @@
+# Source Package Validation
+
+This project is used to verify the output of the Source packages.
+
+## How?
+
+It runs two checks:
+
+1. Verify that no exports have changed in the published packages
+
+    This works similar to a snapshot test in that, if anything does change, the test must be updated. This ensures that subsequent releases haven't broken the package structure or unexpectedly removed exports from the public API. It uses jest to run the test.
+
+2. Verify that no types have been removed
+
+    This test works by importing all of the types from all packages into a file and then running `tsc`. It will capture types that have been removed but not fail when new types are added so, for now, the onus is on contributors and reviewers to **remember to add new types to this file**.
+
+## Running locally
+
+Validation requires all packages to be built before running.
+
+You can run the tests including the build step by running (from the root directory): `yarn package-validation:validate`
+
+If you are running locally and want to avoid rebuilding all packages each time then you can just rebuild the package(s) that have changed an then run: `yarn package-validation validate`

packages/@guardian/source-package-validation/jest.config.js

@@ -0,0 +1,5 @@
+/** @type {import('ts-jest/dist/types').InitialOptionsTsJest} */
+module.exports = {
+	preset: 'ts-jest',
+	testEnvironment: 'node',
+};