Migrate to Changesets (#63)

It's looking like our config will require numerous breaking changes to
get to ESLint v8 compatibility (#62). If we stuck with semantic-release
we'd either need to get creative with branching, have one mega PR or
release a bunch of intermediary major versions that add little value.

Instead, switch to Changesets. This is used in a number of our OSS repos
and makes it easier to bundle multiple changes into a release. We
support previewing the release notes with and without a `GITHUB_TOKEN`
via `yarn version`.

.changeset/README.md

@@ -0,0 +1,8 @@
+# Changesets
+
+Hello and welcome! This folder has been automatically generated by `@changesets/cli`, a build tool that works
+with multi-package repos, or single-package repos to help you version and publish your code. You can
+find the full documentation for it [in our repository](https://github.com/changesets/changesets)
+
+We have a quick list of common questions to get you started engaging with this project in
+[our documentation](https://github.com/changesets/changesets/blob/main/docs/common-questions.md)

.changeset/changelog.js

@@ -0,0 +1,162 @@
+const {
+  getInfo,
+  getInfoFromPullRequest,
+} = require('@changesets/get-github-info');
+
+/**
+ * Adapted from `@changesets/cli`.
+ *
+ * {@link https://github.com/atlassian/changesets/blob/%40changesets/cli%402.17.0/packages/cli/src/changelog/index.ts}
+ *
+ * @type import('@changesets/types').ChangelogFunctions
+ */
+const defaultChangelogFunctions = {
+  getDependencyReleaseLine: async (changesets, dependenciesUpdated) => {
+    if (dependenciesUpdated.length === 0) return '';
+
+    const changesetLinks = changesets.map(
+      (changeset) => `- Updated dependencies [${changeset.commit}]`,
+    );
+
+    const updatedDependenciesList = dependenciesUpdated.map(
+      (dependency) => `  - ${dependency.name}@${dependency.newVersion}`,
+    );
+
+    return [...changesetLinks, ...updatedDependenciesList].join('\n');
+  },
+  getReleaseLine: async (changeset) => {
+    const [firstLine, ...futureLines] = changeset.summary
+      .split('\n')
+      .map((l) => l.trimRight());
+
+    const suffix = changeset.commit;
+
+    return `\n\n- ${firstLine}${suffix ? ` (${suffix})` : ''}\n${futureLines
+      .map((l) => `  ${l}`)
+      .join('\n')}`;
+  },
+};
+
+/**
+ * Adapted from `@changesets/changelog-github`.
+ *
+ * {@link https://github.com/atlassian/changesets/blob/%40changesets/changelog-github%400.4.1/packages/changelog-github/src/index.ts}
+ *
+ * @type import('@changesets/types').ChangelogFunctions
+ */
+const gitHubChangelogFunctions = {
+  getDependencyReleaseLine: async (
+    changesets,
+    dependenciesUpdated,
+    options,
+  ) => {
+    if (!options.repo) {
+      throw new Error(
+        'Please provide a repo to this changelog generator like this:\n"changelog": ["./changelog.js", { "repo": "org/repo" }]',
+      );
+    }
+    if (dependenciesUpdated.length === 0) return '';
+
+    const changesetLink = `- Updated dependencies [${(
+      await Promise.all(
+        changesets.map(async (cs) => {
+          if (cs.commit) {
+            let { links } = await getInfo({
+              repo: options.repo,
+              commit: cs.commit,
+            });
+            return links.commit;
+          }
+        }),
+      )
+    )
+      .filter((_) => _)
+      .join(', ')}]:`;
+
+    const updatedDependenciesList = dependenciesUpdated.map(
+      (dependency) => `  - ${dependency.name}@${dependency.newVersion}`,
+    );
+
+    return [changesetLink, ...updatedDependenciesList].join('\n');
+  },
+  getReleaseLine: async (changeset, _type, options) => {
+    if (!options || !options.repo) {
+      throw new Error(
+        'Please provide a repo to this changelog generator like this:\n"changelog": ["./changelog.js", { "repo": "org/repo" }]',
+      );
+    }
+
+    /** @type number | undefined */
+    let prFromSummary;
+    /** @type string | undefined */
+    let commitFromSummary;
+
+    const replacedChangelog = changeset.summary
+      .replace(/^\s*(?:pr|pull|pull\s+request):\s*#?(\d+)/im, (_, pr) => {
+        let num = Number(pr);
+        if (!isNaN(num)) prFromSummary = num;
+        return '';
+      })
+      .replace(/^\s*commit:\s*([^\s]+)/im, (_, commit) => {
+        commitFromSummary = commit;
+        return '';
+      })
+      .replace(/^\s*(?:author|user):\s*@?([^\s]+)/gim, (_, user) => {
+        usersFromSummary.push(user);
+        return '';
+      })
+      .trim();
+
+    const [firstLine, ...futureLines] = replacedChangelog
+      .split('\n')
+      .map((l) => l.trimRight());
+
+    const links = await (async () => {
+      if (prFromSummary !== undefined) {
+        let { links } = await getInfoFromPullRequest({
+          repo: options.repo,
+          pull: prFromSummary,
+        });
+        if (commitFromSummary) {
+          links = {
+            ...links,
+            commit: `[\`${commitFromSummary}\`](https://github.com/${options.repo}/commit/${commitFromSummary})`,
+          };
+        }
+        return links;
+      }
+      const commitToFetchFrom = commitFromSummary || changeset.commit;
+      if (commitToFetchFrom) {
+        let { links } = await getInfo({
+          repo: options.repo,
+          commit: commitToFetchFrom,
+        });
+        return links;
+      }
+      return {
+        commit: null,
+        pull: null,
+        user: null,
+      };
+    })();
+
+    const suffix = links.pull ?? links.commit;
+
+    return [
+      `\n- ${firstLine}${suffix ? ` (${suffix})` : ''}`,
+      ...futureLines.map((l) => `  ${l}`),
+    ].join('\n');
+  },
+};
+
+if (process.env.GITHUB_TOKEN) {
+  module.exports = gitHubChangelogFunctions;
+} else {
+  console.warn(
+    `Defaulting to Git-based versioning.
+Enable GitHub-based versioning by setting the GITHUB_TOKEN environment variable.
+This requires a GitHub personal access token with the \`public_repo\` scope: https://github.com/settings/tokens/new`,
+  );
+
+  module.exports = defaultChangelogFunctions;
+}

.changeset/config.json

@@ -0,0 +1,10 @@
+{
+  "$schema": "https://unpkg.com/@changesets/config@1.6.1/schema.json",
+  "changelog": ["./changelog.js", { "repo": "seek-oss/eslint-config-seek" }],
+  "commit": false,
+  "linked": [],
+  "access": "public",
+  "baseBranch": "master",
+  "updateInternalDependencies": "patch",
+  "ignore": []
+}

.github/workflows/test-and-release.yml → .github/workflows/release.yml

@@ -1,34 +1,34 @@
-name: Test & Release
+name: Release
 
 on:
-  - pull_request
-  - push
+  push:
+    branches:
+      - beta
+      - master
 
 jobs:
-  test-and-release:
-    name: Test & Release
+  release:
+    name: Release
     runs-on: ubuntu-latest
     env:
       CI: true
     steps:
       - name: Check out repo
         uses: actions/checkout@main
-        with:
-          lfs: true
 
-      - name: Set up Node.js 14.x
+      - name: Set up Node.js 16.x
         uses: actions/setup-node@main
         with:
-          node-version: 14.x
+          node-version: 16.x
 
       - name: Install dependencies
         run: yarn --immutable
 
-      - name: Test
-        run: yarn test
-
       - name: Release
-        run: yarn release
+        uses: changesets/action@master
+        with:
+          publish: yarn release
+          version: yarn version
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           NPM_TOKEN: ${{ secrets.SEEK_OSS_CI_NPM_TOKEN }}

.github/workflows/test.yml

@@ -0,0 +1,26 @@
+name: Test
+
+on:
+  - pull_request
+  - push
+
+jobs:
+  test:
+    name: Test
+    runs-on: ubuntu-latest
+    env:
+      CI: true
+    steps:
+      - name: Check out repo
+        uses: actions/checkout@main
+
+      - name: Set up Node.js 16.x
+        uses: actions/setup-node@main
+        with:
+          node-version: 16.x
+
+      - name: Install dependencies
+        run: yarn --immutable
+
+      - name: Test
+        run: yarn test

package.json

@@ -1,26 +1,21 @@
 {
   "name": "eslint-config-seek",
-  "version": "0.0.0-development",
+  "version": "7.0.9",
   "description": "ESLint configuration used by SEEK",
   "main": ".eslintrc.js",
   "repository": {
     "type": "git",
     "url": "https://github.com/seek-oss/eslint-config-seek.git"
   },
-  "author": "Seek",
+  "author": "SEEK",
   "license": "MIT",
   "bugs": {
     "url": "https://github.com/seek-oss/eslint-config-seek/issues"
   },
   "scripts": {
+    "release": "changeset release",
     "test": "eslint .",
-    "commit": "git-cz",
-    "release": "semantic-release"
-  },
-  "husky": {
-    "hooks": {
-      "commit-msg": "commitlint --edit --extends seek"
-    }
+    "version": "changeset version && prettier --write ."
   },
   "homepage": "https://github.com/seek-oss/eslint-config-seek#readme",
   "dependencies": {
@@ -39,25 +34,14 @@
     "find-root": "^1.1.0"
   },
   "devDependencies": {
-    "@commitlint/cli": "^8.2.0",
-    "commitizen": "^4.0.3",
-    "commitlint-config-seek": "^1.0.0",
-    "cz-conventional-changelog": "^3.0.2",
+    "@changesets/cli": "2.17.0",
+    "@changesets/get-github-info": "0.5.0",
     "eslint": "^7.14.0",
-    "husky": "^3.1.0",
-    "semantic-release": "^15.13.31",
+    "prettier": "2.4.1",
     "typescript": "^4.1.2"
   },
-  "release": {
-    "success": false
-  },
   "peerDependencies": {
     "eslint": ">=6",
     "typescript": ">=3.3"
-  },
-  "config": {
-    "commitizen": {
-      "path": "./node_modules/cz-conventional-changelog"
-    }
   }
 }