chore(ci): create custom CHANGELOG generator

.changeset/config.json

@@ -4,7 +4,7 @@
   "baseBranch": "master",
   "bumpVersionsWithWorkspaceProtocolOnly": true,
   "changelog": [
-    "@changesets/changelog-github",
+    "./endo-changelog-generator.js",
     {
       "repo": "endojs/endo"
     }

.changeset/endo-changelog-generator.js

@@ -0,0 +1,173 @@
+// @ts-check
+
+/**
+ * This is a custom `CHANGELOG.md` generator for Endo.
+ *
+ * It mimics the behavior of `conventional-changelog-conventionalcommits` and is
+ * based on `@changesets/changelog-github`. It differs from the latter in two
+ * ways:
+ *
+ * - The version header is a link to a "diff" of the changes between the
+ *   previous and current version
+ * - The version header contains a date in the format `YYYY-MM-DD`
+ *
+ * _Note_: This generator does **not** run when the "Version Packages" PR is
+ * merged; as such, the date shown may not be the date of the release itself.
+ *
+ * @see {@link https://github.com/changesets/changesets/tree/main/packages/changelog-github}
+ * @see {@link https://github.com/conventional-changelog/conventional-changelog/tree/master/packages/conventional-changelog-conventionalcommits}
+ * @module
+ */
+
+import { getInfo, getInfoFromPullRequest } from '@changesets/get-github-info';
+
+/**
+ * @import {ChangelogFunctions, NewChangesetWithCommit} from "@changesets/types"
+ */
+
+/**
+ * Fetches the links to the commit, pull request, and user from the GitHub API.
+ *
+ * @param {string} githubServerUrl The URL of the GitHub server.
+ * @param {string} repo The repository name.
+ * @param {number|undefined} prFromSummary The pull request number from the summary.
+ * @param {string|undefined} commitFromSummary The commit hash from the summary.
+ * @param {NewChangesetWithCommit} changeset The changeset object.
+ * @returns {Promise<{commit: string|null, pull: string|null, user: string|null}>} An object containing the links to the commit, pull request, and user.
+ */
+const getLinks = async (
+  githubServerUrl,
+  repo,
+  prFromSummary,
+  commitFromSummary,
+  changeset,
+) => {
+  if (prFromSummary !== undefined) {
+    let { links } = await getInfoFromPullRequest({
+      repo,
+      pull: prFromSummary,
+    });
+    if (commitFromSummary) {
+      const shortCommitId = commitFromSummary.slice(0, 7);
+      links = {
+        ...links,
+        commit: `[\`${shortCommitId}\`](${githubServerUrl}/${repo}/commit/${commitFromSummary})`,
+      };
+    }
+    return links;
+  }
+  const commitToFetchFrom = commitFromSummary || changeset.commit;
+  if (commitToFetchFrom) {
+    let { links } = await getInfo({
+      repo,
+      commit: commitToFetchFrom,
+    });
+    return links;
+  }
+  return {
+    commit: null,
+    pull: null,
+    user: null,
+  };
+};
+
+/** @type {ChangelogFunctions} */
+export default {
+  getDependencyReleaseLine: async (
+    changesets,
+    dependenciesUpdated,
+    options,
+  ) => {
+    if (!options?.repo) {
+      throw new Error(
+        'Please provide a repo to this changelog generator like this:\n"changelog": ["@changesets/changelog-github", { "repo": "org/repo" }]',
+      );
+    }
+    if (dependenciesUpdated.length === 0) return '';
+
+    const commits = await Promise.all(
+      changesets.map(async ({ commit }) => {
+        if (commit) {
+          let { links } = await getInfo({
+            repo: options.repo,
+            commit,
+          });
+          return links.commit;
+        }
+      }),
+    );
+
+    const changesetLink = `- Updated dependencies [${commits
+      .filter(value => !!value)
+      .join(', ')}]:`;
+
+    const updatedDepenenciesList = dependenciesUpdated.map(
+      dependency => `  - ${dependency.name}@${dependency.newVersion}`,
+    );
+
+    return [changesetLink, ...updatedDepenenciesList].join('\n');
+  },
+  getReleaseLine: async (changeset, _type, options) => {
+    if (!options?.repo) {
+      throw new Error(
+        'Please provide a repo to this changelog generator like this:\n"changelog": ["@changesets/changelog-github", { "repo": "org/repo" }]',
+      );
+    }
+
+    const githubServerUrl =
+      process.env.GITHUB_SERVER_URL || 'https://github.com';
+    /** @type {number | undefined} */
+    let prFromSummary;
+    /** @type {string | undefined} */
+    let commitFromSummary;
+    /** @type {string[]} */
+    let usersFromSummary = [];
+
+    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.trimEnd());
+
+    const links = await getLinks(
+      githubServerUrl,
+      options.repo,
+      prFromSummary,
+      commitFromSummary,
+      changeset,
+    );
+
+    const users = usersFromSummary.length
+      ? usersFromSummary
+          .map(
+            userFromSummary =>
+              `[@${userFromSummary}](${githubServerUrl}/${userFromSummary})`,
+          )
+          .join(', ')
+      : links.user;
+
+    const prefix = [
+      links.pull === null ? '' : ` ${links.pull}`,
+      links.commit === null ? '' : ` ${links.commit}`,
+      users === null ? '' : ` Thanks ${users}!`,
+    ].join('');
+
+    return `\n\n-${prefix ? `${prefix} -` : ''} ${firstLine}\n${futureLines
+      .map(l => `  ${l}`)
+      .join('\n')}`;
+  },
+};