ci: add script to generate global changelog (#1256)

package.json

@@ -19,7 +19,7 @@
     "prettier:check": "prettier --check '**/*.{ts,tsx,css,md,mdx,sol}'",
     "release:check": "changeset status --verbose --since=origin/main",
     "release:publish": "pnpm install && pnpm build && changeset publish",
-    "release:version": "changeset version && pnpm install --lockfile-only",
+    "release:version": "changeset version && pnpm install --lockfile-only && pnpx bun scripts/changelog.ts",
     "sort-package-json": "npx sort-package-json package.json 'packages/*/package.json' 'templates/*/package.json' 'templates/*/packages/*/package.json' 'examples/*/package.json' 'examples/*/packages/*/package.json' 'integration/*/package.json' 'integration/*/packages/*/package.json' 'docs/package.json'",
     "test": "pnpm recursive run test"
   },
@@ -31,10 +31,12 @@
   "devDependencies": {
     "@changesets/changelog-github": "^0.4.8",
     "@changesets/cli": "^2.26.1",
+    "@types/node": "^18.15.11",
     "@typescript-eslint/eslint-plugin": "5.46.1",
     "@typescript-eslint/parser": "5.46.1",
     "chalk": "^5.2.0",
     "eslint": "8.29.0",
+    "execa": "^7.0.0",
     "husky": ">=6",
     "lint-staged": ">=10",
     "prettier": "^2.8.4",

scripts/changelog.ts

@@ -0,0 +1,159 @@
+/**
+ * This is a workaround until changesets natively supports publishing a
+ * central changelog (https://github.com/changesets/changesets/issues/1059).
+ */
+
+import { execa } from "execa";
+import { readFileSync, writeFileSync } from "node:fs";
+
+//--------- CONSTANTS
+
+const REPO_URL = process.env.REPO_URL ?? "https://github.com/latticexyz/mud";
+const CHANGELOG_PATH = process.env.CHANGELOG_PATH ?? "CHANGELOG.md";
+
+enum ChangeType {
+  PATCH,
+  MINOR,
+  MAJOR,
+}
+
+const changeTypes = {
+  patch: ChangeType.PATCH,
+  minor: ChangeType.MINOR,
+  major: ChangeType.MAJOR,
+} as const;
+
+type ChangelogItem = {
+  packages: {
+    package: string;
+    type: string;
+  }[];
+  type: ChangeType;
+  description: string;
+};
+
+type GitMetadata = {
+  commitHash: string;
+  authorName: string;
+  authorEmail: string;
+  title: string;
+};
+
+await appendChangelog();
+
+//----------- UTILS
+
+async function appendChangelog() {
+  // Reset current changelog to version on main
+  await execa("git", ["checkout", "main", "--", CHANGELOG_PATH]);
+
+  // Load the current changelog
+  const currentChangelog = readFileSync(CHANGELOG_PATH).toString();
+
+  // Append the new changelog at the up
+  const newChangelog = await renderChangelog();
+  writeFileSync(CHANGELOG_PATH, `${newChangelog}\n${currentChangelog}`);
+}
+
+async function renderChangelog() {
+  const changes = await getChanges();
+  const version = await getVersion();
+
+  return `
+# Version ${version}
+
+## Major changes
+
+${await renderChangelogItems(changes.major)}
+## Minor changes
+
+${await renderChangelogItems(changes.minor)}
+## Patch changes
+
+${await renderChangelogItems(changes.patch)}
+`;
+}
+
+async function renderChangelogItems(changelogItems: (ChangelogItem & GitMetadata)[]) {
+  let output = "";
+
+  for (const changelogItem of changelogItems) {
+    output += `1. **[${changelogItem.title}](${REPO_URL}/commit/${changelogItem.commitHash})** (${changelogItem.packages
+      .map((e) => e.package)
+      .join(", ")})
+
+${changelogItem.description}
+`;
+  }
+
+  return output;
+}
+
+async function getVersion() {
+  return "2.0.0-next.1";
+}
+
+async function getChanges() {
+  // Get the diff of the current branch to main
+  const changesetDiff = (await execa("git", ["diff", "main", ".changeset/pre.json"])).stdout;
+
+  // Get the list of changesets
+  const addedLinesRegex = /\+\s+"([^"]+)"/g;
+  const addedChangesets = [...changesetDiff.matchAll(addedLinesRegex)].map((match) => match[1]);
+
+  // Load the contents of each changeset and metadata from git
+  const changesets = await Promise.all(
+    addedChangesets.map(async (addedChangeset) => {
+      const changesetPath = `.changeset/${addedChangeset}.md`;
+      const changeset = readFileSync(changesetPath).toString();
+      const gitLog = (await execa("git", ["log", changesetPath])).stdout;
+      return { ...parseChangeset(changeset), ...parseGitLog(gitLog) };
+    })
+  );
+
+  // Sort the changesets into patch, minor and major updates
+  const patch = changesets.filter((change) => change.type === ChangeType.PATCH);
+  const minor = changesets.filter((change) => change.type === ChangeType.MINOR);
+  const major = changesets.filter((change) => change.type === ChangeType.MAJOR);
+
+  return { patch, minor, major };
+}
+
+function notNull<T>(element: T | undefined | null | ""): element is T {
+  return Boolean(element);
+}
+
+/**
+ * Parse a changeset string into a more usable format (list of updated packages, change type, description)
+ */
+function parseChangeset(changeset: string): ChangelogItem {
+  // Remove first separator
+  const separatorString = "---\n";
+  let separatorIndex = changeset.indexOf(separatorString);
+  changeset = changeset.substring(separatorIndex + separatorString.length);
+
+  // Parse list of changed packages and description
+  separatorIndex = changeset.indexOf(separatorString);
+  const packages = changeset
+    .substring(0, separatorIndex)
+    .split("\n")
+    .map((line) => {
+      const match = line.match(/"([^"]+)":\s*(\w+)/);
+      if (match) return { package: match[1], type: match[2] as "patch" | "minor" | "major" };
+    })
+    .filter(notNull);
+  const description = changeset.substring(separatorIndex + separatorString.length);
+
+  // Find the strongest update type
+  const type = Math.max(...packages.map((change) => changeTypes[change.type]));
+
+  return { packages, description, type };
+}
+
+function parseGitLog(log: string): GitMetadata {
+  // Thanks ChatGPT
+  const [, commitHash, authorName, authorEmail, title] =
+    log.match(/commit (\w+)[\s\S]*?Author: ([^<]+) <([^>]+)>[\s\S]*?\n\n\s{4}([^\n]+)/) ?? [];
+
+  return { commitHash, authorName, authorEmail, title };
+}