Enhance GitHub changelog formatter with PR/commit links and contributor thanks

- Add commit hash links alongside PR links in changelog entries
- Add "Thanks @username!" attribution (matching @changesets/changelog-github format)
- Add `internalAuthors` option to suppress thanks for team members
- Support metadata overrides in changeset summaries (pr, commit, author lines)
- Linkify bare #123 issue references in summary text
- Auto-detect repo from gh CLI when not configured
- Export GithubChangelogOptions type for custom formatter use

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: theoephraim

.bumpy/github-changelog-enhancements.md

@@ -0,0 +1,12 @@
+---
+'@varlock/bumpy': patch
+---
+
+Enhance GitHub changelog formatter with PR/commit links and contributor attribution.
+
+- Add commit hash links alongside PR links in changelog entries
+- Add "Thanks @username!" attribution (matching `@changesets/changelog-github` format)
+- Add `internalAuthors` option to suppress thanks for team members
+- Support metadata overrides in changeset summaries (`pr:`, `commit:`, `author:` lines)
+- Linkify bare `#123` issue references in summary text
+- Auto-detect repo slug from `gh` CLI when not configured

packages/bumpy/src/core/changelog-github.ts

@@ -1,21 +1,30 @@
 import { tryRunArgs } from '../utils/shell.ts';
 import type { ChangelogContext, ChangelogFormatter } from './changelog.ts';
 
-interface GithubOptions {
-  repo?: string; // "owner/repo" — auto-detected if not provided
+export interface GithubChangelogOptions {
+  /** "owner/repo" — auto-detected from gh CLI if not provided */
+  repo?: string;
+  /** GitHub usernames (without @) to skip "Thanks" messages for (e.g. internal team members) */
+  internalAuthors?: string[];
 }
 
 /**
  * GitHub-enhanced changelog formatter.
- * Adds PR links and author attribution when git/gh info is available.
+ * Adds PR links, commit links, and contributor attribution when git/gh info is available.
  *
  * Usage in config:
  *   "changelog": "github"
  *   "changelog": ["github", { "repo": "dmno-dev/bumpy" }]
+ *   "changelog": ["github", { "repo": "dmno-dev/bumpy", "internalAuthors": ["theoephraim"] }]
  */
-export function createGithubFormatter(options: GithubOptions = {}): ChangelogFormatter {
+export function createGithubFormatter(options: GithubChangelogOptions = {}): ChangelogFormatter {
+  const internalAuthorsSet = new Set((options.internalAuthors ?? []).map((a) => a.toLowerCase()));
+
   return async (ctx: ChangelogContext) => {
     const { release, changesets, date } = ctx;
+    const repoSlug = options.repo ?? detectRepo();
+    const serverUrl = process.env.GITHUB_SERVER_URL || 'https://github.com';
+
     const lines: string[] = [];
     lines.push(`## ${release.newVersion}`);
     lines.push('');
@@ -27,21 +36,25 @@ export function createGithubFormatter(options: GithubOptions = {}): ChangelogFor
     if (relevantChangesets.length > 0) {
       for (const cs of relevantChangesets) {
         if (!cs.summary) continue;
-        const firstLine = cs.summary.split('\n')[0]!;
-
-        // Try to find a PR associated with this changeset
-        const prInfo = await findPrForChangeset(cs.id, options.repo);
-        if (prInfo) {
-          lines.push(`- ${firstLine} ([#${prInfo.number}](${prInfo.url})) by @${prInfo.author}`);
-        } else {
-          lines.push(`- ${firstLine}`);
-        }
+
+        // Extract metadata overrides from summary (pr, commit, author lines)
+        const { cleanSummary, overrides } = extractSummaryMeta(cs.summary);
+
+        // Look up git/PR info, with overrides taking precedence
+        const gitInfo = resolveChangesetInfo(cs.id, repoSlug, serverUrl, overrides);
+
+        const summaryLines = cleanSummary.split('\n');
+        const firstLine = linkifyIssueRefs(summaryLines[0]!, serverUrl, repoSlug);
+
+        // Build the prefix: PR link, commit link, thanks
+        const prefix = formatPrefix(gitInfo, serverUrl, repoSlug, internalAuthorsSet);
+
+        lines.push(`-${prefix ? ` ${prefix} -` : ''} ${firstLine}`);
 
         // Include continuation lines
-        const summaryLines = cs.summary.split('\n');
         for (let i = 1; i < summaryLines.length; i++) {
           if (summaryLines[i]!.trim()) {
-            lines.push(`  ${summaryLines[i]}`);
+            lines.push(`  ${linkifyIssueRefs(summaryLines[i]!, serverUrl, repoSlug)}`);
           }
         }
       }
@@ -60,20 +73,112 @@ export function createGithubFormatter(options: GithubOptions = {}): ChangelogFor
   };
 }
 
-interface PrInfo {
-  number: number;
-  url: string;
-  author: string;
+// ---- Types ----
+
+interface ChangesetGitInfo {
+  prNumber?: number;
+  prUrl?: string;
+  commitHash?: string;
+  author?: string;
+}
+
+interface SummaryOverrides {
+  pr?: number;
+  commit?: string;
+  authors?: string[];
+}
+
+// ---- Metadata extraction from changeset summary ----
+
+/**
+ * Extract metadata lines (pr, commit, author) from a changeset summary.
+ * These override git-derived info, matching the behavior of @changesets/changelog-github.
+ */
+function extractSummaryMeta(summary: string): { cleanSummary: string; overrides: SummaryOverrides } {
+  const overrides: SummaryOverrides = {};
+
+  const cleaned = summary
+    .replace(/^\s*(?:pr|pull|pull\s+request):\s*#?(\d+)/im, (_, pr) => {
+      const num = Number(pr);
+      if (!isNaN(num)) overrides.pr = num;
+      return '';
+    })
+    .replace(/^\s*commit:\s*([^\s]+)/im, (_, commit) => {
+      overrides.commit = commit;
+      return '';
+    })
+    .replace(/^\s*(?:author|user):\s*@?([^\s]+)/gim, (_, user) => {
+      overrides.authors ??= [];
+      overrides.authors.push(user);
+      return '';
+    })
+    .trim();
+
+  return { cleanSummary: cleaned, overrides };
+}
+
+// ---- Git/PR info resolution ----
+
+/**
+ * Resolve PR, commit, and author info for a changeset.
+ * Summary overrides take precedence over git-derived info.
+ */
+function resolveChangesetInfo(
+  changesetId: string,
+  repo: string | undefined,
+  serverUrl: string,
+  overrides: SummaryOverrides,
+): ChangesetGitInfo {
+  // If we have a PR override, look it up directly
+  if (overrides.pr !== undefined) {
+    const prInfo = lookupPr(overrides.pr, repo);
+    return {
+      prNumber: overrides.pr,
+      prUrl: prInfo?.url ?? `${serverUrl}/${repo}/pull/${overrides.pr}`,
+      commitHash: overrides.commit ?? prInfo?.commitHash,
+      author: overrides.authors?.[0] ?? prInfo?.author,
+    };
+  }
+
+  // Otherwise, find the commit that added this changeset file
+  const gitInfo = findChangesetCommitInfo(changesetId, repo);
+
+  return {
+    prNumber: gitInfo?.prNumber,
+    prUrl: gitInfo?.prUrl,
+    commitHash: overrides.commit ?? gitInfo?.commitHash,
+    author: overrides.authors?.[0] ?? gitInfo?.author,
+  };
+}
+
+/** Look up a PR by number using gh CLI */
+function lookupPr(prNumber: number, repo?: string): { url: string; author?: string; commitHash?: string } | null {
+  try {
+    const ghArgs = ['gh', 'pr', 'view', String(prNumber), '--json', 'url,author,mergeCommit'];
+    if (repo) ghArgs.push('--repo', repo);
+
+    const result = tryRunArgs(ghArgs);
+    if (!result) return null;
+
+    const pr = JSON.parse(result);
+    return {
+      url: pr.url,
+      author: pr.author?.login,
+      commitHash: pr.mergeCommit?.oid,
+    };
+  } catch {
+    return null;
+  }
 }
 
 /**
  * Find the PR that introduced a changeset file by checking git log
  * for the commit that added the file, then looking up the PR.
  */
-async function findPrForChangeset(changesetId: string, repo?: string): Promise<PrInfo | null> {
+function findChangesetCommitInfo(changesetId: string, repo?: string): ChangesetGitInfo | null {
   try {
     // Find the commit that added this changeset file
-    const commitHash = tryRunArgs([
+    const commitOutput = tryRunArgs([
       'git',
       'log',
       '--diff-filter=A',
@@ -82,18 +187,18 @@ async function findPrForChangeset(changesetId: string, repo?: string): Promise<P
       `.bumpy/${changesetId}.md`,
       `.changeset/${changesetId}.md`,
     ]);
-    if (!commitHash) return null;
+    if (!commitOutput) return null;
 
-    const hash = commitHash.split('\n')[0]!.trim();
-    if (!hash) return null;
+    const commitHash = commitOutput.split('\n')[0]!.trim();
+    if (!commitHash) return null;
 
     // Look up the PR for this commit
     const ghArgs = [
       'gh',
       'pr',
       'list',
       '--search',
-      hash,
+      commitHash,
       '--state',
       'merged',
       '--json',
@@ -104,17 +209,75 @@ async function findPrForChangeset(changesetId: string, repo?: string): Promise<P
     if (repo) ghArgs.push('--repo', repo);
 
     const prJson = tryRunArgs(ghArgs);
-    if (!prJson) return null;
+    if (!prJson) {
+      return { commitHash };
+    }
 
     const pr = JSON.parse(prJson);
-    if (!pr.number) return null;
+    if (!pr.number) {
+      return { commitHash };
+    }
 
     return {
-      number: pr.number,
-      url: pr.url,
-      author: pr.author?.login || 'unknown',
+      prNumber: pr.number,
+      prUrl: pr.url,
+      commitHash,
+      author: pr.author?.login,
     };
   } catch {
     return null;
   }
 }
+
+// ---- Formatting helpers ----
+
+/**
+ * Build the prefix portion of a changelog line: PR link, commit link, thanks.
+ * Matches the format used by @changesets/changelog-github.
+ */
+function formatPrefix(
+  info: ChangesetGitInfo,
+  serverUrl: string,
+  repo: string | undefined,
+  internalAuthors: Set<string>,
+): string {
+  const parts: string[] = [];
+
+  if (info.prNumber && info.prUrl) {
+    parts.push(`[#${info.prNumber}](${info.prUrl})`);
+  }
+
+  if (info.commitHash && repo) {
+    const short = info.commitHash.slice(0, 7);
+    parts.push(`[\`${short}\`](${serverUrl}/${repo}/commit/${info.commitHash})`);
+  }
+
+  if (info.author && !internalAuthors.has(info.author.toLowerCase())) {
+    parts.push(`Thanks [@${info.author}](${serverUrl}/${info.author})!`);
+  }
+
+  return parts.join(' ');
+}
+
+/**
+ * Linkify bare issue/PR references like #123 in text,
+ * but skip references already inside markdown links.
+ */
+function linkifyIssueRefs(line: string, serverUrl: string, repo?: string): string {
+  if (!repo) return line;
+  // "match what you skip, capture what you want" pattern:
+  // the left alternative consumes markdown links so the right alternative only matches bare refs
+  return line.replace(/\[.*?\]\(.*?\)|\B#([1-9]\d*)\b/g, (match, issue) =>
+    issue ? `[#${issue}](${serverUrl}/${repo}/issues/${issue})` : match,
+  );
+}
+
+/** Try to detect the repo slug from the gh CLI */
+function detectRepo(): string | undefined {
+  try {
+    const result = tryRunArgs(['gh', 'repo', 'view', '--json', 'nameWithOwner', '--jq', '.nameWithOwner']);
+    return result?.trim() || undefined;
+  } catch {
+    return undefined;
+  }
+}

packages/bumpy/src/core/changelog.ts

@@ -87,7 +87,7 @@ export async function loadFormatter(changelog: BumpyConfig['changelog'], rootDir
   // Built-in with options (e.g., ["github", { repo: "..." }])
   if (name === 'github') {
     const { createGithubFormatter } = await import('./changelog-github.ts');
-    return createGithubFormatter(options as Record<string, unknown>);
+    return createGithubFormatter(options as import('./changelog-github.ts').GithubChangelogOptions);
   }
 
   // Custom module

packages/bumpy/src/index.ts

@@ -7,6 +7,7 @@ export { assembleReleasePlan } from './core/release-plan.ts';
 export { applyReleasePlan } from './core/apply-release-plan.ts';
 export { generateChangelogEntry, loadFormatter, defaultFormatter, prependToChangelog } from './core/changelog.ts';
 export type { ChangelogFormatter, ChangelogContext } from './core/changelog.ts';
+export type { GithubChangelogOptions } from './core/changelog-github.ts';
 export { bumpVersion, satisfies, stripProtocol } from './core/semver.ts';
 export { publishPackages } from './core/publish-pipeline.ts';
 export * from './types.ts';