feat: add automated PR comments on release

.github/comment-on-release/README.md

@@ -0,0 +1,83 @@
+# Comment on Release Action
+
+A reusable GitHub Action that automatically comments on PRs when they are included in a release.
+
+## What It Does
+
+When packages are published via Changesets:
+
+1. Parses each published package's CHANGELOG to find PR numbers in the latest version
+2. Groups PRs by number (handling cases where one PR affects multiple packages)
+3. Posts a comment on each PR with release info and CHANGELOG links
+
+## Example Comment
+
+```
+🎉 This PR has been released!
+
+- [@tanstack/query-core@5.0.0](https://github.com/TanStack/query/blob/main/packages/query-core/CHANGELOG.md#500)
+- [@tanstack/react-query@5.0.0](https://github.com/TanStack/query/blob/main/packages/react-query/CHANGELOG.md#500)
+
+Thank you for your contribution!
+```
+
+## Usage
+
+Add this step to your `.github/workflows/release.yml` file after the `changesets/action` step:
+
+```yaml
+- name: Run Changesets (version or publish)
+  id: changesets
+  uses: changesets/action@v1.5.3
+  with:
+    version: pnpm run changeset:version
+    publish: pnpm run changeset:publish
+    commit: 'ci: Version Packages'
+    title: 'ci: Version Packages'
+  env:
+    GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+    NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
+
+- name: Comment on PRs about release
+  if: steps.changesets.outputs.published == 'true'
+  uses: tanstack/config/.github/comment-on-release@main
+  with:
+    published-packages: ${{ steps.changesets.outputs.publishedPackages }}
+```
+
+## Requirements
+
+- Must be using [Changesets](https://github.com/changesets/changesets) for releases
+- CHANGELOGs must include PR links in the format: `[#123](https://github.com/org/repo/pull/123)`
+- Requires `pull-requests: write` permission in the workflow
+- The `gh` CLI must be available (automatically available in GitHub Actions)
+
+## Inputs
+
+| Input                | Required | Description                                                        |
+| -------------------- | -------- | ------------------------------------------------------------------ |
+| `published-packages` | Yes      | JSON string of published packages from `changesets/action` outputs |
+
+## How It Works
+
+The action:
+
+1. Receives the list of published packages from the Changesets action
+2. For each package, reads its CHANGELOG at `packages/{package-name}/CHANGELOG.md`
+3. Extracts PR numbers from the latest version section using regex
+4. Groups all PRs and tracks which packages they contributed to
+5. Posts a single comment per PR listing all packages it was released in
+6. Uses the `gh` CLI to post comments via the GitHub API
+
+## Troubleshooting
+
+**No comments are posted:**
+
+- Verify your CHANGELOGs have PR links in the correct format
+- Check that `steps.changesets.outputs.published` is `true`
+- Ensure the workflow has `pull-requests: write` permission
+
+**Script fails to find CHANGELOGs:**
+
+- The script expects packages at `packages/{package-name}/CHANGELOG.md`
+- Package name should match after removing the scope (e.g., `@tanstack/query-core` → `query-core`)

.github/comment-on-release/action.yml

@@ -0,0 +1,15 @@
+name: Comment on PRs about release
+description: Automatically comments on PRs when they are included in a release
+inputs:
+  published-packages:
+    description: 'JSON string of published packages from changesets/action'
+    required: true
+runs:
+  using: composite
+  steps:
+    - name: Comment on PRs
+      shell: bash
+      env:
+        PUBLISHED_PACKAGES: ${{ inputs.published-packages }}
+        REPOSITORY: ${{ github.repository }}
+      run: node {{ github.action_path }}/comment-on-release.ts

.github/comment-on-release/comment-on-release.ts

@@ -0,0 +1,184 @@
+#!/usr/bin/env node
+
+import { readFileSync } from 'node:fs'
+import { resolve } from 'node:path'
+import { execSync } from 'node:child_process'
+
+interface PublishedPackage {
+  name: string
+  version: string
+}
+
+interface PRInfo {
+  number: number
+  packages: Array<{ name: string; pkgPath: string; version: string }>
+}
+
+/**
+ * Parse CHANGELOG.md to extract PR numbers from the latest version entry
+ */
+function extractPRsFromChangelog(
+  changelogPath: string,
+  version: string,
+): Array<number> {
+  try {
+    const content = readFileSync(changelogPath, 'utf-8')
+    const lines = content.split('\n')
+
+    let inTargetVersion = false
+    let foundVersion = false
+    const prNumbers = new Set<number>()
+
+    for (let i = 0; i < lines.length; i++) {
+      const line = lines[i]
+
+      // Check for version header (e.g., "## 0.21.0")
+      if (line.startsWith('## ')) {
+        const versionMatch = line.match(/^## (\d+\.\d+\.\d+)/)
+        if (versionMatch) {
+          if (versionMatch[1] === version) {
+            inTargetVersion = true
+            foundVersion = true
+          } else if (inTargetVersion) {
+            // We've moved to the next version, stop processing
+            break
+          }
+        }
+      }
+
+      // Extract PR numbers from links like [#302](https://github.com/TanStack/config/pull/302)
+      if (inTargetVersion) {
+        const prMatches = line.matchAll(
+          /\[#(\d+)\]\(https:\/\/github\.com\/[^/]+\/[^/]+\/pull\/\d+\)/g,
+        )
+        for (const match of prMatches) {
+          prNumbers.add(parseInt(match[1], 10))
+        }
+      }
+    }
+
+    if (!foundVersion) {
+      console.warn(
+        `Warning: Could not find version ${version} in ${changelogPath}`,
+      )
+    }
+
+    return Array.from(prNumbers)
+  } catch (error) {
+    console.error(`Error reading changelog at ${changelogPath}:`, error)
+    return []
+  }
+}
+
+/**
+ * Group PRs by their numbers and collect all packages they contributed to
+ */
+function groupPRsByNumber(
+  publishedPackages: Array<PublishedPackage>,
+): Map<number, PRInfo> {
+  const prMap = new Map<number, PRInfo>()
+
+  for (const pkg of publishedPackages) {
+    const pkgPath = `packages/${pkg.name.replace('@tanstack/', '')}`
+    const changelogPath = resolve(process.cwd(), pkgPath, 'CHANGELOG.md')
+
+    const prNumbers = extractPRsFromChangelog(changelogPath, pkg.version)
+
+    for (const prNumber of prNumbers) {
+      if (!prMap.has(prNumber)) {
+        prMap.set(prNumber, { number: prNumber, packages: [] })
+      }
+      prMap.get(prNumber)!.packages.push({
+        name: pkg.name,
+        pkgPath: pkgPath,
+        version: pkg.version,
+      })
+    }
+  }
+
+  return prMap
+}
+
+/**
+ * Post a comment on a GitHub PR using gh CLI
+ */
+async function commentOnPR(pr: PRInfo, repository: string): Promise<void> {
+  const { number, packages } = pr
+
+  // Build the comment body
+  let comment = `🎉 This PR has been released!\n\n`
+
+  for (const pkg of packages) {
+    // Link to the package's changelog and version anchor
+    const changelogUrl = `https://github.com/${repository}/blob/main/${pkg.pkgPath}/CHANGELOG.md#${pkg.version.replaceAll('.', '')}`
+    comment += `- [${pkg.name}@${pkg.version}](${changelogUrl})\n`
+  }
+
+  comment += `\nThank you for your contribution!`
+
+  try {
+    // Use gh CLI to post the comment
+    execSync(`gh pr comment ${number} --body ${JSON.stringify(comment)}`, {
+      stdio: 'inherit',
+    })
+    console.log(`✓ Commented on PR #${number}`)
+  } catch (error) {
+    console.error(`✗ Failed to comment on PR #${number}:`, error)
+  }
+}
+
+/**
+ * Main function
+ */
+async function main() {
+  // Read published packages from environment variable (set by GitHub Actions)
+  const publishedPackagesJson = process.env.PUBLISHED_PACKAGES
+  const repository = process.env.REPOSITORY
+
+  if (!publishedPackagesJson) {
+    console.log('No packages were published. Skipping PR comments.')
+    return
+  }
+
+  if (!repository) {
+    console.log('Repository is missing. Skipping PR comments.')
+    return
+  }
+
+  let publishedPackages: Array<PublishedPackage>
+  try {
+    publishedPackages = JSON.parse(publishedPackagesJson)
+  } catch (error) {
+    console.error('Failed to parse PUBLISHED_PACKAGES:', error)
+    process.exit(1)
+  }
+
+  if (publishedPackages.length === 0) {
+    console.log('No packages were published. Skipping PR comments.')
+    return
+  }
+
+  console.log(`Processing ${publishedPackages.length} published package(s)...`)
+
+  // Group PRs by number
+  const prMap = groupPRsByNumber(publishedPackages)
+
+  if (prMap.size === 0) {
+    console.log('No PRs found in CHANGELOGs. Nothing to comment on.')
+    return
+  }
+
+  console.log(`Found ${prMap.size} PR(s) to comment on...`)
+
+  // Comment on each PR
+  for (const pr of prMap.values()) {
+    await commentOnPR(pr, repository)
+  }
+
+  console.log('✓ Done!')
+}
+
+main().catch((error) => {
+  console.error('Fatal error:', error)
+  process.exit(1)
+})

.github/workflows/release.yml

@@ -31,6 +31,7 @@ jobs:
       - name: Run Tests
         run: pnpm run test:ci
       - name: Run Changesets (version or publish)
+        id: changesets
         uses: changesets/action@v1.5.3
         with:
           version: pnpm run changeset:version
@@ -40,3 +41,8 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
+      - name: Comment on PRs about release
+        if: steps.changesets.outputs.published == 'true'
+        uses: ./.github/comment-on-release
+        with:
+          published-packages: ${{ steps.changesets.outputs.publishedPackages }}