From 8eb48688cd7e6715253d547f3ee79d4092b4aa5d Mon Sep 17 00:00:00 2001
From: Adam Bovill <a@turo.com>
Date: Wed, 13 Sep 2023 22:08:03 +0000
Subject: [PATCH] fix(release-notes-preview): add breaking changes doc check

This adds a new check that enforces that a breaking changes document has been created.
---
 release-notes-preview/action.yaml | 77 +++++++++++++++++++++++++++++--
 1 file changed, 73 insertions(+), 4 deletions(-)

diff --git a/release-notes-preview/action.yaml b/release-notes-preview/action.yaml
index d80b929..6dda702 100644
--- a/release-notes-preview/action.yaml
+++ b/release-notes-preview/action.yaml
@@ -5,6 +5,10 @@ inputs:
     required: true
     description: GitHub token that can checkout the repository as well as create tags/releases against it. e.g. 'secrets.GITHUB_TOKEN'
     default: ${{ github.token }}
+  enforce-breaking-changes-docs:
+    required: false
+    description: Ensure that an appropriate `v<major-version>.md` doc has been created if there are breaking changes in the PR.
+    default: "true"
   extra-plugins:
     required: false
     description: Extra plugins for pre-install. You can also specify specifying version range for the extra plugins if you prefer.  Defaults to install @open-turo/semantic-release-config.
@@ -29,7 +33,7 @@ runs:
         state: open
     - name: Generate release notes
       id: release-notes-preview
-      uses: open-turo/actions-release/semantic-release@v2
+      uses: open-turo/actions-release/semantic-release@add-prerelease-support
       env:
         GITHUB_TOKEN: ${{ inputs.github-token }}
       with:
@@ -37,20 +41,22 @@ runs:
         dry-run: true
         extra-plugins: ${{ inputs.extra-plugins }}
         semantic-version: ${{ inputs.semantic-version }}
+
+    # Add release notes preview to PR
     - name: Check for release notes comment
       uses: peter-evans/find-comment@v2
-      id: fc
+      id: fc-release-notes
       if: steps.find-pull-request.outputs.number != ''
       with:
         issue-number: ${{ steps.find-pull-request.outputs.number }}
         comment-author: "github-actions[bot]"
         body-includes: "<!-- release notes preview comment -->"
     - name: Delete previous release note
-      if: steps.fc.outputs.comment-id != ''
+      if: steps.fc-release-notes.outputs.comment-id != ''
       uses: jungwinter/comment@v1
       with:
         type: delete
-        comment_id: ${{ steps.fc.outputs.comment-id }}
+        comment_id: ${{ steps.fc-release-notes.outputs.comment-id }}
         token: ${{ inputs.github-token }}
     - name: Comment release notes preview
       uses: peter-evans/create-or-update-comment@v1
@@ -76,3 +82,66 @@ runs:
 
           If you are expecting a release, you will need to either fix a bug or add a feature.
           Chores, CI, docs, refactoring, style and other changes will not trigger a release.
+
+    # Ensure that a breaking changes doc has been created
+    - name: Check for breaking changes comment
+      uses: peter-evans/find-comment@v2
+      id: fc-breaking-changes
+      if: steps.find-pull-request.outputs.number != ''
+      with:
+        issue-number: ${{ steps.find-pull-request.outputs.number }}
+        comment-author: "github-actions[bot]"
+        body-includes: "<!-- breaking changes comment -->"
+    - name: Delete previous breaking changes comment
+      if: steps.fc-breaking-changes.outputs.comment-id != ''
+      uses: jungwinter/comment@v1
+      with:
+        type: delete
+        comment_id: ${{ steps.fc-release-notes.outputs.comment-id }}
+        token: ${{ inputs.github-token }}
+    - name: Comment missing breaking changes doc
+      uses: peter-evans/create-or-update-comment@v1
+      if: >
+        steps.release-notes-preview.outputs.new-release-published
+        && inputs.enforce-breaking-changes-docs
+        && steps.release-notes-preview.outputs.new-release-major-version != steps.release-notes-preview.outputs.last-release-major-version
+        && ${{ hashFiles(format(''docs/breaking-changes/v{0}.md', steps.release-notes-preview.outputs.new-release-major-version)) == '' }}
+      with:
+        issue-number: ${{ steps.find-pull-request.outputs.number }}
+        body: |
+          ## Error: missing breaking changes documentation
+          This pull request contains breaking changes, but no documentation has been added to `docs/breaking-changes/v${{ steps.release-notes-preview.outputs.new-release-major-version }}.md`.
+
+          <details>
+            <summary>create doc</summary>
+            ```shell
+            mkdir -p docs/breaking-changes
+            cat <<EOF > docs/breaking-changes/v${{ steps.release-notes-preview.outputs.new-release-major-version }}.md
+            # Breaking changes in v${{ steps.release-notes-preview.outputs.new-release-major-version }}
+
+            [//]: # "Brief description of current major version release scope"
+
+            ## Description of changes
+
+            [//]: # "Elaborate and add context to help the developer understand the changes."
+
+            ## Upgrade instructions
+
+            [//]: # "Required and suggested prerequisites, example code, etc."
+
+            EOF
+            ```
+          </details>
+
+          ---
+          <!-- breaking changes comment -->
+    - name: Fail if we are checking for the breaking changes doc and it is missing
+      if: >
+        steps.release-notes-preview.outputs.new-release-published
+        && inputs.enforce-breaking-changes-docs
+        && steps.release-notes-preview.outputs.new-release-major-version != steps.release-notes-preview.outputs.last-release-major-version
+        && ${{ hashFiles(format(''docs/breaking-changes/v{0}.md', steps.release-notes-preview.outputs.new-release-major-version)) == '' }}
+      shell: bash
+      run: |
+        echo "::error::Breaking changes document is missing. Expected: ``docs/breaking-changes/v${{ steps.release-notes-preview.outputs.new-release-major-version }}.md``"
+        exit 1