Fix PR comments on forked repositories by using pull_request_target and proper PR number extraction

.github/workflows/commit-check.yml

@@ -1,7 +1,7 @@
 name: Commit Check
 
 on:
- pull_request:
+ pull_request_target:
  branches: 'main'
  workflow_dispatch:
 
@@ -11,14 +11,17 @@ jobs:
  permissions: # use permissions because of use pr-comments
  contents: read
  pull-requests: write
+ issues: write
  steps:
  - uses: actions/checkout@v5
  with:
- ref: ${{ github.event.pull_request.head.sha }} # checkout PR HEAD commit
+ ref: ${{ format('refs/pull/{0}/head', github.event.pull_request.number) }} # checkout PR HEAD commit
  fetch-depth: 0 # fetch all history for all branches and tags
+ persist-credentials: false
  - uses: ./ # self test
  env:
  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # use GITHUB_TOKEN because of use pr-comments
+ GITHUB_PR_NUMBER: ${{ github.event.pull_request.number }} # pass PR number for pull_request_target events
  with:
  message: true
  branch: true
@@ -28,4 +31,4 @@ jobs:
  merge-base: true
  imperative: true
  job-summary: true
- pr-comments: ${{ github.event_name == 'pull_request' }}
+ pr-comments: ${{ github.event_name == 'pull_request' || github.event_name == 'pull_request_target' }}

.gitignore

@@ -1,2 +1,3 @@
 venv/
 .venv/
+__pycache__/

README.md

@@ -27,7 +27,7 @@ name: Commit Check
 
 on:
  push:
- pull_request:
+ pull_request_target:
  branches: 'main'
 
 jobs:
@@ -36,11 +36,13 @@ jobs:
  permissions: # use permissions because use of pr-comments
  contents: read
  pull-requests: write
+ issues: write
  steps:
  - uses: actions/checkout@v4
  with:
- ref: ${{ github.event.pull_request.head.sha }} # checkout PR HEAD commit
+ ref: ${{ format('refs/pull/{0}/head', github.event.pull_request.number) }} # checkout PR HEAD commit
  fetch-depth: 0 # required for merge-base check
+ persist-credentials: false
  - uses: commit-check/commit-check-action@v1
  env:
  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # use GITHUB_TOKEN because use of pr-comments
@@ -53,7 +55,7 @@ jobs:
  merge-base: false
  imperative: false
  job-summary: true
- pr-comments: ${{ github.event_name == 'pull_request' }}
+ pr-comments: ${{ github.event_name == 'pull_request' || github.event_name == 'pull_request_target' }}
 ```
 
 ## Used By
@@ -136,9 +138,7 @@ jobs:
 - Default: `false`
 
 > [!IMPORTANT]
-> `pr-comments` is an experimental feature. By default, it's disabled. To use it, you need to set `GITHUB_TOKEN` in the GitHub Action.
->
-> This feature currently doesn’t work with forked repositories. For more details, refer to issue [#77](https://github.com/commit-check/commit-check-action/issues/77).
+> `pr-comments` is an experimental feature. By default, it's disabled. To use it, you need to set `GITHUB_TOKEN` in the GitHub Action and ensure your workflow has `issues: write` permission.
 
 Note: the default rule of above inputs is following [this configuration](https://github.com/commit-check/commit-check/blob/main/.commit-check.yml). If you want to customize, just add your `.commit-check.yml` config file under your repository root directory.
 

main.py

@@ -25,6 +25,7 @@
 GITHUB_TOKEN = os.getenv("GITHUB_TOKEN")
 GITHUB_REPOSITORY = os.getenv("GITHUB_REPOSITORY")
 GITHUB_REF = os.getenv("GITHUB_REF")
+GITHUB_PR_NUMBER = os.getenv("GITHUB_PR_NUMBER")
 
 
 def log_env_vars():
@@ -116,12 +117,19 @@ def add_pr_comments() -> int:
  try:
  token = os.getenv("GITHUB_TOKEN")
  repo_name = os.getenv("GITHUB_REPOSITORY")
- pr_number = os.getenv("GITHUB_REF")
- if pr_number is not None:
- pr_number = pr_number.split("/")[-2]
- else:
- # Handle the case where GITHUB_REF is not set
- raise ValueError("GITHUB_REF environment variable is not set")
+
+ # Get PR number from GITHUB_PR_NUMBER (for pull_request_target) or extract from GITHUB_REF (for pull_request)
+ pr_number = os.getenv("GITHUB_PR_NUMBER")
+ if pr_number is None:
+ # Fallback to extracting from GITHUB_REF for backward compatibility
+ github_ref = os.getenv("GITHUB_REF")
+ if github_ref is not None:
+ pr_number = github_ref.split("/")[-2]
+ else:
+ # Handle the case where neither environment variable is set
+ raise ValueError(
+ "Neither GITHUB_PR_NUMBER nor GITHUB_REF environment variable is set"
+ )
 
  # Initialize GitHub client
  g = Github(token)