[PATCH v4 1/1] ci: new github-action for git-l10n code review

From: Jiang Xin <worldhello.net@gmail.com>
Date: Sep 2, 2021, 02:31 UTC
Message-ID: <20210902023139.89251-2-worldhello.net@gmail.com>
In-Reply-To: <CANYiYbESO7bvyuRcypmVKvqAdLk5492q5fUPu5ArdCY5PHzFSQ@mail.gmail.com>

From: Jiang Xin <zhiyou.jx@alibaba-inc.com>

The repository of git-l10n is a fork of "git/git" on GitHub, and uses GitHub pull request for code review. A helper program "git-po-helper" can be used to check typos in ".po" files, validate syntax, and check commit messages. It would be convenient to integrate this helper program to CI and add comments in pull request.

The new github-action workflow will be enabled for l10n related operations, such as:

 * Operations on a repository named as "git-po", such as a repository
   forked from "git-l10n/git-po".

 * Push to a branch that contains "l10n" in the name.

 * Pull request from a remote branch which has "l10n" in the name, such
   as: "l10n/fix-fuzzy-translations".

The new l10n workflow listens to two types of github events:

    on: [push, pull_request_target]

The reason we use "pull_request_target" instead of "pull_request" is that pull requests from forks receive a read-only GITHUB_TOKEN and workflows cannot write comments back to pull requests for security reasons. GitHub provides a "pull_request_target" event to resolve security risks by checking out the base commit from the target repository, and provide write permissions for the workflow.

By default, administrators can set strict permissions for workflows. The following code is used to modify the permissions for the GITHUB_TOKEN and grant write permission in order to create comments in pull-requests.

    permissions:
      pull-requests: write

This workflow will scan commits one by one. If a commit does not look like a l10n commit (no file in "po/" has been changed), the scan process will stop immediately. For a "push" event, no error will be reported because it is normal to push non-l10n commits merged from upstream. But for the "pull_request_target" event, errors will be reported. For this reason, additional option is provided for "git-po-helper".

    git-po-helper check-commits \
        --github-action-event="${{ github.event_name }}" -- \
        <base>..<head>

The output messages of "git-po-helper" contain color codes not only for console, but also for logfile. This is because "git-po-helper" uses a package named "logrus" for logging, and I use an additional option "ForceColor" to initialize "logrus" to print messages in a user-friendly format in logfile output. These color codes help produce beautiful output for the log of workflow, but they must be stripped off when creating comments for pull requests. E.g.:

    perl -pe 's/\e\[[0-9;]*m//g' git-po-helper.out

"git-po-helper" may generate two kinds of suggestions, errors and warnings. All the errors and warnings will be reported in the log of the l10n workflow. However, warnings in the log of the workflow for a successfully running "git-po-helper" can easily be ignored by users. For the "pull_request_target" event, this issue is resolved by creating an additional comment in the pull request. A l10n contributor should try to fix all the errors, and should pay attention to the warnings.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
---
 .github/workflows/l10n.yml | 93 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 .github/workflows/l10n.yml

diff --git a/.github/workflows/l10n.yml b/.github/workflows/l10n.yml
new file mode 100644
index 0000000..7e2385d
--- /dev/null
+++ b/.github/workflows/l10n.yml
@@ -0,0 +1,93 @@
+name: git-l10n
+
+on: [push, pull_request_target]
+
+jobs:
+  git-po-helper:
+    if: >-
+      endsWith(github.repository, '/git-po') ||
+      contains(github.head_ref, 'l10n') ||
+      contains(github.ref, 'l10n')
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: '1'
+      - name: Fetch missing commits
+        id: fetch-commits
+        run: |
+          if test "${{ github.event_name }}" = "pull_request_target"
+          then
+            base=${{ github.event.pull_request.base.sha }}
+            head=${{ github.event.pull_request.head.sha }}
+          else
+            base=${{ github.event.before }}
+            head=${{ github.event.after }}
+          fi
+          args=
+          for commit in $base $head
+          do
+            case $commit in
+            *[^0]*)
+              args="$args $commit"
+              ;;
+            *)
+              # Ignore ZERO-OID.
+              ;;
+            esac
+          done
+          # Unshallow the repository, and fetch missing commits using partial
+          # clone.  "$base" may be missing due to forced push, and "$head"
+          # may be missing due to the "pull_request_target" event.
+          git fetch --unshallow --filter=blob:none origin $args
+          echo "::set-output name=base::$base"
+          echo "::set-output name=head::$head"
+      - uses: actions/setup-go@v2
+        with:
+          go-version: '>=1.16'
+      - name: Install git-po-helper
+        run: go install github.com/git-l10n/git-po-helper@main
+      - name: Install other dependencies
+        run: |
+          sudo apt-get update -q &&
+          sudo apt-get install -q -y gettext
+      - name: Run git-po-helper
+        id: check-commits
+        run: |
+          exit_code=0
+          git-po-helper check-commits \
+              --github-action-event="${{ github.event_name }}" -- \
+              ${{ steps.fetch-commits.outputs.base }}..${{ steps.fetch-commits.outputs.head }} \
+              >git-po-helper.out 2>&1 ||
+            exit_code=$?
+          if test $exit_code -ne 0 || grep -q WARNING git-po-helper.out
+          then
+            # Remove ANSI colors which are proper for console logs but not
+            # proper for PR comment.
+            echo "COMMENT_BODY<<EOF" >>$GITHUB_ENV
+            perl -pe 's/\e\[[0-9;]*m//g; s/\bEOF$//g' git-po-helper.out >>$GITHUB_ENV
+            echo "EOF" >>$GITHUB_ENV
+          fi
+          cat git-po-helper.out
+          exit $exit_code
+      - name: Create comment in pull request for report
+        uses: mshick/add-pr-comment@v1
+        if: >-
+          always() &&
+          github.event_name == 'pull_request_target' &&
+          env.COMMENT_BODY != ''
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          repo-token-user-login: 'github-actions[bot]'
+          message: >
+            ${{ steps.check-commits.outcome == 'failure' && 'Errors and warnings' || 'Warnings' }}
+            found by [git-po-helper](https://github.com/git-l10n/git-po-helper#readme) in workflow
+            [#${{ github.run_number }}](${{ env.GITHUB_SERVER_URL }}/${{ github.repository }}/actions/runs/${{ github.run_id }}):
+
+            ```
+
+            ${{ env.COMMENT_BODY }}
+
+            ```

-- 
2.33.0