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

[Jiang Xin <worldhello.net@gmail.com>]

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

Git l10n 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 message. It would be convenient to integrate
this helper program to CI and add comments in pull request.

The new github-action workflow is added in ".github/workflows/l10n.yml",
which is disabled by default. To turn it on for the git-l10n related
repositories, such as "git-l10n/git-po", we can add a new branch named
"ci-config" and create a simple shell script at "ci/config/allow-l10n"
in this branch.

The new l10n workflow listens to two types of github events: push and
pull_request.

For a push event, it will scan commits one by one. If a commit does not
look like a l10n commit (no file in "po/" has been changed), it will
immediately fail without checking for further commits. While for a
pull_request event, all new introduced commits will be scanned.

"git-po-helper" will generate two kinds of suggestions, errors and
warnings. A l10n contributor should try to fix all the errors, and
should pay attention to the warnings. All the errors and warnings will
be reported in the last step of the l10n workflow as two message groups.
For a pull_request event, will create additional comments in pull
request to report the result.

Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
---
 .github/workflows/l10n.yml | 143 +++++++++++++++++++++++++++++++++++++
 1 file changed, 143 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 0000000000..60f162c121
--- /dev/null
+++ b/.github/workflows/l10n.yml
@@ -0,0 +1,143 @@
+name: git-l10n
+
+on: [push, pull_request]
+
+jobs:
+  ci-config:
+    runs-on: ubuntu-latest
+    outputs:
+      enabled: ${{ steps.check-l10n.outputs.enabled }}
+    steps:
+      - name: try to clone ci-config branch
+        run: |
+          git -c protocol.version=2 clone \
+            --no-tags \
+            --single-branch \
+            -b ci-config \
+            --depth 1 \
+            --no-checkout \
+            --filter=blob:none \
+            https://github.com/${{ github.repository }} \
+            config-repo &&
+          cd config-repo &&
+          git checkout HEAD -- ci/config || : ignore
+      - id: check-l10n
+        name: check whether CI is enabled for l10n
+        run: |
+          enabled=no
+          if test -x config-repo/ci/config/allow-l10n &&
+             config-repo/ci/config/allow-l10n '${{ github.ref }}'
+          then
+            enabled=yes
+          fi
+          echo "::set-output name=enabled::$enabled"
+
+  git-po-helper:
+    needs: ci-config
+    if: needs.ci-config.outputs.enabled == 'yes'
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: '0'
+    - 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
+    - id: check-commits
+      name: Run git-po-helper
+      run: |
+        if test "${{ github.event_name }}" = "pull_request"
+        then
+          commit_from=${{ github.event.pull_request.base.sha }}
+          commit_to=${{ github.event.pull_request.head.sha }}
+        else
+          commit_from=${{ github.event.before }}
+          commit_to=${{ github.event.after }}
+          if ! echo $commit_from | grep -q "^00*$"
+          then
+            if ! git rev-parse "$commit_from^{commit}"
+            then
+              git fetch origin $commit_from
+            fi
+          fi
+        fi
+        exit_code=0
+        git-po-helper check-commits --github-action -- \
+          $commit_from..$commit_to >git-po-helper.out 2>&1 ||
+        exit_code=$?
+        echo "::set-output name=exit_code::$exit_code"
+        has_error_msg=
+        has_warning_msg=
+        if test $exit_code -ne 0
+        then
+          has_error_msg=yes
+          if test "${{ github.event_name }}" = "pull_request"
+          then
+            echo "ERROR_MSG<<EOF" >>$GITHUB_ENV
+            grep -v -e "^level=warning" -e WARNING git-po-helper.out |
+              perl -pe 's/\e\[[0-9;]*m//g' >>$GITHUB_ENV
+            echo "EOF" >>$GITHUB_ENV
+          fi
+        fi
+        if grep -q -e "^level=warning" -e WARNING git-po-helper.out
+        then
+          has_warning_msg=yes
+          if test "${{ github.event_name }}" = "pull_request"
+          then
+            echo "WARNING_MSG<<EOF" >>$GITHUB_ENV
+            grep -v -e "^level=error" -e ERROR git-po-helper.out |
+              perl -pe 's/\e\[[0-9;]*m//g' >>$GITHUB_ENV
+            echo "EOF" >>$GITHUB_ENV
+          fi
+        fi
+        echo "::set-output name=has_error_msg::$has_error_msg"
+        echo "::set-output name=has_warning_msg::$has_warning_msg"
+    - name: Report errors in comment for pull request
+      uses: mshick/add-pr-comment@v1
+      if: steps.check-commits.outputs.has_error_msg == 'yes' && github.event_name == 'pull_request'
+      continue-on-error: true
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        repo-token-user-login: 'github-actions[bot]'
+        message: |
+          Errors found by git-po-helper in workflow ${{ github.workflow }}:
+          ```
+          ${{ env.ERROR_MSG }}
+          ```
+    - name: Report warnings in comment for pull request
+      uses: mshick/add-pr-comment@v1
+      if: steps.check-commits.outputs.has_warning_msg == 'yes' && github.event_name == 'pull_request'
+      continue-on-error: true
+      with:
+        repo-token: ${{ secrets.GITHUB_TOKEN }}
+        repo-token-user-login: 'github-actions[bot]'
+        message: |
+          Warnings found by git-po-helper in workflow ${{ github.workflow }}:
+          ```
+          ${{ env.WARNING_MSG }}
+          ```
+    - name: Report and quit
+      run: |
+        if test "${{ steps.check-commits.outputs.has_error_msg }}" = "yes"
+        then
+          echo "::group::Errors found by git-po-helper"
+          grep -v -e "^level=warning" -e WARNING git-po-helper.out
+          echo "::endgroup::"
+        fi
+        if test "${{ steps.check-commits.outputs.has_warning_msg }}" = "yes"
+        then
+          echo "::group::Warnings found by git-po-helper"
+          grep -v -e "^level=error" -e ERROR git-po-helper.out
+          echo "::endgroup::"
+        fi
+        if test ${{ steps.check-commits.outputs.exit_code }} -ne 0
+        then
+          exit ${{ steps.check-commits.outputs.exit_code }}
+        fi
-- 
2.33.0