git-artifacts: suggest to validate installer in a PR comment

It is currently a bit cumbersome to find the download link to the
installer artifact, and I even missed that it was available for testing
already while the `aarch64` stuff was still being built.

Let's imitate c99c7f2 (release-git(announcement): add a helpful comment,
2025-03-11) and add a helpful PR comment not only when the release
finished, but also when the x86_64 installer was successfully uploaded
and is ready for manual testing.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

.github/workflows/git-artifacts.yml

@@ -470,9 +470,47 @@ jobs:
           cp /usr/src/build-extra/mingit/root/etc/package-versions.txt artifacts/
       - name: Publish ${{matrix.artifact.name}}-${{env.ARCHITECTURE}}
         uses: actions/upload-artifact@v4
+        id: upload-artifact
         with:
           name: ${{matrix.artifact.name}}-${{env.ARCHITECTURE}}
           path: artifacts
+      - uses: actions/create-github-app-token@v1
+        if: matrix.artifact.name == 'installer' && github.event.inputs.architecture == 'x86_64'
+        id: pr-comment-token
+        with:
+          app-id: ${{ secrets.GH_APP_ID }}
+          private-key: ${{ secrets.GH_APP_PRIVATE_KEY }}
+          owner: ${{ env.OWNER }}
+          repositories: ${{ env.REPO }}
+      - name: Add a PR comment suggesting to validate the installer manually
+        if: matrix.artifact.name == 'installer' && github.event.inputs.architecture == 'x86_64'
+        uses: actions/github-script@v7
+        with:
+          github-token: ${{ steps.pr-comment-token.outputs.token }}
+          script: |
+            const installerURL = ${{ toJSON(steps.upload-artifact.outputs.artifact-url) }}
+            const preFlightChecklistURL = 'https://github.com/git-for-windows/build-extra/blob/HEAD/installer/checklist.txt'
+            const body = `## Validate the installer manually
+
+            The [installer](${installerURL}) was built successfully;
+            Please download, install, and run through [the pre-flight check-list](${preFlightChecklistURL}).`
+
+            const fs = require('fs')
+            const gitSHA = fs.readFileSync('bundle-artifacts/git-commit-oid')
+            const q = `repo:${process.env.OWNER}/${process.env.REPO}+is:pr+is:open+${gitSHA}`
+            const { data } = await github.rest.search.issuesAndPullRequests({ q })
+            if (data.items.length !== 1) {
+              core.warning(`${data.items.length} PRs found for ${gitSHA}, not posting a comment, would have posted:\n${body}`)
+            } else {
+              const req = {
+                owner: process.env.OWNER,
+                repo: process.env.REPO,
+                issue_number: data.items[0].number,
+                body: `${body}\n@${data.items[0].user.login} ☝️`,
+              }
+
+              await github.rest.issues.createComment(req)
+            }
       - name: restore check-run state
         if: needs.pkg.outputs.check-run-state != '' && always()
         id: check-run-state