devops(bidi): fix publishing when a single csv report is uploaded

.github/workflows/tests_bidi.yml

@@ -60,12 +60,18 @@ jobs:
       run: xvfb-run --auto-servernum --server-args="-screen 0 1280x960x24" -- npm run biditest -- --retries=${{ matrix.isPullRequest && 2 || 0 }} --project=${{ matrix.channel }}*
       env:
         PWTEST_USE_BIDI_EXPECTATIONS: ${{ matrix.isPullRequest && '1' || '' }}
+    # Name the report after the channel so that the publish job can merge all of
+    # them into one directory without collisions.
+    - name: Name the csv report after the channel
+      if: ${{ !cancelled() && hashFiles('test-results/report.csv') != '' }}
+      run: cp test-results/report.csv "$RUNNER_TEMP/${{ matrix.channel }}.csv"
+
     - name: Upload csv report to GitHub
       if: ${{ !cancelled() }}
       uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7.0.1
       with:
         name: csv-report-${{ matrix.channel }}
-        path: test-results/report.csv
+        path: ${{ runner.temp }}/${{ matrix.channel }}.csv
         retention-days: 7
 
     - name: Upload parquet report
@@ -90,21 +96,19 @@ jobs:
       uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
       with:
         pattern: csv-report-*
+        merge-multiple: true
         path: csv-reports
     - name: Publish the reports to the bidi-reports branch
       run: |
         git init -q "$RUNNER_TEMP/reports"
         cd "$RUNNER_TEMP/reports"
         git remote add origin "https://x-access-token:$GITHUB_TOKEN@github.com/$GITHUB_REPOSITORY.git"
-        # Continue the branch history, or start it on the very first run. An
-        # initial commit with no fetched parent is what makes the branch orphan.
-        git fetch --depth=1 origin bidi-reports && git reset --hard FETCH_HEAD || true
-        echo 'Nightly BiDi test reports, published by .github/workflows/tests_bidi.yml.' > README.md
+        git fetch --depth=1 origin bidi-reports
+        git reset --hard FETCH_HEAD
         channels=()
-        for dir in "$GITHUB_WORKSPACE"/csv-reports/csv-report-*/; do
-          channel=${dir%/}
-          channel=${channel##*/csv-report-}
-          cp "$dir/report.csv" "$channel.csv"
+        for file in "$GITHUB_WORKSPACE"/csv-reports/*.csv; do
+          channel=$(basename "$file" .csv)
+          cp "$file" "$channel.csv"
           channels+=("$channel")
         done
         git add -A