Read E2E logs and fail the job if no tests matched the filter

.azure/pipelines/components-e2e-tests.yml

@@ -58,11 +58,35 @@ jobs:
       displayName: Build JS
     - script: .dotnet/dotnet build ./src/Components/test/E2ETest -c $(BuildConfiguration) --no-restore
       displayName: Build
-    - script: .dotnet/dotnet test ./src/Components/test/E2ETest -c $(BuildConfiguration) --no-build --filter 'Quarantined!=true|Quarantined=false'
-                 -p:VsTestUseMSBuildOutput=false
-                 --logger:"trx%3BLogFileName=Microsoft.AspNetCore.Components.E2ETests.trx"
-                 --logger:"html%3BLogFileName=Microsoft.AspNetCore.Components.E2ETests.html"
-                 --results-directory $(Build.SourcesDirectory)/artifacts/TestResults/$(BuildConfiguration)/Unquarantined
+    - script: |
+        set -o pipefail
+
+        .dotnet/dotnet test ./src/Components/test/E2ETest \
+          -c $(BuildConfiguration) \
+          --no-build \
+          --filter 'Quarantined!=true|Quarantined=false' \
+          -p:VsTestUseMSBuildOutput=false \
+          --logger:"trx%3BLogFileName=Microsoft.AspNetCore.Components.E2ETests.trx" \
+          --logger:"html%3BLogFileName=Microsoft.AspNetCore.Components.E2ETests.html" \
+          --results-directory $(Build.SourcesDirectory)/artifacts/TestResults/$(BuildConfiguration)/Unquarantined \
+          | tee e2e-test-output.log
+
+        if grep -q "No test matches the given testcase filter" e2e-test-output.log
+        then
+          echo "##vso[task.logissue type=error] No tests matched the filter."
+
+          exit 1
+        fi
+
+        # Check total tests run to detect abnormalities. In case the number of tests changes significantly, we should adjust the threshold.
+        # Extract total from the summary line "Failed: xx, Passed: yy, Skipped: zz, Total: NNN, Duration: ..."
+        total=$(sed -nE 's/.*Failed:[[:space:]]*[0-9]+,[[:space:]]*Passed:[[:space:]]*[0-9]+,[[:space:]]*Skipped:[[:space:]]*[0-9]+,[[:space:]]*Total:[[:space:]]*([0-9]+).*/\1/p' e2e-test-output.log)
+        min_total=1000
+        if [ -z "$total" ] || [ "$total" -lt "$min_total" ]
+        then
+          echo "##vso[task.logissue type=error] Insufficient total test count: $total. We expect at least $min_total tests to run."
+          exit 1
+        fi
       displayName: Run E2E tests
     - script: .dotnet/dotnet test ./src/Components/test/E2ETest -c $(BuildConfiguration) --no-build --filter 'Quarantined=true' -p:RunQuarantinedTests=true
                  -p:VsTestUseMSBuildOutput=false