Add test summary to CI (#27648)

Updated our test config to output test summary files. Added a step to the `build` workflow in GitHub actions to read from these files and output a summary in the GitHub UI.

.github/workflows/build.yml

@@ -50,6 +50,12 @@ jobs:
           -DAPP_SECRET="fake_secret" \
           -Duser.timezone=Australia/Sydney \
           -jar ./bin/sbt-launch.jar clean compile assets scalafmtCheckAll test Universal/packageBin
+      
+      - name: Test Summary
+        uses: test-summary/action@v2
+        with:
+          paths: "test-results/**/TEST-*.xml"
+        if: always()
 
       - uses: guardian/actions-riff-raff@v4
         env:

.gitignore

@@ -94,3 +94,4 @@ static/src/stylesheets/pasteup/.npmrc
 metals.sbt
 
 .java-version
+test-results/

project/ProjectSettings.scala

@@ -55,8 +55,7 @@ object ProjectSettings {
   def testStage = if (isCi) "DEVINFRA" else "LOCALTEST"
 
   val frontendTestSettings = Seq(
-    // Use ScalaTest https://groups.google.com/d/topic/play-framework/rZBfNoGtC0M/discussion
-    Test / testOptions := Nil,
+    Test / testOptions += Tests.Argument(TestFrameworks.ScalaTest, "-u", s"test-results/scala-${scalaVersion.value}", "-o"),
     concurrentRestrictions in Global := List(Tags.limit(Tags.Test, 4)),
     // Copy unit test resources https://groups.google.com/d/topic/play-framework/XD3X6R-s5Mc/discussion
     Test / unmanagedClasspath += (baseDirectory map { bd => Attributed.blank(bd / "test") }).value,