scalatestsuite: Collect and output logs for failing tests

This patch introduces a new feature of the `UnitTestSuite`:

  When tests are ran we collect logs for the `no.ndla` package in a
  buffer, and when a test fails the collected logs are printed for that
  test in particular.

  This allows us to keep clean and readable logs when tests are green,
  but will allow us to more easily find mistakes when a test fails.

Author: jnatten

common/src/main/scala/no/ndla/common/model/NDLADate.scala

@@ -55,7 +55,7 @@ case class NDLADate(underlying: ZonedDateTime) extends Ordered[NDLADate] {
   }
 }
 
-object NDLADate {
+object NDLADate extends StrictLogging {
 
   implicit val typescriptType: TSType[NDLADate] = TSType.sameAs[NDLADate, String]
 

draft-api/src/test/scala/no/ndla/draftapi/integration/TaxonomyApiClientTest.scala

@@ -22,7 +22,7 @@ class TaxonomyApiClientTest extends UnitSuite with TestEnvironment {
 
   override val taxonomyApiClient: TaxonomyApiClient = spy(new TaxonomyApiClient)
 
-  override protected def beforeEach(): Unit = {
+  override def beforeEach(): Unit = {
     // Since we use spy, we reset the mock before each test allowing verify to be accurate
     reset(taxonomyApiClient)
   }

log4j2-test.yaml

@@ -1,5 +1,8 @@
 Configuration:
   status: warn
   Loggers:
+    Logger:
+      name: "no.ndla"
+      level: debug
     Root:
       level: warn

project/scalatestsuitelib.scala

@@ -6,12 +6,17 @@ import sbt.Keys.*
 object scalatestsuitelib extends Module {
   override val moduleName: String      = "scalatestsuite"
   override val enableReleases: Boolean = false
-  lazy val dependencies: Seq[ModuleID] = Seq(
-    "org.scalatest"     %% "scalatest"      % ScalaTestV,
-    "org.testcontainers" % "elasticsearch"  % TestContainersV,
-    "org.testcontainers" % "testcontainers" % TestContainersV,
-    "org.testcontainers" % "postgresql"     % TestContainersV
-  ) ++ database ++ vulnerabilityOverrides ++ mockito
+  lazy val dependencies: Seq[ModuleID] = withLogging(
+    Seq(
+      "org.scalatest"     %% "scalatest"      % ScalaTestV,
+      "org.testcontainers" % "elasticsearch"  % TestContainersV,
+      "org.testcontainers" % "testcontainers" % TestContainersV,
+      "org.testcontainers" % "postgresql"     % TestContainersV
+    ),
+    database,
+    vulnerabilityOverrides,
+    mockito
+  )
 
   override lazy val settings: Seq[Def.Setting[?]] = Seq(
     libraryDependencies ++= dependencies

scalatestsuite/src/main/scala/no/ndla/scalatestsuite/BufferedLogAppender.scala

@@ -0,0 +1,39 @@
+/*
+ * Part of NDLA backend.scalatestsuite.main
+ * Copyright (C) 2025 NDLA
+ *
+ * See LICENSE
+ *
+ */
+
+package no.ndla.scalatestsuite
+
+import org.apache.logging.log4j.core.LogEvent
+import org.apache.logging.log4j.core.appender.AbstractAppender
+import org.apache.logging.log4j.core.layout.PatternLayout
+
+import scala.collection.mutable.ListBuffer
+
+object Layout {
+  lazy val prebuiltLayout: PatternLayout = PatternLayout
+    .newBuilder()
+    .withPattern("[%level] %C.%M#%L: %msg%n")
+    .build()
+}
+
+class BufferedLogAppender
+    extends AbstractAppender("BufferedAppender", null, Layout.prebuiltLayout, false, Array.empty) {
+  private val logQueue  = ListBuffer.empty[String]
+  def clear(): Unit     = logQueue.clear()
+  def printLogs(): Unit = logQueue.foreach(print)
+  def getAndClearLogs: List[String] = {
+    val toReturn = logQueue.toList
+    logQueue.clear()
+    toReturn
+  }
+
+  override def append(event: LogEvent): Unit = {
+    val logString = getLayout.toSerializable(event).toString
+    logQueue.append(logString)
+  }
+}

scalatestsuite/src/main/scala/no/ndla/scalatestsuite/ColoredText.scala

@@ -0,0 +1,27 @@
+/*
+ * Part of NDLA scalatestsuite
+ * Copyright (C) 2025 NDLA
+ *
+ * See LICENSE
+ *
+ */
+
+package no.ndla.scalatestsuite
+
+object ColoredText {
+  val RED    = "\u001b[31m"
+  val GREEN  = "\u001b[32m"
+  val YELLOW = "\u001b[33m"
+  val BLUE   = "\u001b[34m"
+  val RESET  = "\u001b[0m"
+
+  def print(color: Colors, text: String) = {
+    color match {
+      case Red    => println(s"$RED$text$RESET")
+      case Green  => println(s"$GREEN$text$RESET")
+      case Yellow => println(s"$YELLOW$text$RESET")
+      case Blue   => println(s"$BLUE$text$RESET")
+    }
+  }
+
+}

scalatestsuite/src/main/scala/no/ndla/scalatestsuite/Colors.scala

@@ -0,0 +1,15 @@
+/*
+ * Part of NDLA scalatestsuite
+ * Copyright (C) 2025 NDLA
+ *
+ * See LICENSE
+ *
+ */
+
+package no.ndla.scalatestsuite
+
+sealed trait Colors
+case object Red    extends Colors
+case object Green  extends Colors
+case object Yellow extends Colors
+case object Blue   extends Colors

scalatestsuite/src/main/scala/no/ndla/scalatestsuite/IntegrationSuite.scala

@@ -149,8 +149,13 @@ abstract class IntegrationSuite(
     })
   }
 
-  override def beforeAll(): Unit = setDatabaseEnvironment()
+  override def beforeAll(): Unit = {
+    super.beforeAll()
+    setDatabaseEnvironment()
+  }
+
   override def afterAll(): Unit = {
+    super.afterAll()
     setPropEnv(previousDatabaseEnv)
     elasticSearchContainer.foreach(c => c.stop())
     postgresContainer.foreach(c => c.stop())

scalatestsuite/src/main/scala/no/ndla/scalatestsuite/TestSuiteLoggingSetup.scala

@@ -0,0 +1,66 @@
+/*
+ * Part of NDLA backend.scalatestsuite.main
+ * Copyright (C) 2025 NDLA
+ *
+ * See LICENSE
+ *
+ */
+
+package no.ndla.scalatestsuite
+
+import org.apache.logging.log4j.core.LoggerContext
+import org.apache.logging.log4j.{Level, LogManager}
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.{BeforeAndAfterAll, BeforeAndAfterEach, Outcome}
+
+import scala.collection.mutable.ListBuffer
+
+/** Sets up test environment to keep logs and print them if the test fails */
+trait TestSuiteLoggingSetup extends AnyFunSuite with BeforeAndAfterEach with BeforeAndAfterAll {
+  private val appender      = new BufferedLogAppender()
+  private def getNDLALogger = LogManager.getContext(false).asInstanceOf[LoggerContext].getLogger("no.ndla")
+  private val beforeAllLog  = ListBuffer.empty[String]
+
+  private def setupLogger(): Unit = {
+    if (!appender.isStarted) appender.start()
+    val ndlaLogger = getNDLALogger
+    ndlaLogger.setLevel(Level.DEBUG)
+    ndlaLogger.addAppender(appender)
+  }
+
+  override def beforeEach(): Unit = {
+    val logs = appender.getAndClearLogs
+    beforeAllLog.addAll(logs)
+    setupLogger()
+    super.beforeEach()
+  }
+
+  override def beforeAll(): Unit = {
+    setupLogger()
+    super.beforeAll()
+  }
+
+  override def afterEach(): Unit = {
+    val ndlaLogger = getNDLALogger
+    ndlaLogger.removeAppender(appender)
+    appender.clear()
+    super.afterEach()
+  }
+
+  override def withFixture(test: NoArgTest): Outcome = {
+    val result = super.withFixture(test)
+    if (!result.isSucceeded) {
+      // If test fails, print the buffered logs
+      val testName = s"${this.suiteName}$$'${test.name}'"
+      ColoredText.print(Red, s"\n---- Captured Logs for test: $testName ----")
+      if (beforeAllLog.nonEmpty) {
+        ColoredText.print(Red, s">>> Captured Logs from $suiteName$$beforeAll: >>>")
+        beforeAllLog.foreach(print)
+        ColoredText.print(Red, s"<<< End of Captured Logs from $suiteName$$beforeAll <<<")
+      }
+      appender.printLogs()
+      ColoredText.print(Red, s"---- End of Captured Logs for test: $testName ----\n")
+    }
+    result
+  }
+}

scalatestsuite/src/main/scala/no/ndla/scalatestsuite/UnitTestSuite.scala

@@ -7,15 +7,15 @@
 
 package no.ndla.scalatestsuite
 
-import org.scalatestplus.mockito.MockitoSugar
-import org.scalatest._
+import org.scalatest.*
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers
+import org.scalatestplus.mockito.MockitoSugar
 
 import java.io.IOException
 import java.net.ServerSocket
 import scala.util.Properties.{propOrNone, setProp}
-import scala.util.{Try, Success, Failure}
+import scala.util.{Failure, Success, Try}
 
 abstract class UnitTestSuite
     extends AnyFunSuite
@@ -25,7 +25,8 @@ abstract class UnitTestSuite
     with Inspectors
     with MockitoSugar
     with BeforeAndAfterEach
-    with BeforeAndAfterAll {
+    with BeforeAndAfterAll
+    with TestSuiteLoggingSetup {
 
   def setPropEnv(key: String, value: String): String = setProp(key, value)