RandomSeedTestRule.kt added

Author: dconeybe

firebase-dataconnect/androidTestutil/androidTestutil.gradle.kts

@@ -58,6 +58,7 @@ dependencies {
   implementation(libs.androidx.test.core)
   implementation(libs.androidx.test.junit)
   implementation(libs.auth0.jwt)
+  implementation(libs.kotest.property)
   implementation(libs.kotlinx.coroutines.core)
   implementation(libs.kotlinx.serialization.core)
   implementation(libs.kotlinx.serialization.json)

firebase-dataconnect/androidTestutil/src/main/kotlin/com/google/firebase/dataconnect/testutil/DataConnectIntegrationTestBase.kt

@@ -19,6 +19,7 @@ package com.google.firebase.dataconnect.testutil
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import com.google.firebase.dataconnect.ConnectorConfig
 import com.google.firebase.util.nextAlphanumericString
+import io.kotest.property.RandomSource
 import kotlin.random.Random
 import org.junit.Rule
 import org.junit.rules.TestName
@@ -35,6 +36,10 @@ abstract class DataConnectIntegrationTestBase {
 
   @get:Rule val dataConnectFactory = TestDataConnectFactory(firebaseAppFactory)
 
+  @get:Rule(order = Int.MIN_VALUE) val randomSeedTestRule = RandomSeedTestRule()
+
+  val rs: RandomSource by randomSeedTestRule.rs
+
   companion object {
     val testConnectorConfig: ConnectorConfig
       get() =

firebase-dataconnect/src/androidTest/kotlin/com/google/firebase/dataconnect/AuthIntegrationTest.kt

@@ -41,7 +41,6 @@ import io.kotest.matchers.collections.shouldNotContainNull
 import io.kotest.matchers.nulls.shouldNotBeNull
 import io.kotest.matchers.shouldBe
 import io.kotest.property.Arb
-import io.kotest.property.RandomSource
 import io.kotest.property.arbitrary.next
 import java.util.concurrent.CopyOnWriteArrayList
 import kotlin.random.Random
@@ -60,7 +59,6 @@ import org.junit.runner.RunWith
 class AuthIntegrationTest : DataConnectIntegrationTestBase() {
 
   private val key = "e6w33rw36t"
-  private val rs = RandomSource.default()
 
   @get:Rule val inProcessDataConnectGrpcServer = InProcessDataConnectGrpcServer()
 

firebase-dataconnect/testutil/src/main/kotlin/com/google/firebase/dataconnect/testutil/RandomSeedTestRule.kt

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.firebase.dataconnect.testutil
+
+import io.kotest.property.RandomSource
+import org.junit.rules.TestRule
+import org.junit.runner.Description
+import org.junit.runners.model.Statement
+
+/**
+ * A JUnit test rule that prints the seed of a [RandomSource] if the test fails, enabling replaying
+ * the test with the same seed to investigate failures. If the [Lazy] is never initialized, then the
+ * random seed is _not_ printed.
+ */
+class RandomSeedTestRule(val rs: Lazy<RandomSource>) : TestRule {
+
+  constructor() : this(lazy(LazyThreadSafetyMode.PUBLICATION) { RandomSource.default() })
+
+  override fun apply(base: Statement, description: Description) =
+    object : Statement() {
+      override fun evaluate() {
+        val result = base.runCatching { evaluate() }
+        result.onFailure {
+          if (rs.isInitialized()) {
+            println(
+              "55negqf33k Test ${description.displayName} failed using " +
+                "RandomSource with seed=${rs.value.seed}"
+            )
+          }
+        }
+        result.getOrThrow()
+      }
+    }
+}