Refactor coroutine testing setup (#1583)

* coroutine-utils: init

* coroutine-utils-testing: init

* format-common: switch over to using DispatcherProvider

* Convert Binds method to an extension function

* Add Dispatcher module

14 files changed, 173 insertions, 13 deletions

diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index 855f1189..d0a0dab4 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -74,6 +74,7 @@ dependencies {
   implementation(libs.androidx.annotation)
   coreLibraryDesugaring(libs.android.desugarJdkLibs)
   implementation(projects.autofillParser)
+  implementation(projects.coroutineUtils)
   implementation(projects.cryptoPgpainless)
   implementation(projects.formatCommon)
   implementation(projects.openpgpKtx)
diff --git a/app/src/main/java/dev/msfjarvis/aps/injection/coroutines/DispatcherModule.kt b/app/src/main/java/dev/msfjarvis/aps/injection/coroutines/DispatcherModule.kt
new file mode 100644
index 00000000..bf84fc27
--- /dev/null
+++ b/app/src/main/java/dev/msfjarvis/aps/injection/coroutines/DispatcherModule.kt
@@ -0,0 +1,19 @@
+/*
+ * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package dev.msfjarvis.aps.injection.coroutines
+
+import dagger.Binds
+import dagger.Module
+import dagger.hilt.InstallIn
+import dagger.hilt.components.SingletonComponent
+import dev.msfjarvis.aps.util.coroutines.DefaultDispatcherProvider
+import dev.msfjarvis.aps.util.coroutines.DispatcherProvider
+
+@Module
+@InstallIn(SingletonComponent::class)
+interface DispatcherModule {
+  @Binds fun DefaultDispatcherProvider.bind(): DispatcherProvider
+}
diff --git a/app/src/main/java/dev/msfjarvis/aps/injection/totp/TotpModule.kt b/app/src/main/java/dev/msfjarvis/aps/injection/totp/TotpModule.kt
index e02a3b86..859559cd 100644
--- a/app/src/main/java/dev/msfjarvis/aps/injection/totp/TotpModule.kt
+++ b/app/src/main/java/dev/msfjarvis/aps/injection/totp/TotpModule.kt
@@ -15,5 +15,5 @@ import dev.msfjarvis.aps.util.totp.UriTotpFinder
 @Module
 @InstallIn(ActivityComponent::class)
 interface TotpModule {
-  @Binds abstract fun bindTotpFinder(totpFinder: UriTotpFinder): TotpFinder
+  @Binds fun UriTotpFinder.bind(): TotpFinder
 }
diff --git a/coroutine-utils-testing/api/coroutine-utils-testing.api b/coroutine-utils-testing/api/coroutine-utils-testing.api
new file mode 100644
index 00000000..a90e209f
--- /dev/null
+++ b/coroutine-utils-testing/api/coroutine-utils-testing.api
@@ -0,0 +1,8 @@
+public final class dev/msfjarvis/aps/test/CoroutineTestRule : org/junit/rules/TestWatcher {
+	public fun <init> ()V
+	public fun <init> (Lkotlinx/coroutines/test/TestDispatcher;)V
+	public synthetic fun <init> (Lkotlinx/coroutines/test/TestDispatcher;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public final fun getTestDispatcher ()Lkotlinx/coroutines/test/TestDispatcher;
+	public final fun getTestDispatcherProvider ()Ldev/msfjarvis/aps/util/coroutines/DispatcherProvider;
+}
+
diff --git a/coroutine-utils-testing/build.gradle.kts b/coroutine-utils-testing/build.gradle.kts
new file mode 100644
index 00000000..96d87dc1
--- /dev/null
+++ b/coroutine-utils-testing/build.gradle.kts
@@ -0,0 +1,14 @@
+/*
+ * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+plugins {
+  kotlin("jvm")
+  id("com.github.android-password-store.kotlin-library")
+}
+
+dependencies {
+  implementation(projects.coroutineUtils)
+  implementation(libs.testing.junit)
+  implementation(libs.kotlin.coroutines.test)
+}
diff --git a/coroutine-utils-testing/src/main/kotlin/dev/msfjarvis/aps/test/CoroutineTestRule.kt b/coroutine-utils-testing/src/main/kotlin/dev/msfjarvis/aps/test/CoroutineTestRule.kt
new file mode 100644
index 00000000..fa4a2d41
--- /dev/null
+++ b/coroutine-utils-testing/src/main/kotlin/dev/msfjarvis/aps/test/CoroutineTestRule.kt
@@ -0,0 +1,45 @@
+/*
+ * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package dev.msfjarvis.aps.test
+
+import dev.msfjarvis.aps.util.coroutines.DispatcherProvider
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.TestCoroutineScheduler
+import kotlinx.coroutines.test.TestDispatcher
+import kotlinx.coroutines.test.UnconfinedTestDispatcher
+import kotlinx.coroutines.test.resetMain
+import kotlinx.coroutines.test.setMain
+import org.junit.rules.TestWatcher
+import org.junit.runner.Description
+
+/**
+ * JUnit [TestWatcher] to correctly handle setting and resetting a given [testDispatcher] for tests.
+ */
+@ExperimentalCoroutinesApi
+public class CoroutineTestRule(
+  public val testDispatcher: TestDispatcher = UnconfinedTestDispatcher(TestCoroutineScheduler()),
+) : TestWatcher() {
+
+  public val testDispatcherProvider: DispatcherProvider =
+    object : DispatcherProvider {
+      override fun default(): CoroutineDispatcher = testDispatcher
+      override fun io(): CoroutineDispatcher = testDispatcher
+      override fun main(): CoroutineDispatcher = testDispatcher
+      override fun unconfined(): CoroutineDispatcher = testDispatcher
+    }
+
+  override fun starting(description: Description?) {
+    super.starting(description)
+    Dispatchers.setMain(testDispatcher)
+  }
+
+  override fun finished(description: Description?) {
+    super.finished(description)
+    Dispatchers.resetMain()
+  }
+}
diff --git a/coroutine-utils/api/coroutine-utils.api b/coroutine-utils/api/coroutine-utils.api
new file mode 100644
index 00000000..000dde65
--- /dev/null
+++ b/coroutine-utils/api/coroutine-utils.api
@@ -0,0 +1,22 @@
+public final class dev/msfjarvis/aps/util/coroutines/DefaultDispatcherProvider : dev/msfjarvis/aps/util/coroutines/DispatcherProvider {
+	public fun <init> ()V
+	public fun default ()Lkotlinx/coroutines/CoroutineDispatcher;
+	public fun io ()Lkotlinx/coroutines/CoroutineDispatcher;
+	public fun main ()Lkotlinx/coroutines/CoroutineDispatcher;
+	public fun unconfined ()Lkotlinx/coroutines/CoroutineDispatcher;
+}
+
+public abstract interface class dev/msfjarvis/aps/util/coroutines/DispatcherProvider {
+	public abstract fun default ()Lkotlinx/coroutines/CoroutineDispatcher;
+	public abstract fun io ()Lkotlinx/coroutines/CoroutineDispatcher;
+	public abstract fun main ()Lkotlinx/coroutines/CoroutineDispatcher;
+	public abstract fun unconfined ()Lkotlinx/coroutines/CoroutineDispatcher;
+}
+
+public final class dev/msfjarvis/aps/util/coroutines/DispatcherProvider$DefaultImpls {
+	public static fun default (Ldev/msfjarvis/aps/util/coroutines/DispatcherProvider;)Lkotlinx/coroutines/CoroutineDispatcher;
+	public static fun io (Ldev/msfjarvis/aps/util/coroutines/DispatcherProvider;)Lkotlinx/coroutines/CoroutineDispatcher;
+	public static fun main (Ldev/msfjarvis/aps/util/coroutines/DispatcherProvider;)Lkotlinx/coroutines/CoroutineDispatcher;
+	public static fun unconfined (Ldev/msfjarvis/aps/util/coroutines/DispatcherProvider;)Lkotlinx/coroutines/CoroutineDispatcher;
+}
+
diff --git a/coroutine-utils/build.gradle.kts b/coroutine-utils/build.gradle.kts
new file mode 100644
index 00000000..2a20df08
--- /dev/null
+++ b/coroutine-utils/build.gradle.kts
@@ -0,0 +1,13 @@
+/*
+ * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+plugins {
+  kotlin("jvm")
+  id("com.github.android-password-store.kotlin-library")
+}
+
+dependencies {
+  implementation(libs.kotlin.coroutines.core)
+  implementation(libs.dagger.hilt.core)
+}
diff --git a/coroutine-utils/src/main/kotlin/dev/msfjarvis/aps/util/coroutines/DispatcherProvider.kt b/coroutine-utils/src/main/kotlin/dev/msfjarvis/aps/util/coroutines/DispatcherProvider.kt
new file mode 100644
index 00000000..a7c4530d
--- /dev/null
+++ b/coroutine-utils/src/main/kotlin/dev/msfjarvis/aps/util/coroutines/DispatcherProvider.kt
@@ -0,0 +1,22 @@
+/*
+ * Copyright © 2014-2021 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package dev.msfjarvis.aps.util.coroutines
+
+import javax.inject.Inject
+import kotlinx.coroutines.CoroutineDispatcher
+import kotlinx.coroutines.Dispatchers
+
+/** Interface to allow abstracting individual [CoroutineDispatcher]s out of class dependencies. */
+public interface DispatcherProvider {
+
+  public fun main(): CoroutineDispatcher = Dispatchers.Main
+  public fun default(): CoroutineDispatcher = Dispatchers.Default
+  public fun io(): CoroutineDispatcher = Dispatchers.IO
+  public fun unconfined(): CoroutineDispatcher = Dispatchers.Unconfined
+}
+
+/** Concrete type for [DispatcherProvider] with all the defaults from the class. */
+public class DefaultDispatcherProvider @Inject constructor() : DispatcherProvider
diff --git a/format-common/api/format-common.api b/format-common/api/format-common.api
index d0caaf78..629644e3 100644
--- a/format-common/api/format-common.api
+++ b/format-common/api/format-common.api
@@ -1,5 +1,5 @@
 public final class dev/msfjarvis/aps/data/passfile/PasswordEntry {
-	public fun <init> (Ldev/msfjarvis/aps/util/time/UserClock;Ldev/msfjarvis/aps/util/totp/TotpFinder;Lkotlinx/coroutines/CoroutineScope;[B)V
+	public fun <init> (Ldev/msfjarvis/aps/util/time/UserClock;Ldev/msfjarvis/aps/util/totp/TotpFinder;Ldev/msfjarvis/aps/util/coroutines/DispatcherProvider;Lkotlinx/coroutines/CoroutineScope;[B)V
 	public final fun getExtraContent ()Ljava/util/Map;
 	public final fun getExtraContentString ()Ljava/lang/String;
 	public final fun getExtraContentWithoutAuthData ()Ljava/lang/String;
diff --git a/format-common/build.gradle.kts b/format-common/build.gradle.kts
index e5400bcc..3b940573 100644
--- a/format-common/build.gradle.kts
+++ b/format-common/build.gradle.kts
@@ -9,11 +9,13 @@ plugins {
 }
 
 dependencies {
+  implementation(projects.coroutineUtils)
   implementation(libs.androidx.annotation)
   implementation(libs.dagger.hilt.core)
   implementation(libs.thirdparty.commons.codec)
   implementation(libs.thirdparty.kotlinResult)
   implementation(libs.kotlin.coroutines.core)
+  testImplementation(projects.coroutineUtilsTesting)
   testImplementation(libs.bundles.testDependencies)
   testImplementation(libs.kotlin.coroutines.test)
 }
diff --git a/format-common/src/main/kotlin/dev/msfjarvis/aps/data/passfile/PasswordEntry.kt b/format-common/src/main/kotlin/dev/msfjarvis/aps/data/passfile/PasswordEntry.kt
index 408069a2..81398b45 100644
--- a/format-common/src/main/kotlin/dev/msfjarvis/aps/data/passfile/PasswordEntry.kt
+++ b/format-common/src/main/kotlin/dev/msfjarvis/aps/data/passfile/PasswordEntry.kt
@@ -9,6 +9,7 @@ import com.github.michaelbull.result.mapBoth
 import dagger.assisted.Assisted
 import dagger.assisted.AssistedFactory
 import dagger.assisted.AssistedInject
+import dev.msfjarvis.aps.util.coroutines.DispatcherProvider
 import dev.msfjarvis.aps.util.time.UserClock
 import dev.msfjarvis.aps.util.totp.Otp
 import dev.msfjarvis.aps.util.totp.TotpFinder
@@ -32,6 +33,8 @@ constructor(
   clock: UserClock,
   /** [TotpFinder] implementation to extract data from a TOTP URI */
   totpFinder: TotpFinder,
+  /** Instance of [DispatcherProvider] to select an IO dispatcher for emitting TOTP values. */
+  dispatcherProvider: DispatcherProvider,
   /**
    * A cancellable [CoroutineScope] inside which we constantly emit new TOTP values as time elapses
    */
@@ -81,7 +84,7 @@ constructor(
     username = findUsername()
     totpSecret = totpFinder.findSecret(content)
     if (totpSecret != null) {
-      scope.launch {
+      scope.launch(dispatcherProvider.io()) {
         val digits = totpFinder.findDigits(content)
         val totpPeriod = totpFinder.findPeriod(content)
         val totpAlgorithm = totpFinder.findAlgorithm(content)
diff --git a/format-common/src/test/kotlin/dev/msfjarvis/aps/data/passfile/PasswordEntryTest.kt b/format-common/src/test/kotlin/dev/msfjarvis/aps/data/passfile/PasswordEntryTest.kt
index 2923946e..32066cc3 100644
--- a/format-common/src/test/kotlin/dev/msfjarvis/aps/data/passfile/PasswordEntryTest.kt
+++ b/format-common/src/test/kotlin/dev/msfjarvis/aps/data/passfile/PasswordEntryTest.kt
@@ -5,6 +5,7 @@
 
 package dev.msfjarvis.aps.data.passfile
 
+import dev.msfjarvis.aps.test.CoroutineTestRule
 import dev.msfjarvis.aps.util.time.TestUserClock
 import dev.msfjarvis.aps.util.totp.TotpFinder
 import java.util.Locale
@@ -16,15 +17,22 @@ import kotlin.test.assertNull
 import kotlin.test.assertTrue
 import kotlin.time.ExperimentalTime
 import kotlinx.coroutines.ExperimentalCoroutinesApi
-import kotlinx.coroutines.test.StandardTestDispatcher
 import kotlinx.coroutines.test.TestScope
 import kotlinx.coroutines.test.runTest
+import org.junit.Rule
 
 @OptIn(ExperimentalCoroutinesApi::class, ExperimentalTime::class)
 class PasswordEntryTest {
 
+  @get:Rule val coroutineTestRule: CoroutineTestRule = CoroutineTestRule()
   private fun makeEntry(content: String) =
-    PasswordEntry(fakeClock, testFinder, scope, content.encodeToByteArray())
+    PasswordEntry(
+      fakeClock,
+      testFinder,
+      coroutineTestRule.testDispatcherProvider,
+      TestScope(coroutineTestRule.testDispatcher),
+      content.encodeToByteArray(),
+    )
 
   @Test
   fun testGetPassword() {
@@ -125,19 +133,20 @@ class PasswordEntryTest {
 
   @Test
   @Ignore("Timing with runTest seems hard to implement right now")
-  fun testGeneratesOtpFromTotpUri() =
-    scope.runTest {
+  fun testGeneratesOtpFromTotpUri() {
+    runTest {
       val entry = makeEntry("secret\nextra\n$TOTP_URI")
       assertTrue(entry.hasTotp())
       val code = entry.totp.value
       assertNotNull(code) { "Generated OTP cannot be null" }
       assertEquals("818800", code)
     }
+  }
 
   @Test
   @Ignore("Timing with runTest seems hard to implement right now")
-  fun testGeneratesOtpWithOnlyUriInFile() =
-    scope.runTest {
+  fun testGeneratesOtpWithOnlyUriInFile() {
+    runTest {
       val entry = makeEntry(TOTP_URI)
       assertNull(entry.password)
       assertTrue(entry.hasTotp())
@@ -145,6 +154,7 @@ class PasswordEntryTest {
       assertNotNull(code) { "Generated OTP cannot be null" }
       assertEquals("818800", code)
     }
+  }
 
   @Test
   fun testOnlyLooksForUriInFirstLine() {
@@ -171,9 +181,6 @@ class PasswordEntryTest {
     const val TOTP_URI =
       "otpauth://totp/ACME%20Co:john@example.com?secret=HXDMVJECJJWSRB3HWIZR4IFUGFTMXBOZ&issuer=ACME%20Co&algorithm=SHA1&digits=6&period=30"
 
-    val dispatcher = StandardTestDispatcher()
-    val scope = TestScope(dispatcher)
-
     val fakeClock = TestUserClock()
 
     // This implementation is hardcoded for the URI above.
diff --git a/settings.gradle.kts b/settings.gradle.kts
index 6c600dc7..9ea2cd3b 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -42,6 +42,10 @@ include("app")
 
 include("autofill-parser")
 
+include("coroutine-utils")
+
+include("coroutine-utils-testing")
+
 include("crypto-common")
 
 include("crypto-pgpainless")
@@ -50,4 +54,4 @@ include("format-common")
 
 include("openpgp-ktx")
 
-include(":dependency-sync")
+include("dependency-sync")