From 928d6581c93181eddcffea9291362eb520ae4f31 Mon Sep 17 00:00:00 2001
From: Grigory Kruglov <grigory@kruglov.ca>
Date: Mon, 14 Feb 2022 19:09:08 -0800
Subject: [PATCH] Get browser-domains tests to pass

---
 components/browser/domains/build.gradle       |  1 +
 .../browser/domains/autocomplete/Providers.kt | 16 ++++++----------
 .../BaseDomainAutocompleteProviderTest.kt     | 19 +++++++++++++------
 3 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/components/browser/domains/build.gradle b/components/browser/domains/build.gradle
index 438782bca9f..65bb01bf105 100644
--- a/components/browser/domains/build.gradle
+++ b/components/browser/domains/build.gradle
@@ -31,6 +31,7 @@ dependencies {
 
     testImplementation Dependencies.androidx_test_junit
     testImplementation Dependencies.testing_robolectric
+    testImplementation Dependencies.testing_coroutines
 }
 
 apply from: '../../../publish.gradle'
diff --git a/components/browser/domains/src/main/java/mozilla/components/browser/domains/autocomplete/Providers.kt b/components/browser/domains/src/main/java/mozilla/components/browser/domains/autocomplete/Providers.kt
index c1106d22152..1250e05e2d8 100644
--- a/components/browser/domains/src/main/java/mozilla/components/browser/domains/autocomplete/Providers.kt
+++ b/components/browser/domains/src/main/java/mozilla/components/browser/domains/autocomplete/Providers.kt
@@ -5,10 +5,7 @@
 package mozilla.components.browser.domains.autocomplete
 
 import android.content.Context
-import kotlinx.coroutines.CoroutineScope
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.async
-import kotlinx.coroutines.launch
+import kotlinx.coroutines.*
 import mozilla.components.browser.domains.CustomDomains
 import mozilla.components.browser.domains.Domain
 import mozilla.components.browser.domains.Domains
@@ -47,17 +44,16 @@ private fun CustomDomains.asLoader(): DomainsLoader = { context: Context -> load
  */
 open class BaseDomainAutocompleteProvider(
     private val list: DomainList,
-    private val domainsLoader: DomainsLoader
-) : DomainAutocompleteProvider, CoroutineScope by CoroutineScope(Dispatchers.IO) {
+    private val domainsLoader: DomainsLoader,
+    private val scope: CoroutineScope = CoroutineScope(Dispatchers.IO)
+) : DomainAutocompleteProvider {
 
     // We compute 'domains' on the worker thread; make sure it's immediately visible on the UI thread.
     @Volatile
     var domains: List<Domain> = emptyList()
 
-    fun initialize(context: Context) {
-        launch {
-            domains = async { domainsLoader(context) }.await()
-        }
+    suspend fun initialize(context: Context) = withContext(scope.coroutineContext) {
+        domains = domainsLoader(context)
     }
 
     /**
diff --git a/components/browser/domains/src/test/java/mozilla/components/browser/domains/BaseDomainAutocompleteProviderTest.kt b/components/browser/domains/src/test/java/mozilla/components/browser/domains/BaseDomainAutocompleteProviderTest.kt
index 0e2d6420712..105f6928dea 100644
--- a/components/browser/domains/src/test/java/mozilla/components/browser/domains/BaseDomainAutocompleteProviderTest.kt
+++ b/components/browser/domains/src/test/java/mozilla/components/browser/domains/BaseDomainAutocompleteProviderTest.kt
@@ -6,7 +6,10 @@ package mozilla.components.browser.domains
 
 import android.content.Context
 import androidx.test.ext.junit.runners.AndroidJUnit4
-import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.StandardTestDispatcher
+import kotlinx.coroutines.test.TestScope
+import kotlinx.coroutines.test.runTest
 import mozilla.components.browser.domains.autocomplete.BaseDomainAutocompleteProvider
 import mozilla.components.browser.domains.autocomplete.DomainAutocompleteProvider
 import mozilla.components.browser.domains.autocomplete.DomainList
@@ -18,8 +21,11 @@ import org.junit.Assert.assertTrue
 import org.junit.Test
 import org.junit.runner.RunWith
 
+@ExperimentalCoroutinesApi
 @RunWith(AndroidJUnit4::class)
 class BaseDomainAutocompleteProviderTest {
+    private val dispatcher = StandardTestDispatcher()
+    private val scope = TestScope(dispatcher)
 
     @Test
     fun `empty provider with DEFAULT list returns nothing`() {
@@ -98,6 +104,12 @@ class BaseDomainAutocompleteProviderTest {
         assertNoCompletion(provider, "wwww")
         assertNoCompletion(provider, "yahoo")
     }
+
+    private fun createAndInitProvider(context: Context, list: DomainList, loader: DomainsLoader): DomainAutocompleteProvider {
+        return BaseDomainAutocompleteProvider(list, loader, scope).apply {
+            runTest(dispatcher) { initialize(context) }
+        }
+    }
 }
 
 private fun assertCompletion(
@@ -125,8 +137,3 @@ private fun assertNoCompletion(provider: DomainAutocompleteProvider, input: Stri
 
     assertNull("Result should be null", result)
 }
-
-private fun createAndInitProvider(context: Context, list: DomainList, loader: DomainsLoader): DomainAutocompleteProvider =
-    object : BaseDomainAutocompleteProvider(list, loader) {
-        override val coroutineContext = super.coroutineContext + Dispatchers.Main
-    }.apply { initialize(context) }