Fix Part of #4236 : Add tests for AsyncResultSubject

testing/src/main/java/org/oppia/android/testing/data/AsyncResultSubject.kt

@@ -20,8 +20,6 @@ import com.google.common.truth.extensions.proto.LiteProtoTruth.assertThat
 import com.google.protobuf.MessageLite
 import org.oppia.android.util.data.AsyncResult
 
-// TODO(#4236): Add tests for this class.
-
 /**
  * Truth subject for verifying properties of [AsyncResult]s.
  *

testing/src/test/java/org/oppia/android/testing/data/AsyncResultSubjectTest.kt

@@ -0,0 +1,79 @@
+package org.oppia.android.testing.data
+
+import com.google.common.truth.Truth.assertThat
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.oppia.android.util.data.AsyncResult
+import org.robolectric.RobolectricTestRunner
+
+@RunWith(RobolectricTestRunner::class)
+class AsyncResultSubjectTest {
+
+  @Test
+  fun testAsyncResultPending_isPending() {
+    val pendingResult: AsyncResult<String> = AsyncResult.Pending()
+
+    AsyncResultSubject.assertThat(pendingResult).isPending()
+  }
+
+  @Test
+  fun testAsyncResultPending_isNotSuccess() {
+    val pendingResult: AsyncResult<String> = AsyncResult.Pending()
+
+    AsyncResultSubject.assertThat(pendingResult).isNotSuccess()
+  }
+
+  @Test
+  fun testAsyncResultSuccess_isSuccess() {
+    val successResult: AsyncResult<String> = AsyncResult.Success("Success value")
+
+    AsyncResultSubject.assertThat(successResult).isSuccess()
+  }
+
+  @Test
+  fun testAsyncResultSuccess_hasSuccessValueWhere_matchesExpected() {
+    val successResult: AsyncResult<String> = AsyncResult.Success("Success value")
+
+    AsyncResultSubject.assertThat(successResult).hasSuccessValueWhere {
+      // Here we are verifying that the value is "Success value"
+      assertThat(this).isEqualTo("Success value")
+    }
+  }
+
+  @Test
+  fun testAsyncResultSuccess_isStringSuccessThat() {
+    val successResult: AsyncResult<String> = AsyncResult.Success("Success value")
+
+    AsyncResultSubject.assertThat(successResult).isStringSuccessThat().isEqualTo("Success value")
+  }
+
+  @Test
+  fun testAsyncResultFailure_isFailure() {
+    val failureResult: AsyncResult<String> = AsyncResult.Failure(Throwable("Error"))
+
+    AsyncResultSubject.assertThat(failureResult).isFailure()
+  }
+
+  @Test
+  fun testAsyncResultFailure_isFailureThat_matchesExpectedError() {
+    val failureResult: AsyncResult<String> = AsyncResult.Failure(Throwable("Error"))
+
+    AsyncResultSubject.assertThat(failureResult).isFailureThat().hasMessageThat().contains("Error")
+  }
+
+  @Test
+  fun testAsyncResultSuccess_isNewerOrSameAgeAs() {
+    val successResult1: AsyncResult<String> = AsyncResult.Success("First")
+    val successResult2: AsyncResult<String> = AsyncResult.Success("Second")
+
+    AsyncResultSubject.assertThat(successResult1).isNewerOrSameAgeAs(successResult2)
+  }
+
+  @Test
+  fun testAsyncResultFailure_hasSameEffectiveValueAs_differentError() {
+    val failureResult1: AsyncResult<String> = AsyncResult.Failure(Throwable("Error"))
+    val failureResult2: AsyncResult<String> = AsyncResult.Failure(Throwable("Different Error"))
+
+    AsyncResultSubject.assertThat(failureResult1).hasSameEffectiveValueAs(failureResult2).isFalse()
+  }
+}

testing/src/test/java/org/oppia/android/testing/data/BUILD.bazel

@@ -33,3 +33,21 @@ oppia_android_test(
         "//utility/src/main/java/org/oppia/android/util/networking:debug_module",
     ],
 )
+
+# Adding test for AsyncResultSubject
+oppia_android_test(
+    name = "AsyncResultSubjectTest",
+    srcs = ["AsyncResultSubjectTest.kt"],
+    custom_package = "org.oppia.android.testing.data",
+    test_class = "org.oppia.android.testing.data.AsyncResultSubjectTest",
+    test_manifest = "//testing:test_manifest",
+    deps = [
+        "//testing/src/main/java/org/oppia/android/testing/data:async_result_subject",
+        "//testing/src/main/java/org/oppia/android/testing/robolectric:test_module",
+        "//third_party:androidx_test_ext_junit",
+        "//third_party:com_google_truth_truth",
+        "//third_party:junit_junit",
+        "//third_party:org_robolectric_robolectric",
+        "//third_party:robolectric_android-all",
+    ],
+)