Added tests for "Tap to remove"

app/src/test/java/org/thoughtcrime/securesms/reactions/ReactionsViewModelTest.kt

@@ -0,0 +1,80 @@
+/*
+ * Copyright 2025 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.thoughtcrime.securesms.reactions
+
+import android.app.Application
+import io.mockk.every
+import io.mockk.mockk
+import io.mockk.verify
+import io.reactivex.rxjava3.core.Completable
+import io.reactivex.rxjava3.plugins.RxJavaPlugins
+import io.reactivex.rxjava3.schedulers.TestScheduler
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.annotation.Config
+import org.thoughtcrime.securesms.database.model.MessageId
+import java.util.NoSuchElementException
+
+@RunWith(RobolectricTestRunner::class)
+@Config(manifest = Config.NONE, application = Application::class)
+class ReactionsViewModelTest {
+
+  private val testScheduler = TestScheduler()
+  private val repository = mockk<ReactionsRepository>()
+
+  @Before
+  fun setUp() {
+    RxJavaPlugins.setInitIoSchedulerHandler { testScheduler }
+    RxJavaPlugins.setIoSchedulerHandler { testScheduler }
+  }
+
+  @After
+  fun tearDown() {
+    RxJavaPlugins.reset()
+  }
+
+  @Test
+  fun `Given a message Id, when I removeReactionEmoji, then I expect Success`() {
+    // GIVEN
+    val messageId = MessageId(0)
+    val testSubject = ReactionsViewModel(
+      repository,
+      messageId
+    )
+    every { repository.sendReactionRemoval(any()) } returns Completable.complete()
+
+    // WHEN
+    val result = testSubject.removeReactionEmoji()
+
+    // THEN
+    verify(exactly = 1) { repository.sendReactionRemoval(any()) }
+    result.test().assertNoErrors()
+  }
+
+  @Test
+  fun `Given an invalid message Id, when I removeReactionEmoji, then I expect Failure`() {
+    // GIVEN
+    val messageId = MessageId(0)
+    val testSubject = ReactionsViewModel(
+      repository,
+      messageId
+    )
+    every { repository.sendReactionRemoval(any()) } returns Completable.error(NoSuchElementException())
+
+    // WHEN
+    val result = testSubject.removeReactionEmoji()
+    testScheduler.triggerActions()
+
+    // THEN
+    verify(exactly = 1) { repository.sendReactionRemoval(any()) }
+    result.test().assertError(NoSuchElementException::class.java)
+  }
+
+
+}