Introduced helpers for tests

app/src/test/java/com/sadellie/unitto/CoroutinesTestUtils.kt

@@ -0,0 +1,61 @@
+/*
+ * Unitto is a unit converter for Android
+ * Copyright (c) 2022 Elshan Agaev
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sadellie.unitto
+
+import android.os.StrictMode
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.TestDispatcher
+import kotlinx.coroutines.test.TestResult
+import kotlinx.coroutines.test.TestScope
+import kotlinx.coroutines.test.UnconfinedTestDispatcher
+import kotlinx.coroutines.test.resetMain
+import kotlinx.coroutines.test.runTest
+import kotlinx.coroutines.test.setMain
+import org.junit.Test
+import org.junit.rules.TestWatcher
+import org.junit.runner.Description
+
+@ExperimentalCoroutinesApi
+class CoroutineTestRule(private val dispatcher: TestDispatcher = UnconfinedTestDispatcher()) :
+    TestWatcher() {
+
+    override fun starting(description: Description) {
+        super.starting(description)
+        Dispatchers.setMain(dispatcher)
+    }
+
+    override fun finished(description: Description) {
+        super.finished(description)
+        Dispatchers.resetMain()
+    }
+
+}
+
+@OptIn(ExperimentalCoroutinesApi::class)
+@Test
+fun testInViewModel(testBody: suspend TestScope.(CoroutineScope) -> Unit): TestResult = runTest {
+    // https://github.com/robolectric/robolectric/issues/6377#issuecomment-843779001
+    StrictMode.enableDefaults()
+    val testDispatcher = UnconfinedTestDispatcher(testScheduler)
+    Dispatchers.setMain(testDispatcher)
+    testBody(CoroutineScope(testDispatcher))
+    Dispatchers.resetMain()
+}

app/src/test/java/com/sadellie/unitto/screens/MainViewModelTest.kt

@@ -18,8 +18,8 @@
 
 package com.sadellie.unitto.screens
 
-import android.os.StrictMode
 import androidx.room.Room
+import com.sadellie.unitto.CoroutineTestRule
 import com.sadellie.unitto.data.KEY_0
 import com.sadellie.unitto.data.KEY_1
 import com.sadellie.unitto.data.KEY_2
@@ -46,44 +46,21 @@ import com.sadellie.unitto.data.units.AllUnitsRepository
 import com.sadellie.unitto.data.units.database.MyBasedUnitDatabase
 import com.sadellie.unitto.data.units.database.MyBasedUnitsRepository
 import com.sadellie.unitto.screens.main.MainViewModel
-import kotlinx.coroutines.CoroutineScope
+import com.sadellie.unitto.testInViewModel
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.flow.launchIn
-import kotlinx.coroutines.test.TestDispatcher
-import kotlinx.coroutines.test.UnconfinedTestDispatcher
 import kotlinx.coroutines.test.resetMain
-import kotlinx.coroutines.test.runTest
-import kotlinx.coroutines.test.setMain
 import org.junit.Assert.assertEquals
 import org.junit.Before
 import org.junit.Rule
 import org.junit.Test
-import org.junit.rules.TestWatcher
-import org.junit.runner.Description
 import org.junit.runner.RunWith
 import org.robolectric.RobolectricTestRunner
 import org.robolectric.RuntimeEnvironment
 import org.robolectric.annotation.Config
 
 
-@ExperimentalCoroutinesApi
-class CoroutineTestRule(private val dispatcher: TestDispatcher = UnconfinedTestDispatcher()) :
-    TestWatcher() {
-
-    override fun starting(description: Description) {
-        super.starting(description)
-        Dispatchers.setMain(dispatcher)
-    }
-
-    override fun finished(description: Description) {
-        super.finished(description)
-        Dispatchers.resetMain()
-    }
-
-}
-
-
 @OptIn(ExperimentalCoroutinesApi::class)
 @Config(manifest = Config.NONE)
 @RunWith(RobolectricTestRunner::class)
@@ -112,12 +89,8 @@ class MainViewModelTest {
     }
 
     @Test
-    fun processInputTest() = runTest {
+    fun processInputTest() = testInViewModel { coroutineScope ->
-        // https://github.com/robolectric/robolectric/issues/6377#issuecomment-843779001
+        viewModel.mainFlow.launchIn(coroutineScope)
-        StrictMode.enableDefaults()
-        val testDispatcher = UnconfinedTestDispatcher(testScheduler)
-        Dispatchers.setMain(testDispatcher)
-        viewModel.mainFlow.launchIn(CoroutineScope(testDispatcher))
 
         /**
          * For simplicity comments will have structure:
@@ -360,12 +333,8 @@ class MainViewModelTest {
     }
 
     @Test
-    fun deleteSymbolTest() = runTest {
+    fun deleteSymbolTest() = testInViewModel { coroutineScope ->
-        // https://github.com/robolectric/robolectric/issues/6377#issuecomment-843779001
+        viewModel.mainFlow.launchIn(coroutineScope)
-        StrictMode.enableDefaults()
-        val testDispatcher = UnconfinedTestDispatcher(testScheduler)
-        Dispatchers.setMain(testDispatcher)
-        viewModel.mainFlow.launchIn(CoroutineScope(testDispatcher))
 
         listOf(
             KEY_1, KEY_2, KEY_3, KEY_4, KEY_5, KEY_6, KEY_7, KEY_8, KEY_9, KEY_0,
@@ -391,4 +360,4 @@ class MainViewModelTest {
         Dispatchers.resetMain()
     }
 
-}
+}