add two test

app/src/test/java/com/example/hpostesting/util/TestCoroutineRule.kt

@@ -0,0 +1,28 @@
+package com.example.hpostesting.util
+
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.TestCoroutineDispatcher
+import kotlinx.coroutines.test.TestCoroutineScope
+import kotlinx.coroutines.test.resetMain
+import kotlinx.coroutines.test.setMain
+import org.junit.rules.TestWatcher
+import org.junit.runner.Description
+
+@ExperimentalCoroutinesApi
+class TestCoroutineRule : TestWatcher(), TestCoroutineScope by TestCoroutineScope() {
+
+    private val testCoroutineDispatcher = TestCoroutineDispatcher()
+
+    override fun starting(description: Description?) {
+        super.starting(description)
+        Dispatchers.setMain(testCoroutineDispatcher)
+    }
+
+    override fun finished(description: Description?) {
+        super.finished(description)
+        Dispatchers.resetMain()
+        cleanupTestCoroutines()
+    }
+}