diff --git a/mirai-core/src/commonTest/kotlin/test/events.kt b/mirai-core/src/commonTest/kotlin/test/events.kt
new file mode 100644
index 000000000..dd063d420
--- /dev/null
+++ b/mirai-core/src/commonTest/kotlin/test/events.kt
@@ -0,0 +1,57 @@
+/*
+ * Copyright 2019-2021 Mamoe Technologies and contributors.
+ *
+ *  此源代码的使用受 GNU AFFERO GENERAL PUBLIC LICENSE version 3 许可证的约束, 可以在以下链接找到该许可证.
+ *  Use of this source code is governed by the GNU AGPLv3 license that can be found through the following link.
+ *
+ *  https://github.com/mamoe/mirai/blob/master/LICENSE
+ */
+
+package net.mamoe.mirai.internal.test
+
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import net.mamoe.mirai.event.Event
+import net.mamoe.mirai.event.GlobalEventChannel
+import java.util.concurrent.atomic.AtomicInteger
+import kotlin.test.assertEquals
+
+@OptIn(ExperimentalCoroutinesApi::class)
+internal inline fun <reified T : Event, R> assertEventBroadcasts(times: Int = 1, block: () -> R): R {
+    val receivedEvents = AtomicInteger(0)
+    val listener = GlobalEventChannel.subscribeAlways<T> {
+        receivedEvents.incrementAndGet()
+    }
+    try {
+        return block()
+    } finally {
+        listener.complete()
+        assertEquals(
+            times,
+            receivedEvents.get(),
+            "Expected event ${T::class.simpleName} broadcast $times time(s). But actual is ${receivedEvents.get()}."
+        )
+    }
+}
+
+@OptIn(ExperimentalCoroutinesApi::class)
+internal inline fun <reified T : Event> assertEventBroadcasts(times: Int = 1, block: () -> Unit) {
+    val receivedEvents = AtomicInteger(0)
+    val listener = GlobalEventChannel.subscribeAlways<T> {
+        receivedEvents.incrementAndGet()
+    }
+    try {
+        return block()
+    } finally {
+        listener.complete()
+        assertEquals(
+            times,
+            receivedEvents.get(),
+            "Expected event ${T::class.simpleName} broadcast $times time(s). But actual is ${receivedEvents.get()}."
+        )
+    }
+}
+
+@OptIn(ExperimentalCoroutinesApi::class)
+internal inline fun <reified T : Event, R> assertEventNotBroadcast(block: () -> R): R {
+    return assertEventBroadcasts<T, R>(0, block)
+}
\ No newline at end of file
diff --git a/mirai-core/src/commonTest/kotlin/test/utils.kt b/mirai-core/src/commonTest/kotlin/test/utils.kt
index ef765f5b1..2c4e1ab20 100644
--- a/mirai-core/src/commonTest/kotlin/test/utils.kt
+++ b/mirai-core/src/commonTest/kotlin/test/utils.kt
@@ -16,12 +16,17 @@ import kotlinx.coroutines.withTimeout
 import kotlin.coroutines.CoroutineContext
 import kotlin.coroutines.EmptyCoroutineContext
 import kotlin.time.Duration
+import kotlin.time.seconds
 
 fun runBlockingUnit(
     context: CoroutineContext = EmptyCoroutineContext,
     block: suspend CoroutineScope.() -> Unit
 ) {
-    return runBlocking(context, block)
+    return runBlocking(context) {
+        withTimeout(60.seconds) { // always checks for infinite runs.
+            block()
+        }
+    }
 }
 
 fun runBlockingUnit(