Tentatively fix tests regarding initialization of multiple Mirai Console instances

backend/mirai-console/src/MiraiConsoleImplementation.kt

@@ -246,8 +246,9 @@ public interface MiraiConsoleImplementation : CoroutineScope {
             override val resolvedPlugins: MutableList<Plugin> get() = PluginManagerImpl.resolvedPlugins
         }
 
-        internal lateinit var instance: MiraiConsoleImplementation
-        internal val instanceInitialized: Boolean get() = ::instance.isInitialized
+        @Volatile
+        internal var instance: MiraiConsoleImplementation? = null
+        internal val instanceInitialized: Boolean get() = instance != null
         private val initLock = ReentrantLock()
 
         /**
@@ -257,14 +258,15 @@ public interface MiraiConsoleImplementation : CoroutineScope {
          */
         @JvmStatic
         @ConsoleFrontEndImplementation
-        public fun getInstance(): MiraiConsoleImplementation = instance
+        public fun getInstance(): MiraiConsoleImplementation = instance ?: throw UninitializedPropertyAccessException()
 
         /** 由前端调用, 初始化 [MiraiConsole] 实例并启动 */
         @JvmStatic
         @ConsoleFrontEndImplementation
         @Throws(MalformedMiraiConsoleImplementationError::class)
         public fun MiraiConsoleImplementation.start(): Unit = initLock.withLock {
-            if (::instance.isInitialized && instance.isActive) {
+            val instance = instance
+            if (instance != null && instance.isActive) {
                 error(
                     "Mirai Console is already initialized and is currently running. " +
                             "Run MiraiConsole.cancel to kill old instance before starting another instance."

backend/mirai-console/src/internal/MiraiConsoleImplementationBridge.kt

@@ -70,7 +70,7 @@ internal object MiraiConsoleImplementationBridge : CoroutineScope, MiraiConsoleI
     MiraiConsole {
     override val pluginCenter: PluginCenter get() = throw UnsupportedOperationException("PluginCenter is not supported yet")
 
-    private val instance: MiraiConsoleImplementation by MiraiConsoleImplementation.Companion::instance
+    private val instance: MiraiConsoleImplementation get() = MiraiConsoleImplementation.getInstance()
     override val buildDate: Instant by MiraiConsoleBuildConstants::buildDate
     override val version: SemVersion by MiraiConsoleBuildConstants::version
     override val rootPath: Path by instance::rootPath

backend/mirai-console/test/command/TestCommand.kt

@@ -11,9 +11,7 @@
 
 package net.mamoe.mirai.console.command
 
-import kotlinx.coroutines.cancel
 import kotlinx.coroutines.runBlocking
-import net.mamoe.mirai.console.MiraiConsole
 import net.mamoe.mirai.console.Testing
 import net.mamoe.mirai.console.Testing.withTesting
 import net.mamoe.mirai.console.command.CommandManager.INSTANCE.getRegisteredCommands
@@ -24,12 +22,10 @@ import net.mamoe.mirai.console.command.CommandManager.INSTANCE.unregisterCommand
 import net.mamoe.mirai.console.command.descriptor.CommandValueArgumentParser
 import net.mamoe.mirai.console.command.descriptor.ExperimentalCommandDescriptors
 import net.mamoe.mirai.console.command.descriptor.buildCommandArgumentContext
-import net.mamoe.mirai.console.initTestEnvironment
+import net.mamoe.mirai.console.framework.AbstractConsoleTest
 import net.mamoe.mirai.console.internal.command.CommandManagerImpl
 import net.mamoe.mirai.console.internal.command.flattenCommandComponents
 import net.mamoe.mirai.message.data.*
-import org.junit.jupiter.api.AfterAll
-import org.junit.jupiter.api.BeforeAll
 import org.junit.jupiter.api.Test
 import kotlin.test.*
 
@@ -102,21 +98,7 @@ internal val owner by lazy { TestUnitCommandOwner }
 
 
 @OptIn(ExperimentalCommandDescriptors::class)
-internal class TestCommand {
-    companion object {
-        @JvmStatic
-        @BeforeAll
-        fun init() {
-            initTestEnvironment()
-        }
-
-        @AfterAll
-        @JvmStatic
-        fun destroy() {
-            MiraiConsole.cancel()
-        }
-    }
-
+internal class TestCommand : AbstractConsoleTest() {
     @Test
     fun testRegister() {
         try {
@@ -352,8 +334,26 @@ internal class TestCommand {
             println(composite.overloads.joinToString())
 
             composite.withRegistration {
-                assertEquals(1, withTesting { assertSuccess(composite.execute(sender, "mute 123")) }) // one arg, resolves to mute(Int)
-                assertEquals(2, withTesting { assertSuccess(composite.execute(sender, "mute 123 1")) }) // two arg, resolved to mute(Int, Int)
+                assertEquals(
+                    1,
+                    withTesting {
+                        assertSuccess(
+                            composite.execute(
+                                sender,
+                                "mute 123"
+                            )
+                        )
+                    }) // one arg, resolves to mute(Int)
+                assertEquals(
+                    2,
+                    withTesting {
+                        assertSuccess(
+                            composite.execute(
+                                sender,
+                                "mute 123 1"
+                            )
+                        )
+                    }) // two arg, resolved to mute(Int, Int)
             }
         }
     }

backend/mirai-console/test/framework/AbstractConsoleTest.kt

@@ -37,6 +37,8 @@ abstract class AbstractConsoleTest {
                 // ignored
             } catch (e: Exception) {
                 e.printStackTrace()
+            } finally {
+                MiraiConsoleImplementation.instance = null
             }
         }
     }