Migrate JSPackagerClientTest to Kotlin (#37747)

Summary:
Migrate [JSPackagerClientTest.java](https://github.com/facebook/react-native/blob/main/packages/react-native/ReactAndroid/src/test/java/com/facebook/react/packagerconnection/JSPackagerClientTest.java) to Kotlin.  See #37708

## Changelog:

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[INTERNAL] [CHANGED] - Migrate JSPackagerClientTest to Kotlin

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[INTERNAL] [CHANGED] - Migrate JSPackagerClientTest to Kotlin

Pull Request resolved: #37747

Test Plan:
Tests pass: ./gradlew :packages:react-native:ReactAndroid:test
Formatted with [KtFmt](https://facebook.github.io/ktfmt/)

Reviewed By: cortinico

Differential Revision: D46514210

Pulled By: rshest

fbshipit-source-id: ecec18a69b1401214e22c6cbea34d49528da1a79

packages/react-native/ReactAndroid/src/test/java/com/facebook/react/packagerconnection/JSPackagerClientTest.kt

@@ -0,0 +1,150 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.react.packagerconnection
+
+import com.facebook.react.packagerconnection.ReconnectingWebSocket.ConnectionCallback
+import java.io.IOException
+import okio.ByteString
+import okio.ByteString.encodeUtf8
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.ArgumentMatchers
+import org.mockito.Mockito.*
+import org.mockito.Mockito.`when` as whenever
+import org.robolectric.RobolectricTestRunner
+
+@RunWith(RobolectricTestRunner::class)
+class JSPackagerClientTest {
+
+  private lateinit var settings: PackagerConnectionSettings
+
+  @Before
+  fun setup() {
+    settings = mock(PackagerConnectionSettings::class.java)
+    whenever(settings.debugServerHost).thenReturn("ws://not_needed")
+    whenever(settings.packageName).thenReturn("my_test_package")
+  }
+
+  @Test
+  @Throws(IOException::class)
+  fun test_onMessage_ShouldTriggerNotification() {
+    val handler = mock(RequestHandler::class.java)
+    val client = getClient(createRequestHandler("methodValue", handler))
+
+    client.onMessage("""{"version": 2, "method": "methodValue", "params": "paramsValue"}""")
+    verify(handler).onNotification(eq("paramsValue"))
+    verify(handler, never()).onRequest(any(), any(Responder::class.java))
+  }
+
+  @Test
+  @Throws(IOException::class)
+  fun test_onMessage_ShouldTriggerRequest() {
+    val handler = mock(RequestHandler::class.java)
+    val client = getClient(createRequestHandler("methodValue", handler))
+
+    client.onMessage(
+        """{"version": 2, "id": "idValue", "method": "methodValue", "params": "paramsValue"}""")
+    verify(handler, never()).onNotification(any())
+    verify(handler).onRequest(eq("paramsValue"), any(Responder::class.java))
+  }
+
+  @Test
+  @Throws(IOException::class)
+  fun test_onMessage_WithoutParams_ShouldTriggerNotification() {
+    val handler = mock(RequestHandler::class.java)
+    val client = getClient(createRequestHandler("methodValue", handler))
+
+    client.onMessage("""{"version": 2, "method": "methodValue"}""")
+    verify(handler).onNotification(ArgumentMatchers.isNull())
+    verify(handler, never()).onRequest(any(), any(Responder::class.java))
+  }
+
+  @Test
+  @Throws(IOException::class)
+  fun test_onMessage_WithInvalidContentType_ShouldNotTriggerCallback() {
+    val handler = mock(RequestHandler::class.java)
+    val client = getClient(createRequestHandler("methodValue", handler))
+
+    client.onMessage(encodeUtf8("""{"version": 2, "method": "methodValue"}"""))
+    verify(handler, never()).onNotification(any())
+    verify(handler, never()).onRequest(any(), any(Responder::class.java))
+  }
+
+  @Test
+  @Throws(IOException::class)
+  fun test_onMessage_WithoutMethod_ShouldNotTriggerCallback() {
+    val handler = mock(RequestHandler::class.java)
+    val client = getClient(createRequestHandler("methodValue", handler))
+
+    client.onMessage("""{"version": 2}""")
+    verify(handler, never()).onNotification(any())
+    verify(handler, never()).onRequest(any(), any(Responder::class.java))
+  }
+
+  @Test
+  @Throws(IOException::class)
+  fun test_onMessage_With_Null_Action_ShouldNotTriggerCallback() {
+    val handler = mock(RequestHandler::class.java)
+    val client = getClient(createRequestHandler("methodValue", handler))
+
+    client.onMessage("""{"version": 2, "method": null}""")
+    verify(handler, never()).onNotification(any())
+    verify(handler, never()).onRequest(any(), any(Responder::class.java))
+  }
+
+  @Test
+  @Throws(IOException::class)
+  fun test_onMessage_WithInvalidMethod_ShouldNotTriggerCallback() {
+    val handler = mock(RequestHandler::class.java)
+    val client = getClient(createRequestHandler("methodValue", handler))
+
+    client.onMessage(ByteString.EMPTY)
+    verify(handler, never()).onNotification(any())
+    verify(handler, never()).onRequest(any(), any(Responder::class.java))
+  }
+
+  @Test
+  @Throws(IOException::class)
+  fun test_onMessage_WrongVersion_ShouldNotTriggerCallback() {
+    val handler = mock(RequestHandler::class.java)
+    val client = getClient(createRequestHandler("methodValue", handler))
+
+    client.onMessage("""{"version": 1, "method": "methodValue"}""")
+    verify(handler, never()).onNotification(any())
+    verify(handler, never()).onRequest(any(), any(Responder::class.java))
+  }
+
+  @Test
+  @Throws(IOException::class)
+  fun test_onDisconnection_ShouldTriggerDisconnectionCallback() {
+    val connectionHandler = mock(ConnectionCallback::class.java)
+    val handler = mock(RequestHandler::class.java)
+    val client = getClient(requestHandlers = emptyMap(), connectionCallback = connectionHandler)
+
+    client.close()
+
+    verify(connectionHandler, never()).onConnected()
+    verify(connectionHandler, times(1)).onDisconnected()
+
+    verify(handler, never()).onNotification(any())
+    verify(handler, never()).onRequest(any(), any(Responder::class.java))
+  }
+
+  private fun getClient(
+      requestHandlers: Map<String, RequestHandler>,
+      clientId: String = "test_client",
+      settings: PackagerConnectionSettings = this.settings,
+      connectionCallback: ConnectionCallback? = null
+  ): JSPackagerClient = JSPackagerClient(clientId, settings, requestHandlers, connectionCallback)
+
+  private fun createRequestHandler(
+      action: String,
+      handler: RequestHandler
+  ): Map<String, RequestHandler> = mapOf(action to handler)
+}