Allow debug dev server port override

This commit removes the hardcoded instances of port 8081 on Android
with a build configuration property. This allows setting of the port
React Native Android connects to for the local build server.

For this change to work, there must also be an update to the react
native CLI to pass along this setting.

Related issues:
facebook#9145

ReactAndroid/build.gradle

@@ -203,6 +203,11 @@ def findNdkBuildFullPath() {
     return null
 }
 
+def debugHostPort(String defaultValue){
+    def value = project.getProperties().get("debugHostPort")
+    return value != null ? value : defaultValue
+}
+
 def getNdkBuildFullPath() {
     def ndkBuildFullPath = findNdkBuildFullPath()
     if (ndkBuildFullPath == null) {
@@ -289,6 +294,8 @@ android {
 
         buildConfigField("boolean", "IS_INTERNAL_BUILD", "false")
         buildConfigField("int", "EXOPACKAGE_FLAGS", "0")
+        buildConfigField("int", "DEBUG_SERVER_HOST_PORT", debugHostPort("8081"))
+
         testApplicationId("com.facebook.react.tests.gradle")
         testInstrumentationRunner("androidx.test.runner.AndroidJUnitRunner")
     }

ReactAndroid/src/main/java/com/facebook/react/common/BUCK

@@ -38,6 +38,7 @@ rn_android_build_config(
     package = "com.facebook.react",
     values = [
         "boolean IS_INTERNAL_BUILD = true",
+        "int DEBUG_SERVER_HOST_PORT = 8081",
     ],
     visibility = [
         "PUBLIC",

ReactAndroid/src/main/java/com/facebook/react/common/DebugServerException.java

@@ -18,6 +18,8 @@
 import org.json.JSONException;
 import org.json.JSONObject;
 
+import static com.facebook.react.common.build.ReactBuildConfig.DEBUG_SERVER_HOST_PORT;
+
 /**
  * Tracks errors connecting to or received from the debug server.
  * The debug server returns errors as json objects. This exception represents that error.
@@ -28,8 +30,8 @@ public class DebugServerException extends RuntimeException {
       "\u2022 Ensure that the packager server is running\n" +
       "\u2022 Ensure that your device/emulator is connected to your machine and has USB debugging enabled - run 'adb devices' to see a list of connected devices\n" +
       "\u2022 Ensure Airplane Mode is disabled\n" +
-      "\u2022 If you're on a physical device connected to the same machine, run 'adb reverse tcp:8081 tcp:8081' to forward requests from your device\n" +
-      "\u2022 If your device is on the same Wi-Fi network, set 'Debug server host & port for device' in 'Dev settings' to your machine's IP address and the port of the local dev server - e.g. 10.0.1.1:8081\n\n";
+      "\u2022 If you're on a physical device connected to the same machine, run 'adb reverse tcp:" + DEBUG_SERVER_HOST_PORT + " tcp:" + DEBUG_SERVER_HOST_PORT + "' to forward requests from your device\n" +
+      "\u2022 If your device is on the same Wi-Fi network, set 'Debug server host & port for device' in 'Dev settings' to your machine's IP address and the port of the local dev server - e.g. 10.0.1.1:" + DEBUG_SERVER_HOST_PORT + "\n\n";
 
   public static DebugServerException makeGeneric(String reason, Throwable t) {
     return makeGeneric(reason, "", t);

ReactAndroid/src/main/java/com/facebook/react/common/build/ReactBuildConfig.java

@@ -20,4 +20,6 @@ public class ReactBuildConfig {
   public static final boolean DEBUG = BuildConfig.DEBUG;
   public static final boolean IS_INTERNAL_BUILD = BuildConfig.IS_INTERNAL_BUILD;
   public static final int EXOPACKAGE_FLAGS = BuildConfig.EXOPACKAGE_FLAGS;
+  public static final int DEBUG_SERVER_HOST_PORT = BuildConfig.DEBUG_SERVER_HOST_PORT;
+
 }

ReactAndroid/src/main/java/com/facebook/react/modules/systeminfo/AndroidInfoHelpers.java

@@ -14,6 +14,7 @@
 import android.os.Build;
 
 import com.facebook.common.logging.FLog;
+import com.facebook.react.common.build.ReactBuildConfig;
 
 public class AndroidInfoHelpers {
 
@@ -23,7 +24,7 @@ public class AndroidInfoHelpers {
 
   public static final String METRO_HOST_PROP_NAME = "metro.host";
 
-  private static final int DEBUG_SERVER_HOST_PORT = 8081;
+  private static final int DEBUG_SERVER_HOST_PORT = ReactBuildConfig.DEBUG_SERVER_HOST_PORT;
   private static final int INSPECTOR_PROXY_PORT = 8081;
 
   private static final String TAG = AndroidInfoHelpers.class.getSimpleName();
@@ -40,6 +41,10 @@ public static String getServerHost() {
     return getServerIpAddress(DEBUG_SERVER_HOST_PORT);
   }
 
+  public static String getAdbReverseTcpCommand() {
+    return "adb reverse tcp:" + DEBUG_SERVER_HOST_PORT + " tcp:" + DEBUG_SERVER_HOST_PORT;
+  }
+
   public static String getInspectorProxyHost() {
     return getServerIpAddress(INSPECTOR_PROXY_PORT);
   }

ReactAndroid/src/main/java/com/facebook/react/modules/systeminfo/BUCK

@@ -29,6 +29,7 @@ rn_android_library(
         "PUBLIC",
     ],
     deps = [
+        react_native_target("java/com/facebook/react/common:common"),
         react_native_dep("libraries/fbcore/src/main/java/com/facebook/common/logging:logging"),
         react_native_dep("third-party/java/infer-annotations:infer-annotations"),
         react_native_dep("third-party/java/jsr-305:jsr-305"),

ReactAndroid/src/main/java/com/facebook/react/packagerconnection/PackagerConnectionSettings.java

@@ -44,7 +44,7 @@ public String getDebugServerHost() {
     if (host.equals(AndroidInfoHelpers.DEVICE_LOCALHOST)) {
       FLog.w(
         TAG,
-        "You seem to be running on device. Run 'adb reverse tcp:8081 tcp:8081' " +
+        "You seem to be running on device. Run '" + AndroidInfoHelpers.getAdbReverseTcpCommand() + "' " +
           "to forward the debug server's port to the device.");
     }