Add experiment to configure internal debugger branding (#44388)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/44388

Towards the open source rollout of the `rn_fusebox.ts` entry point.

NOTE: Requires https://github.com/facebookexperimental/rn-chrome-devtools-frontend/pull/59, but can (and should) be landed safely beforehand.

Changelog: [Internal]

Reviewed By: motiz88

Differential Revision: D56883040

fbshipit-source-id: acee5d53c0f93ef9dc2d498001291b1e35237824

packages/dev-middleware/src/__tests__/getDevToolsFrontendUrl-test.js

@@ -20,6 +20,7 @@ describe('getDevToolsFrontendUrl', () => {
     enableNetworkInspector: false,
     enableNewDebugger: false,
     enableOpenDebuggerRedirect: false,
+    useFuseboxInternalBranding: false,
   };
 
   describe('relative: false, launchId: undefined (default)', () => {

packages/dev-middleware/src/createDevMiddleware.js

@@ -129,5 +129,6 @@ function getExperiments(config: ExperimentsConfig): Experiments {
     enableNewDebugger: config.enableNewDebugger ?? false,
     enableOpenDebuggerRedirect: config.enableOpenDebuggerRedirect ?? false,
     enableNetworkInspector: config.enableNetworkInspector ?? false,
+    useFuseboxInternalBranding: config.useFuseboxInternalBranding ?? false,
   };
 }

packages/dev-middleware/src/types/Experiments.js

@@ -28,6 +28,12 @@ export type Experiments = $ReadOnly<{
    * Enables the Network panel when launching the custom debugger frontend.
    */
   enableNetworkInspector: boolean,
+
+  /**
+   * [Meta-internal] Controls visibility of the internal "Fusebox" codename
+   * across the UI when using the modern `rn_fusebox` entry point.
+   */
+  useFuseboxInternalBranding: boolean,
 }>;
 
 export type ExperimentsConfig = Partial<Experiments>;

packages/dev-middleware/src/utils/getDevToolsFrontendUrl.js

@@ -44,6 +44,12 @@ export default function getDevToolsFrontendUrl(
   if (experiments.enableNetworkInspector) {
     searchParams.append('unstable_enableNetworkPanel', 'true');
   }
+  if (
+    options?.useFuseboxEntryPoint === true &&
+    experiments.useFuseboxInternalBranding
+  ) {
+    searchParams.append('unstable_useInternalBranding', 'true');
+  }
   if (options?.launchId != null && options.launchId !== '') {
     searchParams.append('launchId', options.launchId);
   }