Add getProviderConfig action to NetworkController (#19317)

This controller action exists within the core version of
NetworkController. Although there are no plans to make use of this
action within the extension, it has accompanying tests. So ultimately,
the goal of this commit (like others) is to make it easier to compare
differences in the NetworkController tests between this repo and core
by adding a test for the `getProviderConfig` action.

app/scripts/controllers/network/network-controller.test.ts

@@ -18,6 +18,7 @@ import {
 import { MetaMetricsNetworkEventSource } from '../../../../shared/constants/metametrics';
 import {
   NetworkController,
+  NetworkControllerAction,
   NetworkControllerEvent,
   NetworkControllerOptions,
   NetworkControllerState,
@@ -2451,6 +2452,31 @@ describe('NetworkController', () => {
     });
   });
 
+  describe('NetworkController:getProviderConfig action', () => {
+    it('returns the provider config in state', async () => {
+      await withController(
+        {
+          state: {
+            providerConfig: buildProviderConfig({
+              type: NETWORK_TYPES.MAINNET,
+            }),
+          },
+        },
+        async ({ messenger }) => {
+          const providerConfig = await messenger.call(
+            'NetworkController:getProviderConfig',
+          );
+
+          expect(providerConfig).toStrictEqual(
+            buildProviderConfig({
+              type: NETWORK_TYPES.MAINNET,
+            }),
+          );
+        },
+      );
+    });
+  });
+
   describe('rollbackToPreviousProvider', () => {
     for (const { networkType } of INFURA_NETWORKS) {
       describe(`if the previous provider configuration had a type of "${networkType}"`, () => {
@@ -6088,7 +6114,10 @@ function lookupNetworkTests({
  * @returns The controller messenger.
  */
 function buildMessenger() {
-  return new ControllerMessenger<never, NetworkControllerEvent>();
+  return new ControllerMessenger<
+    NetworkControllerAction,
+    NetworkControllerEvent
+  >();
 }
 
 /**
@@ -6100,6 +6129,7 @@ function buildMessenger() {
 function buildNetworkControllerMessenger(messenger = buildMessenger()) {
   return messenger.getRestricted({
     name: 'NetworkController',
+    allowedActions: ['NetworkController:getProviderConfig'],
     allowedEvents: [
       'NetworkController:networkDidChange',
       'NetworkController:networkWillChange',
@@ -6116,7 +6146,10 @@ type WithControllerCallback<ReturnValue> = ({
   controller,
 }: {
   controller: NetworkController;
-  messenger: ControllerMessenger<never, NetworkControllerEvent>;
+  messenger: ControllerMessenger<
+    NetworkControllerAction,
+    NetworkControllerEvent
+  >;
 }) => Promise<ReturnValue> | ReturnValue;
 
 /**

app/scripts/controllers/network/network-controller.ts

@@ -130,12 +130,19 @@ export type NetworkControllerEvent =
   | NetworkControllerInfuraIsBlockedEvent
   | NetworkControllerInfuraIsUnblockedEvent;
 
+export type NetworkControllerGetProviderConfigAction = {
+  type: `NetworkController:getProviderConfig`;
+  handler: () => ProviderConfiguration;
+};
+
+export type NetworkControllerAction = NetworkControllerGetProviderConfigAction;
+
 /**
  * The messenger that the NetworkController uses to publish events.
  */
 export type NetworkControllerMessenger = RestrictedControllerMessenger<
   typeof name,
-  never,
+  NetworkControllerAction,
   NetworkControllerEvent,
   string,
   string
@@ -477,6 +484,9 @@ export class NetworkController extends EventEmitter {
     }
     this.#infuraProjectId = infuraProjectId;
     this.#trackMetaMetricsEvent = trackMetaMetricsEvent;
+    this.#messenger.registerActionHandler(`${name}:getProviderConfig`, () => {
+      return this.store.getState().providerConfig;
+    });
   }
 
   /**