feat: Support onClientRequest in snaps-jest (#3445)

Add support for `onClientRequest` in `snaps-jest` to ease testing of
internal Snap functionality.

Closes #3401

Author: FrederikBolding

packages/snaps-jest/src/helpers.ts

@@ -189,6 +189,7 @@ export async function installSnap<
     onUpdate,
     onNameLookup,
     onProtocolRequest,
+    onClientRequest,
     mockJsonRpc,
     close,
   } = await getEnvironment().installSnap(...resolvedOptions);
@@ -209,6 +210,7 @@ export async function installSnap<
     onUpdate,
     onNameLookup,
     onProtocolRequest,
+    onClientRequest,
     mockJsonRpc,
     close: async () => {
       log('Closing execution service.');

packages/snaps-simulation/src/helpers.test.tsx

@@ -761,6 +761,34 @@ describe('helpers', () => {
     });
   });
 
+  describe('onClientRequest', () => {
+    it('sends a onClientRequest request and returns the result', async () => {
+      jest.spyOn(console, 'log').mockImplementation();
+
+      const { snapId, close: closeServer } = await getMockServer({
+        sourceCode: `
+          module.exports.onClientRequest = async ({ request }) => {
+            return request.method;
+          };
+         `,
+      });
+
+      const { onClientRequest, close } = await installSnap(snapId);
+      const response = await onClientRequest({ method: 'foo' });
+
+      expect(response).toStrictEqual(
+        expect.objectContaining({
+          response: {
+            result: 'foo',
+          },
+        }),
+      );
+
+      await close();
+      await closeServer();
+    });
+  });
+
   describe('mockJsonRpc', () => {
     it('mocks a JSON-RPC method', async () => {
       jest.spyOn(console, 'log').mockImplementation();

packages/snaps-simulation/src/helpers.ts

@@ -180,6 +180,14 @@ export type SnapHelpers = {
     request: RequestOptions,
   ): Promise<SnapResponseWithoutInterface>;
 
+  /**
+   * Send a JSON-RPC client request to the Snap.
+   *
+   * @param request - The JSON-RPC request.
+   * @returns The response promise, with extra {@link SnapRequestObject} fields.
+   */
+  onClientRequest(request: Omit<RequestOptions, 'origin'>): SnapRequest;
+
   /**
    * Mock a JSON-RPC request. This will cause the snap to respond with the
    * specified response when a request with the specified method is sent.
@@ -491,6 +499,22 @@ export function getHelpers({
       return response;
     },
 
+    // This can't be async because it returns a `SnapRequest`.
+    // eslint-disable-next-line @typescript-eslint/promise-function-async
+    onClientRequest: (request) => {
+      log('Sending client request.');
+
+      return handleRequest({
+        snapId,
+        store,
+        executionService,
+        controllerMessenger,
+        runSaga,
+        handler: HandlerType.OnClientRequest,
+        request,
+      });
+    },
+
     mockJsonRpc(mock: JsonRpcMockOptions) {
       log('Mocking JSON-RPC request %o.', mock);
 

packages/snaps-simulation/src/types.ts

@@ -514,6 +514,14 @@ export type Snap = {
     request: RequestOptions,
   ): Promise<SnapResponseWithoutInterface>;
 
+  /**
+   * Send a JSON-RPC client request to the Snap.
+   *
+   * @param request - The JSON-RPC request.
+   * @returns The response promise, with extra {@link SnapRequestObject} fields.
+   */
+  onClientRequest(request: Omit<RequestOptions, 'origin'>): SnapRequest;
+
   /**
    * Mock a JSON-RPC request. This will cause the snap to respond with the
    * specified response when a request with the specified method is sent.