fix: Ensure json-rpc-engine/v2 can be resolved without builds

Author: rekmarks

jest.config.packages.js

@@ -80,6 +80,9 @@ module.exports = {
   // Here we ensure that Jest resolves `@metamask/*` imports to the uncompiled source code for packages that live in this repo.
   // NOTE: This must be synchronized with the `paths` option in `tsconfig.packages.json`.
   moduleNameMapper: {
+    '^@metamask/json-rpc-engine/v2$': [
+      '<rootDir>/../json-rpc-engine/src/v2/index.ts',
+    ],
     '^@metamask/(.+)$': [
       '<rootDir>/../$1/src',
       // Some @metamask/* packages we are referencing aren't in this monorepo,

packages/eth-json-rpc-provider/src/internal-provider.test.ts

@@ -2,6 +2,7 @@ import { Web3Provider } from '@ethersproject/providers';
 import EthQuery from '@metamask/eth-query';
 import EthJsQuery from '@metamask/ethjs-query';
 import { JsonRpcEngine } from '@metamask/json-rpc-engine';
+import type { JsonRpcMiddleware } from '@metamask/json-rpc-engine/v2';
 import { JsonRpcEngineV2, JsonRpcServer } from '@metamask/json-rpc-engine/v2';
 import { providerErrors } from '@metamask/rpc-errors';
 import { type JsonRpcRequest, type Json } from '@metamask/utils';
@@ -32,7 +33,7 @@ const createEngine = (method: string, result: ResultParam) => {
 };
 
 const createServer = (method: string, result: ResultParam) => {
-  const engine = JsonRpcEngineV2.create({
+  const engine = JsonRpcEngineV2.create<JsonRpcMiddleware<JsonRpcRequest>>({
     middleware: [
       ({ request, next }) => {
         if (request.method === method) {
@@ -44,8 +45,7 @@ const createServer = (method: string, result: ResultParam) => {
       },
     ],
   });
-  const server = new JsonRpcServer({ engine });
-  return server;
+  return new JsonRpcServer<JsonRpcMiddleware<JsonRpcRequest>>({ engine });
 };
 
 describe('legacy constructor', () => {

packages/eth-json-rpc-provider/src/internal-provider.ts

@@ -1,5 +1,8 @@
 import type { JsonRpcEngine } from '@metamask/json-rpc-engine';
-import type { JsonRpcServer } from '@metamask/json-rpc-engine/v2';
+import type {
+  JsonRpcMiddleware,
+  JsonRpcServer,
+} from '@metamask/json-rpc-engine/v2';
 import { JsonRpcError } from '@metamask/rpc-errors';
 import type { JsonRpcFailure } from '@metamask/utils';
 import {
@@ -31,7 +34,9 @@ type Options =
       engine: JsonRpcEngine;
     }
   | {
-      rpcHandler: JsonRpcEngine | JsonRpcServer;
+      rpcHandler:
+        | JsonRpcEngine
+        | JsonRpcServer<JsonRpcMiddleware<JsonRpcRequest>>;
     };
 
 /**
@@ -41,7 +46,9 @@ type Options =
  * It is not compliant with any Ethereum provider standard.
  */
 export class InternalProvider {
-  readonly #rpcHandler: JsonRpcEngine | JsonRpcServer;
+  readonly #rpcHandler:
+    | JsonRpcEngine
+    | JsonRpcServer<JsonRpcMiddleware<JsonRpcRequest>>;
 
   /**
    * Construct a InternalProvider from a JSON-RPC server or legacy engine.

packages/eth-json-rpc-provider/src/provider-from-middleware.ts

@@ -31,11 +31,8 @@ export function providerFromMiddleware<
  * @returns An Ethereum provider.
  */
 export function providerFromMiddlewareV2<
-  Params extends JsonRpcParams,
-  Result extends Json,
->(
-  middleware: JsonRpcMiddleware<JsonRpcRequest<Params>, Result>,
-): InternalProvider {
+  Middleware extends JsonRpcMiddleware<JsonRpcRequest, Json>,
+>(middleware: Middleware): InternalProvider {
   return new InternalProvider({
     rpcHandler: new JsonRpcServer({ middleware: [middleware] }),
   });

tsconfig.packages.json

@@ -13,6 +13,7 @@
      * `jest.config.packages.js`.
      */
     "paths": {
+      "@metamask/json-rpc-engine/v2": ["../json-rpc-engine/src/v2/index.ts"],
       "@metamask/*": ["../*/src"]
     },
     "strict": true,