BREAKING: Use @metamask/utils (#105)

Replace various utility types and functions with implementations copied over to `@metamask/utils`. Functionality should be practically identical.

The one possible deviation is that two `in` checks have been replaced with `hasProperty`, which does not walk the prototype chain. This should not be breaking for our purposes.

Author: rekmarks

package.json

@@ -32,6 +32,7 @@
   },
   "dependencies": {
     "@metamask/safe-event-emitter": "^2.0.0",
+    "@metamask/utils": "^2.0.0",
     "eth-rpc-errors": "^4.0.2"
   },
   "devDependencies": {

src/JsonRpcEngine.ts

@@ -1,69 +1,19 @@
 import SafeEventEmitter from '@metamask/safe-event-emitter';
+import {
+  hasProperty,
+  JsonRpcError,
+  JsonRpcRequest,
+  JsonRpcResponse,
+} from '@metamask/utils';
 import { errorCodes, EthereumRpcError, serializeError } from 'eth-rpc-errors';
 
-type Maybe<T> = Partial<T> | null | undefined;
-
-export type Json =
-  | boolean
-  | number
-  | string
-  | null
-  | { [property: string]: Json }
-  | Json[];
-
-/**
- * A String specifying the version of the JSON-RPC protocol.
- * MUST be exactly "2.0".
- */
-export type JsonRpcVersion = '2.0';
-
-/**
- * An identifier established by the Client that MUST contain a String, Number,
- * or NULL value if included. If it is not included it is assumed to be a
- * notification. The value SHOULD normally not be Null and Numbers SHOULD
- * NOT contain fractional parts.
- */
-export type JsonRpcId = number | string | null;
-
-export interface JsonRpcError {
-  code: number;
-  message: string;
-  data?: unknown;
-  stack?: string;
-}
-
-export interface JsonRpcRequest<T> {
-  jsonrpc: JsonRpcVersion;
-  method: string;
-  id: JsonRpcId;
-  params?: T;
-}
-
-export interface JsonRpcNotification<T> {
-  jsonrpc: JsonRpcVersion;
-  method: string;
-  params?: T;
-}
-
-interface JsonRpcResponseBase {
-  jsonrpc: JsonRpcVersion;
-  id: JsonRpcId;
-}
-
-export interface JsonRpcSuccess<T> extends JsonRpcResponseBase {
-  result: Maybe<T>;
-}
-
-export interface JsonRpcFailure extends JsonRpcResponseBase {
-  error: JsonRpcError;
-}
-
-export type JsonRpcResponse<T> = JsonRpcSuccess<T> | JsonRpcFailure;
-
-export interface PendingJsonRpcResponse<T> extends JsonRpcResponseBase {
-  result?: T;
-  error?: Error | JsonRpcError;
-}
+export type PendingJsonRpcResponse<Result> = Omit<
+  JsonRpcResponse<Result>,
+  'error' | 'result'
+> & {
+  result?: Result;
+  error?: JsonRpcError;
+};
 
 export type JsonRpcEngineCallbackError = Error | JsonRpcError | null;
 
@@ -79,9 +29,9 @@ export type JsonRpcEngineEndCallback = (
   error?: JsonRpcEngineCallbackError,
 ) => void;
 
-export type JsonRpcMiddleware<T, U> = (
-  req: JsonRpcRequest<T>,
-  res: PendingJsonRpcResponse<U>,
+export type JsonRpcMiddleware<Params, Result> = (
+  req: JsonRpcRequest<Params>,
+  res: PendingJsonRpcResponse<Result>,
   next: JsonRpcEngineNextCallback,
   end: JsonRpcEngineEndCallback,
 ) => void;
@@ -103,7 +53,7 @@ export class JsonRpcEngine extends SafeEventEmitter {
    *
    * @param middleware - The middleware function to add.
    */
-  push<T, U>(middleware: JsonRpcMiddleware<T, U>): void {
+  push<Params, Result>(middleware: JsonRpcMiddleware<Params, Result>): void {
     this._middleware.push(middleware as JsonRpcMiddleware<unknown, unknown>);
   }
 
@@ -113,9 +63,9 @@ export class JsonRpcEngine extends SafeEventEmitter {
    * @param request - The request to handle.
    * @param callback - An error-first callback that will receive the response.
    */
-  handle<T, U>(
-    request: JsonRpcRequest<T>,
-    callback: (error: unknown, response: JsonRpcResponse<U>) => void,
+  handle<Params, Result>(
+    request: JsonRpcRequest<Params>,
+    callback: (error: unknown, response: JsonRpcResponse<Result>) => void,
   ): void;
 
   /**
@@ -125,9 +75,9 @@ export class JsonRpcEngine extends SafeEventEmitter {
    * @param callback - An error-first callback that will receive the array of
    * responses.
    */
-  handle<T, U>(
-    requests: JsonRpcRequest<T>[],
-    callback: (error: unknown, responses: JsonRpcResponse<U>[]) => void,
+  handle<Params, Result>(
+    requests: JsonRpcRequest<Params>[],
+    callback: (error: unknown, responses: JsonRpcResponse<Result>[]) => void,
   ): void;
 
   /**
@@ -136,15 +86,19 @@ export class JsonRpcEngine extends SafeEventEmitter {
    * @param request - The JSON-RPC request to handle.
    * @returns The JSON-RPC response.
    */
-  handle<T, U>(request: JsonRpcRequest<T>): Promise<JsonRpcResponse<U>>;
+  handle<Params, Result>(
+    request: JsonRpcRequest<Params>,
+  ): Promise<JsonRpcResponse<Result>>;
 
   /**
    * Handle an array of JSON-RPC requests, and return an array of responses.
    *
    * @param request - The JSON-RPC requests to handle.
    * @returns An array of JSON-RPC responses.
    */
-  handle<T, U>(requests: JsonRpcRequest<T>[]): Promise<JsonRpcResponse<U>[]>;
+  handle<Params, Result>(
+    requests: JsonRpcRequest<Params>[],
+  ): Promise<JsonRpcResponse<Result>[]>;
 
   handle(req: unknown, callback?: any) {
     if (callback && typeof callback !== 'function') {
@@ -487,7 +441,7 @@ export class JsonRpcEngine extends SafeEventEmitter {
     res: PendingJsonRpcResponse<unknown>,
     isComplete: boolean,
   ): void {
-    if (!('result' in res) && !('error' in res)) {
+    if (!hasProperty(res, 'result') && !hasProperty(res, 'error')) {
       throw new EthereumRpcError(
         errorCodes.rpc.internal,
         `JsonRpcEngine: Response has no error or result for request:\n${jsonify(

src/asMiddleware.test.ts

@@ -1,9 +1,9 @@
 import {
   assertIsJsonRpcSuccess,
   isJsonRpcSuccess,
-  JsonRpcEngine,
   JsonRpcRequest,
-} from '.';
+} from '@metamask/utils';
+import { JsonRpcEngine } from '.';
 
 const jsonrpc = '2.0' as const;
 

src/createAsyncMiddleware.test.ts

@@ -1,8 +1,5 @@
-import {
-  JsonRpcEngine,
-  createAsyncMiddleware,
-  assertIsJsonRpcSuccess,
-} from '.';
+import { assertIsJsonRpcSuccess } from '@metamask/utils';
+import { JsonRpcEngine, createAsyncMiddleware } from '.';
 
 const jsonrpc = '2.0' as const;
 

src/createAsyncMiddleware.ts

@@ -1,14 +1,11 @@
-import {
-  JsonRpcMiddleware,
-  JsonRpcRequest,
-  PendingJsonRpcResponse,
-} from './JsonRpcEngine';
+import { JsonRpcRequest } from '@metamask/utils';
+import { JsonRpcMiddleware, PendingJsonRpcResponse } from './JsonRpcEngine';
 
 export type AsyncJsonRpcEngineNextCallback = () => Promise<void>;
 
-export type AsyncJsonrpcMiddleware<T, U> = (
-  req: JsonRpcRequest<T>,
-  res: PendingJsonRpcResponse<U>,
+export type AsyncJsonrpcMiddleware<Params, Result> = (
+  req: JsonRpcRequest<Params>,
+  res: PendingJsonRpcResponse<Result>,
   next: AsyncJsonRpcEngineNextCallback,
 ) => Promise<void>;
 
@@ -35,9 +32,9 @@ type ReturnHandlerCallback = (error: null | Error) => void;
  * @returns The wrapped asynchronous middleware function, ready to be consumed
  * by JsonRpcEngine.
  */
-export function createAsyncMiddleware<T, U>(
-  asyncMiddleware: AsyncJsonrpcMiddleware<T, U>,
-): JsonRpcMiddleware<T, U> {
+export function createAsyncMiddleware<Params, Result>(
+  asyncMiddleware: AsyncJsonrpcMiddleware<Params, Result>,
+): JsonRpcMiddleware<Params, Result> {
   return async (req, res, next, end) => {
     // nextPromise is the key to the implementation
     // it is resolved by the return handler passed to the

src/createScaffoldMiddleware.test.ts

@@ -1,10 +1,9 @@
 import {
-  JsonRpcEngine,
-  createScaffoldMiddleware,
-  JsonRpcMiddleware,
   assertIsJsonRpcSuccess,
   assertIsJsonRpcFailure,
-} from '.';
+} from '@metamask/utils';
+import { ethErrors } from 'eth-rpc-errors';
+import { JsonRpcEngine, createScaffoldMiddleware, JsonRpcMiddleware } from '.';
 
 describe('createScaffoldMiddleware', () => {
   it('basic middleware test', async () => {
@@ -20,7 +19,7 @@ describe('createScaffoldMiddleware', () => {
         end();
       },
       method3: (_req, res, _next, end) => {
-        res.error = new Error('method3');
+        res.error = ethErrors.rpc.internal({ message: 'method3' });
         end();
       },
     };

src/createScaffoldMiddleware.ts

@@ -1,6 +1,9 @@
-import { Json, JsonRpcMiddleware, JsonRpcSuccess } from './JsonRpcEngine';
+import { Json, JsonRpcSuccess } from '@metamask/utils';
+import { JsonRpcMiddleware } from './JsonRpcEngine';
 
-type ScaffoldMiddlewareHandler<T, U> = JsonRpcMiddleware<T, U> | Json;
+type ScaffoldMiddlewareHandler<Params, Result> =
+  | JsonRpcMiddleware<Params, Result>
+  | Json;
 
 /**
  * Creates a middleware function from an object of RPC method handler functions,

src/engine.test.ts

@@ -1,9 +1,11 @@
-import { isJsonRpcFailure, isJsonRpcSuccess } from './utils';
 import {
-  JsonRpcEngine,
   assertIsJsonRpcSuccess,
   assertIsJsonRpcFailure,
-} from '.';
+  isJsonRpcFailure,
+  isJsonRpcSuccess,
+} from '@metamask/utils';
+import { ethErrors } from 'eth-rpc-errors';
+import { JsonRpcEngine } from '.';
 
 const jsonrpc = '2.0' as const;
 
@@ -187,7 +189,7 @@ describe('JsonRpcEngine', () => {
     const engine = new JsonRpcEngine();
 
     engine.push(function (_req, res, next, _end) {
-      res.error = new Error('no bueno');
+      res.error = ethErrors.rpc.internal({ message: 'foobar' });
       next();
     });
 
@@ -208,7 +210,7 @@ describe('JsonRpcEngine', () => {
     const engine = new JsonRpcEngine();
 
     engine.push(function (_req, res, _next, end) {
-      res.error = new Error('no bueno');
+      res.error = ethErrors.rpc.internal({ message: 'foobar' });
       end();
     });
 
@@ -270,7 +272,7 @@ describe('JsonRpcEngine', () => {
     engine.push(function (req, res, _next, end) {
       if (req.id === 4) {
         delete res.result;
-        res.error = new Error('foobar');
+        res.error = ethErrors.rpc.internal({ message: 'foobar' });
         return end(res.error);
       }
       res.result = req.id;
@@ -305,7 +307,7 @@ describe('JsonRpcEngine', () => {
     engine.push(function (req, res, _next, end) {
       if (req.id === 4) {
         delete res.result;
-        res.error = new Error('foobar');
+        res.error = ethErrors.rpc.internal({ message: 'foobar' });
         return end(res.error);
       }
       res.result = req.id;

src/index.ts

@@ -4,4 +4,3 @@ export * from './getUniqueId';
 export * from './idRemapMiddleware';
 export * from './JsonRpcEngine';
 export * from './mergeMiddleware';
-export * from './utils';

src/mergeMiddleware.test.ts

@@ -1,9 +1,9 @@
 import {
   assertIsJsonRpcSuccess,
-  JsonRpcEngine,
+  hasProperty,
   JsonRpcRequest,
-  mergeMiddleware,
-} from '.';
+} from '@metamask/utils';
+import { JsonRpcEngine, mergeMiddleware } from '.';
 
 const jsonrpc = '2.0' as const;
 
@@ -30,7 +30,7 @@ describe('mergeMiddleware', () => {
         expect(res).toBeDefined();
         expect(originalReq.id).toStrictEqual(res.id);
         expect(originalReq.jsonrpc).toStrictEqual(res.jsonrpc);
-        expect('result' in res).toBe(true);
+        expect(hasProperty(res, 'result')).toBe(true);
         resolve();
       });
     });