update LegacyEthereumProvider; add type-integration tests

package.json

@@ -61,13 +61,15 @@
     "superstruct": "^1.0.3"
   },
   "devDependencies": {
+    "@ethersproject/providers": "^5.7.2",
     "@lavamoat/allow-scripts": "^2.3.1",
     "@lavamoat/preinstall-always-fail": "^1.0.0",
     "@metamask/auto-changelog": "^3.1.0",
     "@metamask/eslint-config": "^12.0.0",
     "@metamask/eslint-config-jest": "^12.0.0",
     "@metamask/eslint-config-nodejs": "^12.0.0",
     "@metamask/eslint-config-typescript": "^12.0.0",
+    "@metamask/eth-query": "^3.0.1",
     "@metamask/safe-event-emitter": "^3.0.0",
     "@swc/cli": "^0.1.62",
     "@swc/core": "^1.3.66",

src/json-rpc-provider-types.test-d.ts

@@ -0,0 +1,12 @@
+import { expectAssignable, expectNotAssignable } from 'tsd';
+import EthQuery from '@metamask/eth-query';
+import { Web3Provider } from '@ethersproject/providers';
+
+import type {
+  LegacyEthereumProvider
+} from '.';
+
+// Known legacy providers
+
+expectAssignable<LegacyEthereumProvider>(new EthQuery({} as any));
+expectAssignable<LegacyEthereumProvider>(new Web3Provider({} as any));

src/json-rpc-provider-types.ts

@@ -33,17 +33,46 @@ export type EIP1993Provider = SafeEventEmitter & {
  * [EIP-1193](https://eips.ethereum.org/EIPS/eip-1193). It is not compliant with
  * any Ethereum provider standard.
  */
-export type LegacyEthereumProvider = {
+export type LegacyEthereumProvider = LegacyEthersProvider | LegacyEthJsQueryProvider | LegacyWeb3Provider;
+
+type LegacyWeb3Provider = {
   /**
    * Send a provider request asynchronously.
    *
    * @param req - The request to send.
    * @param callback - A function that is called upon the success or failure of the request.
    */
-  sendAsync<Result extends Json = Json>(
+  send?<Result extends Json = Json>(
     req: Partial<JsonRpcRequest>,
     callback: SendAsyncCallback<Result>,
   ): void;
+}
+
+type LegacyEthJsQueryProvider = {
+  /**
+   * Send a provider request asynchronously. (ethjs-query)
+   *
+   * @param req - The request to send.
+   * @param callback - A function that is called upon the success or failure of the request.
+   */
+  sendAsync?<Result extends Json = Json>(
+    req: Partial<JsonRpcRequest>,
+    callback: SendAsyncCallback<Result>,
+  ): void;
+};
+
+type LegacyEthersProvider = {
+  /**
+   * Send a provider request asynchronously. (ethers v5 Web3Provider)
+   *
+   * @param method - The RPC method to call.
+   * @param params - Array with method parameters.
+   * @returns - A promise resolving with the result of the RPC call, or rejecting on failure.
+   */
+  send?<Result extends Json = Json>(
+    method: string,
+    params: any[],
+  ): Promise<Result>;
 };
 
 type SendAsyncCallback<Result extends Json> = (