refactor: Add context generic to PollingBlockTracker

Author: rekmarks

packages/eth-block-tracker/src/PollingBlockTracker.ts

@@ -1,4 +1,8 @@
 import type { InternalProvider } from '@metamask/eth-json-rpc-provider';
+import type {
+  ContextConstraint,
+  MiddlewareContext,
+} from '@metamask/json-rpc-engine/v2';
 import SafeEventEmitter from '@metamask/safe-event-emitter';
 import {
   createDeferredPromise,
@@ -17,8 +21,10 @@ const sec = 1000;
 
 const blockTrackerEvents: (string | symbol)[] = ['sync', 'latest'];
 
-export type PollingBlockTrackerOptions = {
-  provider?: InternalProvider;
+export type PollingBlockTrackerOptions<
+  Context extends ContextConstraint = MiddlewareContext,
+> = {
+  provider?: InternalProvider<Context>;
   pollingInterval?: number;
   retryTimeout?: number;
   keepEventLoopActive?: boolean;
@@ -33,7 +39,9 @@ type ExtendedJsonRpcRequest = {
 
 type InternalListener = (value: string) => void;
 
-export class PollingBlockTracker
+export class PollingBlockTracker<
+    Context extends ContextConstraint = MiddlewareContext,
+  >
   extends SafeEventEmitter
   implements BlockTracker
 {
@@ -49,7 +57,7 @@ export class PollingBlockTracker
 
   private _pollingTimeout?: ReturnType<typeof setTimeout>;
 
-  private readonly _provider: InternalProvider;
+  private readonly _provider: InternalProvider<Context>;
 
   private readonly _pollingInterval: number;
 
@@ -65,7 +73,7 @@ export class PollingBlockTracker
 
   #pendingFetch?: Omit<DeferredPromise<string>, 'resolve'>;
 
-  constructor(opts: PollingBlockTrackerOptions = {}) {
+  constructor(opts: PollingBlockTrackerOptions<Context> = {}) {
     // parse + validate args
     if (!opts.provider) {
       throw new Error('PollingBlockTracker - no provider specified.');

packages/network-controller/tests/NetworkController.test.ts

@@ -13,7 +13,6 @@ import {
   NetworkType,
   toHex,
 } from '@metamask/controller-utils';
-import type { InternalProvider } from '@metamask/eth-json-rpc-provider';
 import { rpcErrors } from '@metamask/rpc-errors';
 import type { Hex } from '@metamask/utils';
 import assert from 'assert';
@@ -16641,7 +16640,7 @@ function buildFakeClient(
     },
     provider,
     blockTracker: new FakeBlockTracker({
-      provider: provider as unknown as InternalProvider,
+      provider,
     }),
     destroy: () => {
       // do nothing

tests/fake-block-tracker.ts

@@ -1,14 +1,20 @@
 import { PollingBlockTracker } from '@metamask/eth-block-tracker';
 import type { InternalProvider } from '@metamask/eth-json-rpc-provider';
+import type {
+  ContextConstraint,
+  MiddlewareContext,
+} from '@metamask/json-rpc-engine/v2';
 
 /**
  * Acts like a PollingBlockTracker, but doesn't start the polling loop or
  * make any requests.
  */
-export class FakeBlockTracker extends PollingBlockTracker {
+export class FakeBlockTracker<
+  Context extends ContextConstraint = MiddlewareContext,
+> extends PollingBlockTracker<Context> {
   #latestBlockNumber = '0x0';
 
-  constructor({ provider }: { provider: InternalProvider }) {
+  constructor({ provider }: { provider: InternalProvider<Context> }) {
     super({
       provider,
     });