fix(eth-block-tracker): promote @metamask/json-rpc-engine to a production dependency

packages/eth-block-tracker/CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Promote `@metamask/json-rpc-engine` from a dev dependency to a production dependency, so the `ContextConstraint` and `MiddlewareContext` types it contributes to `PollingBlockTracker`'s public declaration files resolve for downstream consumers ([#6864](https://github.com/MetaMask/core/issues/6864))
 - Deduplicate concurrent `checkForLatestBlock()` calls so they share a single ongoing request and resolve to the same promise, instead of each issuing its own `eth_blockNumber` request ([#7905](https://github.com/MetaMask/core/pull/7905))
 
 ## [15.0.1]

packages/eth-block-tracker/package.json

@@ -56,13 +56,13 @@
   },
   "dependencies": {
     "@metamask/eth-json-rpc-provider": "^6.0.1",
+    "@metamask/json-rpc-engine": "^10.5.0",
     "@metamask/safe-event-emitter": "^3.0.0",
     "@metamask/utils": "^11.11.0",
     "json-rpc-random-id": "^1.0.1"
   },
   "devDependencies": {
     "@metamask/auto-changelog": "^6.1.0",
-    "@metamask/json-rpc-engine": "^10.5.0",
     "@ts-bridge/cli": "^0.6.4",
     "@types/jest": "^30.0.0",
     "@types/json-rpc-random-id": "^1.0.1",

packages/eth-block-tracker/src/dependencies.test.ts

@@ -0,0 +1,22 @@
+import { readFileSync } from 'fs';
+import { resolve } from 'path';
+
+describe('@metamask/eth-block-tracker package manifest', () => {
+  it('declares @metamask/json-rpc-engine as a production dependency', () => {
+    // `PollingBlockTracker.ts` imports the `ContextConstraint` and
+    // `MiddlewareContext` types from `@metamask/json-rpc-engine/v2` with a
+    // type-only import. Those types leak into the published declaration files
+    // through `PollingBlockTrackerOptions` and the `PollingBlockTracker` class
+    // generic, so consumers need `@metamask/json-rpc-engine` resolvable when
+    // type-checking against this package. It must therefore be a production
+    // dependency rather than only a devDependency.
+    //
+    // Regression test for https://github.com/MetaMask/core/issues/6864
+    const packageJsonPath = resolve(__dirname, '..', 'package.json');
+    const { dependencies } = JSON.parse(
+      readFileSync(packageJsonPath, 'utf8'),
+    ) as { dependencies: Record<string, string> };
+
+    expect(dependencies['@metamask/json-rpc-engine']).toBeDefined();
+  });
+});