fix _handleChainChanged in MetaMaskInpageProvider to handle networkVe…

…rsion (#171)

fix _handleChainChanged in MetaMaskInpageProvider to handle networkVersion

Co-authored-by: Erik Marks <25517051+rekmarks@users.noreply.github.com>

src/BaseProvider.rpc.test.ts

@@ -309,4 +309,25 @@ describe('BaseProvider: RPC', () => {
       });
     });
   });
+  describe('provider events', () => {
+    it('calls chainChanged when it chainId changes ', async () => {
+      const mockStream = new MockDuplexStream();
+      const baseProvider = new BaseProvider(mockStream);
+      (baseProvider as any)._state.initialized = true;
+      await new Promise((resolve) => {
+        baseProvider.on('chainChanged', (changed) => {
+          expect(changed).toBeDefined();
+          resolve(undefined);
+        });
+        mockStream.push({
+          name: 'metamask-provider',
+          data: {
+            jsonrpc: '2.0',
+            method: 'metamask_chainChanged',
+            params: { chainId: '0x1', networkVersion: '0x1' },
+          },
+        });
+      });
+    });
+  });
 });

src/MetaMaskInpageProvider.rpc.test.ts

@@ -636,4 +636,46 @@ describe('MetaMaskInpageProvider: RPC', () => {
       );
     });
   });
+
+  describe('provider events', () => {
+    it('calls chainChanged when it chainId changes ', async () => {
+      const mockStream = new MockDuplexStream();
+      const inpageProvider = new MetaMaskInpageProvider(mockStream);
+      (inpageProvider as any)._state.initialized = true;
+      await new Promise((resolve) => {
+        inpageProvider.on('chainChanged', (changed) => {
+          expect(changed).toBe('0x1');
+          resolve(undefined);
+        });
+        mockStream.push({
+          name: 'metamask-provider',
+          data: {
+            jsonrpc: '2.0',
+            method: 'metamask_chainChanged',
+            params: { chainId: '0x1', networkVersion: '0x1' },
+          },
+        });
+      });
+    });
+
+    it('calls networkChanged when it networkVersion changes ', async () => {
+      const mockStream = new MockDuplexStream();
+      const inpageProvider = new MetaMaskInpageProvider(mockStream);
+      (inpageProvider as any)._state.initialized = true;
+      await new Promise((resolve) => {
+        inpageProvider.on('networkChanged', (changed) => {
+          expect(changed).toBe('0x1');
+          resolve(undefined);
+        });
+        mockStream.push({
+          name: 'metamask-provider',
+          data: {
+            jsonrpc: '2.0',
+            method: 'metamask_chainChanged',
+            params: { chainId: '0x1', networkVersion: '0x1' },
+          },
+        });
+      });
+    });
+  });
 });

src/MetaMaskInpageProvider.ts

@@ -395,4 +395,34 @@ export default class MetaMaskInpageProvider extends BaseProvider {
       },
     );
   }
+
+  /**
+   * Upon receipt of a new chainId and networkVersion, emits corresponding
+   * events and sets relevant public state.
+   * Does nothing if neither the chainId nor the networkVersion are different
+   * from existing values.
+   *
+   * @emits MetamaskInpageProvider#chainChanged
+   * @emits MetamaskInpageProvider#networkChanged
+   * @param networkInfo - An object with network info.
+   * @param networkInfo.chainId - The latest chain ID.
+   * @param networkInfo.networkVersion - The latest network ID.
+   */
+  protected _handleChainChanged({
+    chainId,
+    networkVersion,
+  }: { chainId?: string; networkVersion?: string } = {}) {
+    super._handleChainChanged({ chainId, networkVersion });
+
+    if (
+      networkVersion &&
+      networkVersion !== 'loading' &&
+      networkVersion !== this.networkVersion
+    ) {
+      this.networkVersion = networkVersion;
+      if (this._state.initialized) {
+        this.emit('networkChanged', this.networkVersion);
+      }
+    }
+  }
 }