fix: Gracefully handle bad responses from net_version calls to RPC endpoint when getting Provider Network State (#27509)

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## **Description**

Currently some users are seeing `Error: Cannot parse as a valid network
ID: 'undefined'` errors when connected to RPC endpoints that fail to
provide a value from `net_version` calls that can be parsed into a
decimal string. This PR makes our internally handling of this case more
flexibly by using `null` as the network version value sent to the inpage
provider when receiving an unexpected `net_version` call value.

[![Open in GitHub
Codespaces](https://github.com/codespaces/badge.svg)](https://codespaces.new/MetaMask/metamask-extension/pull/27509?quickstart=1)

## **Related issues**

Fixes: #27487

## **Manual testing steps**

1. Open extension background
2. Intercept a request for net_version (you can use a proxy like
Burpsuite) and make it return a bad value
3. There should be no error in extension background related to this
4. Open a dapp
5. Open the dapp developer console
6. Expect to see an error like `JsonRpcError: MetaMask: Disconnected
from chain. Attempting to connect.`
7. Test that `window.ethereum.request` works as expected despite this

## **Screenshots/Recordings**

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before and after of your change. -->

### **Before**

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### **After**

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## **Pre-merge author checklist**

- [ ] I've followed [MetaMask Contributor
Docs](https://github.com/MetaMask/contributor-docs) and [MetaMask
Extension Coding
Standards](https://github.com/MetaMask/metamask-extension/blob/develop/.github/guidelines/CODING_GUIDELINES.md).
- [ ] I've completed the PR template to the best of my ability
- [ ] I’ve included tests if applicable
- [ ] I’ve documented my code using [JSDoc](https://jsdoc.app/) format
if applicable
- [ ] I’ve applied the right labels on the PR (see [labeling
guidelines](https://github.com/MetaMask/metamask-extension/blob/develop/.github/guidelines/LABELING_GUIDELINES.md)).
Not required for external contributors.

## **Pre-merge reviewer checklist**

- [ ] I've manually tested the PR (e.g. pull and build branch, run the
app, test code being changed).
- [ ] I confirm that this PR addresses all acceptance criteria described
in the ticket it closes and includes the necessary testing evidence such
as recordings and or screenshots.

---------

Co-authored-by: legobeat <[email protected]>

Author: jiexi

app/scripts/metamask-controller.js

@@ -3209,7 +3209,7 @@ export default class MetamaskController extends EventEmitter {
     const { completedOnboarding } = this.onboardingController.state;
 
     let networkVersion = this.deprecatedNetworkVersions[networkClientId];
-    if (!networkVersion && completedOnboarding) {
+    if (networkVersion === undefined && completedOnboarding) {
       const ethQuery = new EthQuery(networkClient.provider);
       networkVersion = await new Promise((resolve) => {
         ethQuery.sendAsync({ method: 'net_version' }, (error, result) => {

shared/modules/network.utils.test.ts

@@ -3,6 +3,7 @@ import {
   isSafeChainId,
   isPrefixedFormattedHexString,
   isTokenDetectionEnabledForNetwork,
+  convertNetworkId,
 } from './network.utils';
 
 describe('network utils', () => {
@@ -83,4 +84,52 @@ describe('network utils', () => {
       expect(isTokenDetectionEnabledForNetwork(undefined)).toBe(false);
     });
   });
+
+  describe('convertNetworkId', () => {
+    it('returns decimal strings for postive integer number values', () => {
+      expect(convertNetworkId(0)).toStrictEqual('0');
+      expect(convertNetworkId(123)).toStrictEqual('123');
+      expect(convertNetworkId(1337)).toStrictEqual('1337');
+    });
+
+    it('returns null for negative numbers', () => {
+      expect(convertNetworkId(-1)).toStrictEqual(null);
+    });
+
+    it('returns null for non integer numbers', () => {
+      expect(convertNetworkId(0.1)).toStrictEqual(null);
+      expect(convertNetworkId(1.1)).toStrictEqual(null);
+    });
+
+    it('returns null for NaN', () => {
+      expect(convertNetworkId(Number.NaN)).toStrictEqual(null);
+    });
+
+    it('returns decimal strings for strict valid hex values', () => {
+      expect(convertNetworkId('0x0')).toStrictEqual('0');
+      expect(convertNetworkId('0x1')).toStrictEqual('1');
+      expect(convertNetworkId('0x539')).toStrictEqual('1337');
+    });
+
+    it('returns null for invalid hex values', () => {
+      expect(convertNetworkId('0xG')).toStrictEqual(null);
+      expect(convertNetworkId('0x@')).toStrictEqual(null);
+      expect(convertNetworkId('0xx1')).toStrictEqual(null);
+    });
+
+    it('returns the value as is if already a postive decimal string', () => {
+      expect(convertNetworkId('0')).toStrictEqual('0');
+      expect(convertNetworkId('1')).toStrictEqual('1');
+      expect(convertNetworkId('1337')).toStrictEqual('1337');
+    });
+
+    it('returns null for negative number strings', () => {
+      expect(convertNetworkId('-1')).toStrictEqual(null);
+    });
+
+    it('returns null for non integer number strings', () => {
+      expect(convertNetworkId('0.1')).toStrictEqual(null);
+      expect(convertNetworkId('1.1')).toStrictEqual(null);
+    });
+  });
 });

shared/modules/network.utils.ts

@@ -78,16 +78,16 @@ function isSafeInteger(value: unknown): value is number {
  * as either a number, a decimal string, or a 0x-prefixed hex string.
  *
  * @param value - The network ID to convert, in an unknown format.
- * @returns A valid network ID (as a decimal string)
- * @throws If the given value cannot be safely parsed.
+ * @returns A valid network ID (as a decimal string) or null if
+ * the given value cannot be parsed.
  */
-export function convertNetworkId(value: unknown): string {
-  if (typeof value === 'number' && !Number.isNaN(value)) {
+export function convertNetworkId(value: unknown): string | null {
+  if (typeof value === 'number' && Number.isInteger(value) && value >= 0) {
     return `${value}`;
   } else if (isStrictHexString(value)) {
     return `${convertHexToDecimal(value)}`;
   } else if (typeof value === 'string' && /^\d+$/u.test(value)) {
     return value;
   }
-  throw new Error(`Cannot parse as a valid network ID: '${value}'`);
+  return null;
 }