fix: allow disable last remaining network on namespace (#6499)

## Explanation

This change allows the last remaining network in a namespace to be
disabled. The reason is to align with BIP-44, where account groups
shouldn’t be forced to always keep at least one active network

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## References

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## Checklist

- [ ] I've updated the test suite for new or updated code as appropriate
- [ ] I've updated documentation (JSDoc, Markdown, etc.) for new or
updated code as appropriate
- [ ] I've communicated my changes to consumers by [updating changelogs
for packages I've
changed](https://github.com/MetaMask/core/tree/main/docs/contributing.md#updating-changelogs),
highlighting breaking changes as necessary
- [ ] I've prepared draft pull requests for clients and consumer
packages to resolve any breaking changes

Author: salimtb

packages/network-enablement-controller/CHANGELOG.md

@@ -15,6 +15,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- **BREAKING:** Allow disabling the last remaining network in a namespace to align with BIP-44, where account groups shouldn't be forced to always keep at least one active network ([#6499](https://github.com/MetaMask/core/pull/6499))
 - Bump `@metamask/base-controller` from `^8.2.0` to `^8.3.0` ([#6465](https://github.com/MetaMask/core/pull/6465))
 
 ## [0.4.0]

packages/network-enablement-controller/src/NetworkEnablementController.test.ts

@@ -198,34 +198,6 @@ describe('NetworkEnablementController', () => {
     });
   });
 
-  it('subscribes to TransactionController:transactionSubmitted and enables network', async () => {
-    const { controller, messenger } = setupInitializedController();
-
-    // Initially disable Polygon network (it should not exist)
-    expect(controller.isNetworkEnabled('0x89')).toBe(false);
-
-    // Publish a transaction submitted event with Polygon chainId
-    messenger.publish('TransactionController:transactionSubmitted', {
-      transactionMeta: {
-        chainId: '0x89', // Polygon
-        networkClientId: 'polygon-network',
-        id: 'test-tx-id',
-        status: TransactionStatus.submitted,
-        time: Date.now(),
-        txParams: {
-          from: '0x123',
-          to: '0x456',
-          value: '0x0',
-        },
-      } as TransactionMeta, // Simplified structure for testing
-    });
-
-    await advanceTime({ clock, duration: 1 });
-
-    // The Polygon network should now be enabled
-    expect(controller.isNetworkEnabled('0x89')).toBe(true);
-  });
-
   it('handles TransactionController:transactionSubmitted with missing chainId gracefully', async () => {
     const { controller, messenger } = setupInitializedController();
 
@@ -1136,16 +1108,16 @@ describe('NetworkEnablementController', () => {
       });
     });
 
-    it('does not disable a Solana network using CAIP chain ID as it is the only enabled network on the namespace', () => {
+    it('does disable a Solana network using CAIP chain ID as it is the only enabled network on the namespace', () => {
       const { controller } = setupController();
 
       // Try to disable a Solana network using CAIP chain ID
       expect(() =>
         controller.disableNetwork('solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp'),
-      ).toThrow('Cannot disable the last remaining enabled network');
+      ).not.toThrow();
     });
 
-    it('prevents disabling the last active network for an EVM namespace', () => {
+    it('disables the last active network for an EVM namespace', () => {
       const { controller } = setupInitializedController();
 
       // disable all networks except one
@@ -1169,9 +1141,7 @@ describe('NetworkEnablementController', () => {
       });
 
       // Try to disable the last active network
-      expect(() => controller.disableNetwork('0x1')).toThrow(
-        'Cannot disable the last remaining enabled network',
-      );
+      expect(() => controller.disableNetwork('0x1')).not.toThrow();
     });
 
     it('handles disabling non-existent network gracefully', () => {
@@ -1424,13 +1394,11 @@ describe('NetworkEnablementController', () => {
       expect(controller.isNetworkEnabled(BtcScope.Testnet)).toBe(false);
     });
 
-    it('prevents disabling the last Bitcoin network', () => {
+    it('allows disabling the last Bitcoin network', () => {
       const { controller } = setupController();
 
       // Only Bitcoin mainnet is enabled by default in the BIP122 namespace
-      expect(() => controller.disableNetwork(BtcScope.Mainnet)).toThrow(
-        'Cannot disable the last remaining enabled network',
-      );
+      expect(() => controller.disableNetwork(BtcScope.Mainnet)).not.toThrow();
     });
 
     it('allows disabling Bitcoin mainnet when testnet is enabled', () => {
@@ -1490,7 +1458,7 @@ describe('NetworkEnablementController', () => {
       // Disable Solana network - this should fail as it's the only one in its namespace
       expect(() =>
         controller.disableNetwork('solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp'),
-      ).toThrow('Cannot disable the last remaining enabled network');
+      ).not.toThrow();
 
       // Bitcoin should still be enabled
       expect(controller.isNetworkEnabled(BtcScope.Mainnet)).toBe(true);

packages/network-enablement-controller/src/NetworkEnablementController.ts

@@ -177,18 +177,6 @@ export class NetworkEnablementController extends BaseController<
     messenger.subscribe('NetworkController:networkRemoved', ({ chainId }) => {
       this.#removeNetworkEntry(chainId);
     });
-
-    // Listen for confirmed staking transactions
-    messenger.subscribe(
-      'TransactionController:transactionSubmitted',
-      (transactionMeta) => {
-        if (transactionMeta?.transactionMeta?.chainId) {
-          this.enableNetwork(
-            transactionMeta.transactionMeta.chainId as Hex | CaipChainId,
-          );
-        }
-      },
-    );
   }
 
   /**
@@ -385,10 +373,6 @@ export class NetworkEnablementController extends BaseController<
     const derivedKeys = deriveKeys(chainId);
     const { namespace, storageKey } = derivedKeys;
 
-    if (isOnlyNetworkEnabledInNamespace(this.state, derivedKeys)) {
-      throw new Error('Cannot disable the last remaining enabled network');
-    }
-
     this.update((s) => {
       s.enabledNetworkMap[namespace][storageKey] = false;
     });