feat(snaps): Add support for custom network per Snap

app/scripts/lib/rpc-method-middleware/handlers/switch-ethereum-chain.js

@@ -1,4 +1,5 @@
 import { providerErrors } from '@metamask/rpc-errors';
+import { isSnapId } from '@metamask/snaps-utils';
 
 import { MESSAGE_TYPE } from '../../../../../shared/constants/app';
 import {
@@ -78,6 +79,7 @@ async function switchEthereumChainHandler(
   return switchChain(res, end, chainId, networkClientIdToSwitchTo, {
     origin,
     isSwitchFlow: true,
+    autoApprove: isSnapId(origin),
     setActiveNetwork,
     getCaveat,
     requestPermittedChainsPermissionIncrementalForOrigin,

app/scripts/lib/rpc-method-middleware/handlers/switch-ethereum-chain.test.js

@@ -168,6 +168,7 @@ describe('switchEthereumChainHandler', () => {
       '0xdeadbeef',
       'mainnet',
       {
+        autoApprove: false,
         setActiveNetwork: mocks.setActiveNetwork,
         fromNetworkConfiguration: {
           chainId: '0xe708',
@@ -198,4 +199,31 @@ describe('switchEthereumChainHandler', () => {
       },
     );
   });
+
+  it('calls `switchChain` with `autoApprove: true` if the origin is a Snap', async () => {
+    const { mocks } = createMockedHandler();
+
+    const switchEthereumChainHandler = switchEthereumChain.implementation;
+    await switchEthereumChainHandler(
+      {
+        origin: 'npm:foo-snap',
+        params: [{ chainId: CHAIN_IDS.MAINNET }],
+      },
+      {},
+      jest.fn(),
+      jest.fn(),
+      mocks,
+    );
+
+    expect(EthChainUtils.switchChain).toHaveBeenCalledTimes(1);
+    expect(EthChainUtils.switchChain).toHaveBeenCalledWith(
+      {},
+      expect.any(Function),
+      CHAIN_IDS.MAINNET,
+      NETWORK_TYPES.MAINNET,
+      expect.objectContaining({
+        autoApprove: true,
+      }),
+    );
+  });
 });

app/scripts/metamask-controller.js

@@ -136,8 +136,6 @@ import {
   TransactionType,
 } from '@metamask/transaction-controller';
 
-import { isSnapId } from '@metamask/snaps-utils';
-
 import { Interface } from '@ethersproject/abi';
 import { abiERC1155, abiERC721 } from '@metamask/metamask-eth-abis';
 import { isEvmAccountType } from '@metamask/keyring-api';
@@ -5533,12 +5531,6 @@ export default class MetamaskController extends EventEmitter {
     autoApprove,
     metadata,
   }) {
-    if (isSnapId(origin)) {
-      throw new Error(
-        `Cannot request permittedChains permission for Snaps with origin "${origin}"`,
-      );
-    }
-
     const caveatValueWithChains = setPermittedEthChainIds(
       {
         requiredScopes: {},
@@ -5589,11 +5581,11 @@ export default class MetamaskController extends EventEmitter {
    * Requests user approval for the CAIP-25 permission for the specified origin
    * and returns a granted permissions object.
    *
-   * @param {string} origin - The origin to request approval for.
+   * @param {string} _origin - The origin to request approval for.
    * @param requestedPermissions - The legacy permissions to request approval for.
    * @returns the approved permissions object.
    */
-  getCaip25PermissionFromLegacyPermissions(origin, requestedPermissions = {}) {
+  getCaip25PermissionFromLegacyPermissions(_origin, requestedPermissions = {}) {
     const permissions = pick(requestedPermissions, [
       RestrictedMethods.eth_accounts,
       PermissionNames.permittedChains,
@@ -5607,10 +5599,6 @@ export default class MetamaskController extends EventEmitter {
       permissions[PermissionNames.permittedChains] = {};
     }
 
-    if (isSnapId(origin)) {
-      delete permissions[PermissionNames.permittedChains];
-    }
-
     const requestedAccounts =
       permissions[RestrictedMethods.eth_accounts]?.caveats?.find(
         (caveat) => caveat.type === CaveatTypes.restrictReturnedAccounts,
@@ -5633,7 +5621,7 @@ export default class MetamaskController extends EventEmitter {
 
     const caveatValueWithChains = setPermittedEthChainIds(
       newCaveatValue,
-      isSnapId(origin) ? [] : requestedChains,
+      requestedChains,
     );
 
     const caveatValueWithAccountsAndChains = setEthAccounts(

app/scripts/metamask-controller.test.js

@@ -1243,90 +1243,6 @@ describe('MetaMaskController', () => {
         );
       });
 
-      it('returns approval from the PermissionsController for only eth_accounts when only permittedChains is specified in params and origin is snapId', async () => {
-        const permissions =
-          await metamaskController.getCaip25PermissionFromLegacyPermissions(
-            'npm:snap',
-            {
-              [PermissionNames.permittedChains]: {
-                caveats: [
-                  {
-                    type: CaveatTypes.restrictNetworkSwitching,
-                    value: ['0x64'],
-                  },
-                ],
-              },
-            },
-          );
-
-        expect(permissions).toStrictEqual(
-          expect.objectContaining({
-            [Caip25EndowmentPermissionName]: {
-              caveats: [
-                {
-                  type: Caip25CaveatType,
-                  value: {
-                    requiredScopes: {},
-                    optionalScopes: {
-                      'wallet:eip155': {
-                        accounts: [],
-                      },
-                    },
-                    isMultichainOrigin: false,
-                  },
-                },
-              ],
-            },
-          }),
-        );
-      });
-
-      it('returns approval from the PermissionsController for only eth_accounts when both eth_accounts and permittedChains are specified in params and origin is snapId', async () => {
-        const permissions =
-          await metamaskController.getCaip25PermissionFromLegacyPermissions(
-            'npm:snap',
-            {
-              [PermissionNames.eth_accounts]: {
-                caveats: [
-                  {
-                    type: CaveatTypes.restrictReturnedAccounts,
-                    value: ['foo'],
-                  },
-                ],
-              },
-              [PermissionNames.permittedChains]: {
-                caveats: [
-                  {
-                    type: CaveatTypes.restrictNetworkSwitching,
-                    value: ['0x64'],
-                  },
-                ],
-              },
-            },
-          );
-
-        expect(permissions).toStrictEqual(
-          expect.objectContaining({
-            [Caip25EndowmentPermissionName]: {
-              caveats: [
-                {
-                  type: Caip25CaveatType,
-                  value: {
-                    requiredScopes: {},
-                    optionalScopes: {
-                      'wallet:eip155': {
-                        accounts: ['wallet:eip155:foo'],
-                      },
-                    },
-                    isMultichainOrigin: false,
-                  },
-                },
-              ],
-            },
-          }),
-        );
-      });
-
       it('returns CAIP-25 approval with accounts and chainIds specified from `eth_accounts` and `endowment:permittedChains` permissions caveats, and isMultichainOrigin: false if origin is not snapId', async () => {
         const permissions =
           await metamaskController.getCaip25PermissionFromLegacyPermissions(
@@ -1378,54 +1294,6 @@ describe('MetaMaskController', () => {
           }),
         );
       });
-
-      it('returns CAIP-25 approval with approved accounts for the `wallet:eip155` scope (and no approved chainIds) with isMultichainOrigin: false if origin is snapId', async () => {
-        const origin = 'npm:snap';
-
-        const permissions =
-          await metamaskController.getCaip25PermissionFromLegacyPermissions(
-            origin,
-            {
-              [RestrictedEthMethods.eth_accounts]: {
-                caveats: [
-                  {
-                    type: 'restrictReturnedAccounts',
-                    value: ['0xdeadbeef'],
-                  },
-                ],
-              },
-              [EndowmentTypes.permittedChains]: {
-                caveats: [
-                  {
-                    type: 'restrictNetworkSwitching',
-                    value: ['0x1', '0x5'],
-                  },
-                ],
-              },
-            },
-          );
-
-        expect(permissions).toStrictEqual(
-          expect.objectContaining({
-            [Caip25EndowmentPermissionName]: {
-              caveats: [
-                {
-                  type: Caip25CaveatType,
-                  value: {
-                    requiredScopes: {},
-                    optionalScopes: {
-                      'wallet:eip155': {
-                        accounts: ['wallet:eip155:0xdeadbeef'],
-                      },
-                    },
-                    isMultichainOrigin: false,
-                  },
-                },
-              ],
-            },
-          }),
-        );
-      });
     });
 
     describe('requestApprovalPermittedChainsPermission', () => {
@@ -1485,19 +1353,6 @@ describe('MetaMaskController', () => {
     });
 
     describe('requestPermittedChainsPermissionIncremental', () => {
-      it('throws if the origin is snapId', async () => {
-        await expect(() =>
-          metamaskController.requestPermittedChainsPermissionIncremental({
-            origin: 'npm:snap',
-            chainId: '0x1',
-          }),
-        ).rejects.toThrow(
-          new Error(
-            'Cannot request permittedChains permission for Snaps with origin "npm:snap"',
-          ),
-        );
-      });
-
       it('requests permittedChains approval if autoApprove: false', async () => {
         const expectedCaip25Permission = {
           [Caip25EndowmentPermissionName]: {