refactor: invert swap fromToken and fromChain dependency

test/data/bridge/mock-bridge-store.ts

@@ -75,6 +75,47 @@ export const MOCK_SOLANA_ACCOUNT = {
   },
 };
 
+export const MOCK_BITCOIN_ACCOUNT = {
+  type: 'bip122:p2wpkh',
+  scopes: ['bip122:000000000019d6689c085ae165831e93'],
+  id: '40b25442-ed7e-4b94-9f9f-ea8ff06d03b3',
+  address: 'bc1q2pxsagdzfdn6k6umvf9gj3eme7a27p7acym9g2',
+  options: {
+    entropySource: '01K8NT6Z7XDKEKX9MFSZ5EPFMW',
+    exportable: false,
+    entropy: {
+      type: 'mnemonic',
+      id: '01K8NT6Z7XDKEKX9MFSZ5EPFMW',
+      derivationPath: "m/84'/0'/0'",
+      groupIndex: 0,
+    },
+  },
+  methods: [
+    'signPsbt',
+    'computeFee',
+    'fillPsbt',
+    'broadcastPsbt',
+    'sendTransfer',
+    'getUtxo',
+    'listUtxos',
+    'publicDescriptor',
+    'signMessage',
+  ],
+  metadata: {
+    name: 'Snap Account 9',
+    importTime: 1763417984346,
+    keyring: {
+      type: 'Snap Keyring',
+    },
+    snap: {
+      id: 'npm:@metamask/bitcoin-wallet-snap',
+      name: 'Bitcoin',
+      enabled: true,
+    },
+    lastSelected: 1764203245474,
+  },
+};
+
 export const MOCK_EVM_ACCOUNT = {
   address: '0x0dcd5d886577d5081b0c52e242ef29e70be3e7bc',
   id: 'cf8dace4-9439-4bd4-b3a8-88c821c8fcb3',
@@ -163,6 +204,7 @@ export const createBridgeMockStore = ({
       ...(internalAccountsOverrides?.accounts ?? {}),
       [MOCK_LEDGER_ACCOUNT.id]: MOCK_LEDGER_ACCOUNT,
       [MOCK_SOLANA_ACCOUNT.id]: MOCK_SOLANA_ACCOUNT,
+      [MOCK_BITCOIN_ACCOUNT.id]: MOCK_BITCOIN_ACCOUNT,
       [MOCK_EVM_ACCOUNT.id]: MOCK_EVM_ACCOUNT,
       [MOCK_EVM_ACCOUNT_2.id]: MOCK_EVM_ACCOUNT_2,
     },
@@ -259,7 +301,11 @@ export const createBridgeMockStore = ({
                     groupIndex: 0,
                   },
                 },
-                accounts: [MOCK_EVM_ACCOUNT.id, MOCK_SOLANA_ACCOUNT.id],
+                accounts: [
+                  MOCK_EVM_ACCOUNT.id,
+                  MOCK_SOLANA_ACCOUNT.id,
+                  MOCK_BITCOIN_ACCOUNT.id,
+                ],
               },
               'entropy:01K2FF18CTTXJYD34R78X4N1N1/1': {
                 type: 'multichain-account',
@@ -325,6 +371,14 @@ export const createBridgeMockStore = ({
             name: '',
           },
         },
+        {
+          type: KeyringType.snap,
+          accounts: [MOCK_BITCOIN_ACCOUNT.address],
+          metadata: {
+            id: '01K6GQ6SXDB9GKP6CAPSRV5AJG',
+            name: '',
+          },
+        },
         {
           type: KeyringType.ledger,
           accounts: [MOCK_LEDGER_ACCOUNT.address],

ui/ducks/bridge/actions.ts

@@ -3,18 +3,12 @@ import {
   type BridgeController,
   BridgeUserAction,
   formatChainIdToCaip,
-  isNativeAddress,
-  getNativeAssetForChainId,
   type RequiredEventContextFromClient,
   UnifiedSwapBridgeEventName,
+  formatChainIdToHex,
+  isCrossChain,
 } from '@metamask/bridge-controller';
-import { type InternalAccount } from '@metamask/keyring-internal-api';
-import { type CaipChainId } from '@metamask/utils';
-import type {
-  AddNetworkFields,
-  NetworkConfiguration,
-} from '@metamask/network-controller';
-import { trace, TraceName } from '../../../shared/lib/trace';
+import { selectDefaultNetworkClientIdsByChainId } from '../../../shared/modules/selectors/networks';
 import {
   forceUpdateMetamaskState,
   setActiveNetworkWithError,
@@ -31,11 +25,12 @@ import {
   setEVMSrcNativeBalance,
 } from './bridge';
 import type { TokenPayload } from './types';
-import { isNetworkAdded, isNonEvmChain } from './utils';
+import { isNonEvmChain } from './utils';
+import { type BridgeAppState, getFromChain } from './selectors';
 
 const {
   setToChainId,
-  setFromToken,
+  setFromToken: setFromTokenAction,
   setToToken,
   setFromTokenInputValue,
   resetInputFields,
@@ -50,7 +45,6 @@ export {
   setToChainId,
   resetInputFields,
   setToToken,
-  setFromToken,
   setFromTokenInputValue,
   setDestTokenExchangeRates,
   setDestTokenUsdExchangeRates,
@@ -125,14 +119,6 @@ export const setEVMSrcTokenBalance = (
 ) => {
   return async (dispatch: MetaMaskReduxDispatch) => {
     if (token) {
-      trace({
-        name: TraceName.BridgeBalancesUpdated,
-        data: {
-          srcChainId: formatChainIdToCaip(token.chainId),
-          isNative: isNativeAddress(token.address),
-        },
-        startTime: Date.now(),
-      });
       await dispatch(
         setEVMSrcTokenBalance_({
           selectedAddress,
@@ -144,71 +130,33 @@ export const setEVMSrcTokenBalance = (
   };
 };
 
-export const setFromChain = ({
-  networkConfig,
-  selectedAccount,
-  token = null,
-}: {
-  networkConfig?:
-    | NetworkConfiguration
-    | AddNetworkFields
-    | (Omit<NetworkConfiguration, 'chainId'> & { chainId: CaipChainId });
-  selectedAccount: InternalAccount | null;
-  token?: TokenPayload['payload'];
-}) => {
-  return async (dispatch: MetaMaskReduxDispatch) => {
-    if (!networkConfig) {
-      return;
-    }
-
-    // Check for ALL non-EVM chains
-    const isNonEvm = isNonEvmChain(networkConfig.chainId);
+export const setFromToken = (token: NonNullable<TokenPayload['payload']>) => {
+  return async (
+    dispatch: MetaMaskReduxDispatch,
+    getState: () => BridgeAppState,
+  ) => {
+    const { chainId } = token;
+    const isNonEvm = isNonEvmChain(chainId);
 
+    const currentChainId = getFromChain(getState())?.chainId;
+    const shouldSetNetwork = currentChainId
+      ? isCrossChain(currentChainId, chainId)
+      : true;
     // Set the src network
-    if (isNonEvm) {
-      dispatch(setActiveNetworkWithError(networkConfig.chainId));
-    } else {
-      const networkId = isNetworkAdded(networkConfig)
-        ? networkConfig.rpcEndpoints?.[networkConfig.defaultRpcEndpointIndex]
-            ?.networkClientId
-        : null;
-      if (networkId) {
-        dispatch(setActiveNetworkWithError(networkId));
-      }
-    }
-
-    // Set the src token - if no token provided, set native token for non-EVM chains
-    if (token) {
-      dispatch(setFromToken(token));
-    } else if (isNonEvm) {
-      // Auto-select native token for non-EVM chains when switching
-      const nativeAsset = getNativeAssetForChainId(networkConfig.chainId);
-      if (nativeAsset) {
-        dispatch(
-          setFromToken({
-            ...nativeAsset,
-            chainId: networkConfig.chainId,
-          }),
-        );
+    if (shouldSetNetwork) {
+      if (isNonEvm) {
+        const caipChainId = formatChainIdToCaip(chainId);
+        dispatch(setActiveNetworkWithError(caipChainId));
+      } else {
+        const hexChainId = formatChainIdToHex(chainId);
+        const networkId =
+          selectDefaultNetworkClientIdsByChainId(getState())[hexChainId];
+        if (networkId && shouldSetNetwork) {
+          dispatch(setActiveNetworkWithError(networkId));
+        }
       }
     }
-
-    // Fetch the native balance (EVM only)
-    if (selectedAccount && !isNonEvm) {
-      trace({
-        name: TraceName.BridgeBalancesUpdated,
-        data: {
-          srcChainId: formatChainIdToCaip(networkConfig.chainId),
-          isNative: true,
-        },
-        startTime: Date.now(),
-      });
-      await dispatch(
-        setEVMSrcNativeBalance({
-          selectedAddress: selectedAccount.address,
-          chainId: networkConfig.chainId,
-        }),
-      );
-    }
+    // Set the fromToken
+    dispatch(setFromTokenAction(token));
   };
 };

ui/ducks/bridge/bridge.ts

@@ -10,10 +10,11 @@ import {
   type GenericQuoteRequest,
   type QuoteResponse,
   isBitcoinChainId,
+  isNativeAddress,
 } from '@metamask/bridge-controller';
 import { zeroAddress } from 'ethereumjs-util';
 import { fetchTxAlerts } from '../../../shared/modules/bridge-utils/security-alerts-api.util';
-import { endTrace, TraceName } from '../../../shared/lib/trace';
+import { trace, TraceName } from '../../../shared/lib/trace';
 import { SlippageValue } from '../../pages/bridge/utils/slippage-service';
 import { getTokenExchangeRate, toBridgeToken } from './utils';
 import type { BridgeState, ChainIdPayload, TokenPayload } from './types';
@@ -67,14 +68,25 @@ const getBalanceAmount = async ({
   if (isNonEvmChainId(chainId) || !selectedAddress) {
     return null;
   }
-  return (
-    await calcLatestSrcBalance(
-      global.ethereumProvider,
-      selectedAddress,
-      tokenAddress,
-      formatChainIdToHex(chainId),
-    )
-  )?.toString();
+  return await trace(
+    {
+      name: TraceName.BridgeBalancesUpdated,
+      data: {
+        srcChainId: formatChainIdToCaip(chainId),
+        isNative: isNativeAddress(tokenAddress),
+      },
+      startTime: Date.now(),
+    },
+    async () =>
+      (
+        await calcLatestSrcBalance(
+          global.ethereumProvider,
+          selectedAddress,
+          tokenAddress,
+          formatChainIdToHex(chainId),
+        )
+      )?.toString(),
+  );
 };
 
 export const setEVMSrcNativeBalance = createAsyncThunk(
@@ -216,29 +228,17 @@ const bridgeSlice = createSlice({
           ? action.meta.arg.tokenAddress === state.fromToken.address
           : true
       ) {
-        state.fromTokenBalance = action.payload?.toString() ?? null;
+        state.fromTokenBalance = action.payload ?? null;
       }
-      endTrace({
-        name: TraceName.BridgeBalancesUpdated,
-      });
     });
     builder.addCase(setEVMSrcTokenBalance.rejected, (state) => {
       state.fromTokenBalance = null;
-      endTrace({
-        name: TraceName.BridgeBalancesUpdated,
-      });
     });
     builder.addCase(setEVMSrcNativeBalance.fulfilled, (state, action) => {
-      state.fromNativeBalance = action.payload?.toString() ?? null;
-      endTrace({
-        name: TraceName.BridgeBalancesUpdated,
-      });
+      state.fromNativeBalance = action.payload ?? null;
     });
     builder.addCase(setEVMSrcNativeBalance.rejected, (state) => {
       state.fromNativeBalance = null;
-      endTrace({
-        name: TraceName.BridgeBalancesUpdated,
-      });
     });
   },
 });