test(e2e): cross-chain swaps

.github/workflows/e2e-pw-nightly.yml

@@ -18,6 +18,7 @@ jobs:
     env:
       INTEGRATION_TEST_PRIVATE_KEY: ${{ secrets.INTEGRATION_TEST_PRIVATE_KEY }}
       REACT_APP_NETWORK_URL_11155111: ${{ secrets.REACT_APP_NETWORK_URL_11155111 }}
+      REACT_APP_NETWORK_URL_1: ${{ secrets.REACT_APP_NETWORK_URL_1 }}
       E2E_PW_MM_SEED: ${{ secrets.E2E_PW_MM_SEED }}
       CI: 'true'
     steps:

.github/workflows/e2e-pw-smoke.yml

@@ -22,6 +22,7 @@ jobs:
     env:
       INTEGRATION_TEST_PRIVATE_KEY: ${{ secrets.INTEGRATION_TEST_PRIVATE_KEY }}
       REACT_APP_NETWORK_URL_11155111: ${{ secrets.REACT_APP_NETWORK_URL_11155111 }}
+      REACT_APP_NETWORK_URL_1: ${{ secrets.REACT_APP_NETWORK_URL_1 }}
       E2E_PW_MM_SEED: ${{ secrets.E2E_PW_MM_SEED }}
       CI: 'true'
     steps:

apps/cowswap-e2e-tests/.env.example

@@ -1,2 +1,3 @@
 REACT_APP_NETWORK_URL_11155111=https://ethereum-sepolia-rpc.publicnode.com
+REACT_APP_NETWORK_URL_1=https://ethereum-rpc.publicnode.com
 INTEGRATION_TEST_PRIVATE_KEY=0x000000

apps/cowswap-e2e-tests/AGENTS.md

@@ -1,7 +1,7 @@
 ---
 author: agents
 status: normative
-last_reviewed: 2026-08-04
+last_reviewed: 2026-08-11
 source_of_truth_scope: cowswap-e2e-tests app-specific conventions, mocks, and debugging notes
 ---
 
@@ -125,6 +125,100 @@ behavior, only to call its methods). Sub-mocks:
   `REACT_APP_NETWORK_URL_11155111` in its own environment (it's a separate process from the test runner,
   which has it), or a transient DNS blip in the sandbox.
 
+## Cross-chain bridging (`cross-chain-swaps.spec.ts`)
+
+- **LaunchDarkly can't be mocked via HTTP here.** With no `REACT_APP_LAUNCH_DARKLY_KEY` configured,
+  the real LD SDK never even attempts flag-evaluation polling (only a `/sdk/goals/` call fires, never
+  `/sdk/evalx/...`), so route-mocking its API is a dead end. Instead `useFeatureFlags()`
+  (`libs/common-hooks/src/useFeatureFlags.ts`) reads `window.__COWSWAP_E2E_FEATURE_FLAGS__` directly and
+  merges it over the real (permanently unresolved) flags; `mocks/launchDarkly.ts` sets that window
+  property via `context.addInitScript`, and `mocks.launchDarkly.setFlag(key, value)` is how a spec turns
+  on `isBungeeBridgeProviderEnabled` / `isNearIntentsBridgeProviderEnabled` / `isSolBridgeEnabled` /
+  `isBtcBridgeEnabled`, etc. Bungee alone doesn't need this — it's added to the provider set
+  unconditionally at module load in `tradingSdk/bridgingSdk.ts`.
+- **Near Intents' attestation is a real ECDSA signature check and cannot be forged.**
+  `recoverDepositAddress` verifies the quote/attestation pair against Near's real attestor key — a
+  captured fixture pair only satisfies it if replayed byte-for-byte for the exact route it was captured
+  for. `bridgingSdk.ts` patches `nearIntentsBridgeProvider.recoverDepositAddress` to a no-op success,
+  gated behind the existing `window.__COWSWAP_E2E__` flag — a production-source-file edit, but scoped to
+  e2e only. Consequently the Near fixture (`mocks/bridge/fixtures/near-quote.json` /
+  `near-attestation.json`) can only be served verbatim for the one route it was recorded against
+  (Mainnet USDC → Base USDC) — don't edit its numbers.
+- **`BridgingSdk.getBestQuote()` always fetches a *regular* CoW quote first** (swap leg: sell token →
+  intermediate token) and feeds that quote's `buyAmount` in as the amount the bridge provider itself
+  quotes. The default `/quote` fixture's scaling is tuned for a same-decimals WETH:testUSDC pair and
+  produces nonsense for any other pair — always pin the swap leg with `mockFixedRateQuote` for a
+  cross-chain test. **When sell and intermediate-buy token decimals differ (e.g. native ETH's 18dec sell
+  → a 6dec USDC intermediate), `mockFixedRateQuote`'s plain `sellAmount * numerator / denominator` is
+  decimals-*agnostic* and silently produces an amount ~12 orders of magnitude too large** (surfaces as
+  an absurd `"for at least 99.339B USDC"` in the confirm modal). Override `quote` a second time after
+  `mockFixedRateQuote` with a manually decimals-adjusted ratio in that case (see `[CC-13]`).
+- **The app's own real-RPC traffic for a given chain does *not* reliably go through
+  `REACT_APP_NETWORK_URL_<chainId>`.** That env var only backs this suite's own wallet-side
+  dispatch/proxy (`walletEngine.ts` → `rpcProxy.ts`) and the handful of reads `mockEthFlowTransaction`/
+  `mockSocketVerifier` intercept by that exact URL (tx receipts, native-balance multicalls). Plenty of
+  other calls the *app itself* makes — Bungee's on-chain SocketVerifier check, `eth_estimateGas` before
+  every `eth_sendTransaction` — go straight to whichever of the app's own hardcoded providers it picks
+  (Infura, the WalletConnect RPC relay, publicnode, ...), unpredictable and outside this env var's
+  control. The only reliable way to intercept these is host-agnostic: `context.route('**/*', ...)`,
+  decode the JSON-RPC body, and match by `method` (see `mockSocketVerifier.ts` and
+  `mockEthEstimateGas` in `mockEthFlowTransaction.ts`), never by URL.
+- **A real native-ETH sell (`[CC-13]`, eth-flow) needs `eth_estimateGas` stubbed too, not just
+  `eth_sendTransaction`.** Left unmocked, gas estimation is a real simulation against the wallet's real
+  on-chain balance — zero on Mainnet, since this is a shared test key with no real funds (never fund it;
+  Sepolia's equivalent test works only because that address genuinely holds real, free Sepolia ETH) — and
+  fails with a genuine "exceeds the balance of the account" error before the stubbed send is ever
+  reached.
+- **`mockOrderPosting` doesn't work for eth-flow orders** — there's no `postOrder` call to hook (the uid
+  is computed client-side before anything is sent on-chain). Override `order`/`orderStatus` manually
+  instead (mirrors `[MO-11]`). One extra step specific to *bridging* eth-flow orders:
+  `useSwapAndBridgeContext` resolves the bridge provider from `order.apiAdditionalInfo.fullAppData`
+  (`bridgingSdk.getProviderFromAppData`) — without it, `bridgingStatus` never resolves and the progress
+  modal sticks on "Executing" forever regardless of what `order`/`orderStatus` say. Since an eth-flow tx
+  only carries the app-data *hash* on-chain (no room for the full JSON in a `bytes32`), capture the real
+  document via a `putAppData` override (`(req.body as { fullAppData: string }).fullAppData`) and thread
+  it into the `order` override's own `fullAppData` field.
+- **"Expected to receive" and "Min. to receive" are computed completely differently for a bridge leg,
+  and only one of them gets rescaled to match the swap leg.** `useEstimatedBridgeBuyAmount` rescales the
+  swap leg's real output through the bridge quote's own before-fee ratio, so form `Receive (incl. fees)`,
+  the *bridge* stop's `Expected to receive`, and (for Bungee, whose mock scales proportionally) roughly
+  the swap stop's own figure all end up self-consistent. `Min. to receive` at the bridge stop is **not**
+  rescaled — it's the bridge SDK quote's raw `amountsAndCosts.afterSlippage.buyAmount`, carrying that
+  provider's own real routeFee/slippage. Don't assert equality between a swap leg's and a bridge leg's
+  `Min. to receive` — assert presence instead. For Near Intents specifically, both the quote's `sellAmount`
+  and `buyAmount` come from the same static signed fixture, so its bridge-stop `Min. to receive` is an
+  absolute number from that fixture, unrelated to whatever amount the test actually trades.
+- **Solana availability needs two independent flags, Bitcoin needs only one.** `isSolBridgeEnabled` /
+  `isBtcBridgeEnabled` (the LD-bypass flags above) gate chain *availability* in
+  `useSupportedTargetChains`, but Solana additionally needs `IS_SOLANA_ENABLED` — a plain
+  `localStorage.getItem('IS_SOLANA_ENABLED')` check (`libs/common-const/src/featureFlags.ts`), a
+  completely different mechanism — for `CHAIN_INFO` to have a Solana entry to look up at all. Set it via
+  `context.addInitScript(() => localStorage.setItem('IS_SOLANA_ENABLED', '1'))` before navigating.
+- **Near Intents' real dest-tokens fixture has no usable exact-"BTC" entry.** Its one `blockchain: "btc"`
+  token with `symbol: "BTC"` (`nep141:btc.omft.near`) is on the SDK's own hardcoded deprecated-asset-id
+  list and gets filtered out client-side; the only Bitcoin-chain token that survives is
+  `symbol: "BTC(OMNI)"`. Search/pick `BTC(OMNI)`, not `BTC`.
+- **Validation-blocking button states can render with no `id` at all.** `TradeFormButtons` only gives
+  `#do-trade-button` to the "no validation errors" case; a function-component validation state (e.g.
+  `RecipientNotSet`, `RecipientNotConfirmed` in `tradeButtonsMap.tsx`) renders its own
+  `TradeFormBlankButton` with no `id` prop. Match those by role/text
+  (`page.getByRole('button', { name: /.../i })`), not by a `#do-trade-button`/`swapButton` locator.
+- **A controlled confirmation checkbox can lose a click under load.** `recipientConfirmationCheckbox`
+  (`#receiver-confirmation`) is driven by recipient-validation state that can still be settling right
+  after typing an address; a still-in-flight debounce can reset `confirmed` back to `false` immediately
+  after Playwright's `.check()` lands, surfacing as "Clicking the checkbox did not change its state" —
+  reproduces reliably only under concurrent test load (multiple workers), not in isolation. Retry via
+  `expect.poll(async () => { await checkbox.check(); return checkbox.isChecked() }).toBe(true)` instead
+  of a single `.check()`.
+- The app's HashRouter makes `page.goto()` to a new `#/...` route a same-document navigation —
+  `bridgingSdk`'s available-provider set is a page-lifetime singleton seeded once at module load, so a
+  test that switches providers mid-test (`mocks.launchDarkly.setFlag` again) needs an actual
+  `page.reload()` after the new hash is already in the address bar for the switch to take effect.
+- The Bungee quote fixture's `output.amount` is a single captured absolute number, unrelated to whatever
+  amount a given test's sell leg actually produces — `mocks/bungee.ts`'s `/quote` handler scales every
+  amount field (and their USD counterparts) proportionally to the live `inputAmount` query param to keep
+  the fixture's own input:output ratio (and therefore price impact) realistic for any sell amount.
+
 ## Known issues (discovered this session, unresolved)
 
 - **`mocks.balances.set()` called after the app already has an open SSE connection (e.g. from inside a

apps/cowswap-e2e-tests/src/fixtures/shared.ts

@@ -2,13 +2,15 @@ import { createRpcProxyHandle, type RpcProxyHandle } from './rpcProxy'
 
 import { installAllowances, type AllowancesMock } from '../mocks/allowances'
 import { installBalances, type BalancesMock } from '../mocks/balances'
+import { installBungee, type BungeeMock } from '../mocks/bungee'
 import { installCowProtocolApi, type CowProtocolApiMock } from '../mocks/cowProtocolApi'
 import { installEthBlockNumber } from '../mocks/ethBlockNumber'
 import { installEthEstimateGas } from '../mocks/ethEstimateGas'
 import { installEthGetCode, type EthGetCodeMock } from '../mocks/ethGetCode'
 import { installEthGetTransactionCount } from '../mocks/ethGetTransactionCount'
 import { installLaunchDarkly, type LaunchDarklyMock } from '../mocks/launchDarkly'
 import { installMulticall3 } from '../mocks/multicall3'
+import { installNearIntents, type NearIntentsMock } from '../mocks/nearIntents'
 import { installSafeSdk, type SafeSdkMock } from '../mocks/safeSdk'
 import { installTokenLists, type TokenListsMock } from '../mocks/tokenLists'
 import { installUsdPrices, type UsdPricesMock } from '../mocks/usdPrices'
@@ -44,6 +46,8 @@ export interface SharedFixtures {
     ethGetCode: EthGetCodeMock
     tokenLists: TokenListsMock
     safeSdk: SafeSdkMock
+    bungee: BungeeMock
+    nearIntents: NearIntentsMock
     launchDarkly: LaunchDarklyMock
     usdPrices: UsdPricesMock
   }
@@ -123,6 +127,8 @@ export const sharedFixtures: Fixtures<
       installMulticall3(context, { allowances })
       const tokenLists = installTokenLists(context)
       const safeSdk = installSafeSdk(context)
+      const bungee = installBungee(context)
+      const nearIntents = installNearIntents(context)
       const launchDarkly = installLaunchDarkly(context)
       const usdPrices = installUsdPrices(context)
 
@@ -133,12 +139,16 @@ export const sharedFixtures: Fixtures<
         ethGetCode,
         tokenLists,
         safeSdk,
+        bungee,
+        nearIntents,
         launchDarkly,
         usdPrices,
       })
 
       ethGetCode.reset()
       tokenLists.reset()
+      bungee.reset()
+      nearIntents.reset()
       await launchDarkly.reset()
       usdPrices.reset()
       await safeSdk.disable()

apps/cowswap-e2e-tests/src/mocks/bridge/fixtures/bungee-dest-tokens.json

@@ -0,0 +1,79 @@
+{
+  "success": true,
+  "statusCode": 200,
+  "result": [
+    {
+      "chainId": 8453,
+      "address": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
+      "name": "USDC",
+      "symbol": "USDC",
+      "decimals": 6,
+      "logoURI": "https://assets.coingecko.com/coins/images/6319/large/USDC.png?1769615602",
+      "icon": "https://assets.coingecko.com/coins/images/6319/large/USDC.png?1769615602"
+    },
+    {
+      "chainId": 8453,
+      "address": "0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee",
+      "name": "Ether",
+      "symbol": "ETH",
+      "decimals": 18,
+      "logoURI": "https://media.socket.tech/networks/ethereum.svg",
+      "icon": "https://media.socket.tech/networks/ethereum.svg"
+    },
+    {
+      "chainId": 8453,
+      "address": "0x4e107a0000db66f0e9fd2039288bf811dd1f9c74",
+      "name": "Velora",
+      "symbol": "VLR",
+      "decimals": 18,
+      "logoURI": "https://assets.coingecko.com/coins/images/55593/large/PNG_Round.png?1746809175",
+      "icon": "https://assets.coingecko.com/coins/images/55593/large/PNG_Round.png?1746809175"
+    },
+    {
+      "chainId": 8453,
+      "address": "0xd652c5425aea2afd5fb142e120fecf79e18fafc3",
+      "name": "PoolTogether",
+      "symbol": "POOL",
+      "decimals": 18,
+      "logoURI": "https://assets.coingecko.com/coins/images/14003/large/PoolTogether.png?1696513732",
+      "icon": "https://assets.coingecko.com/coins/images/14003/large/PoolTogether.png?1696513732"
+    },
+    {
+      "chainId": 8453,
+      "address": "0xfde4c96c8593536e31f229ea8f37b2ada2699bb2",
+      "name": "L2 Standard Bridged USDT  Base ",
+      "symbol": "USDT",
+      "decimals": 6,
+      "logoURI": "https://assets.coingecko.com/coins/images/39963/large/usdt.png?1724952731",
+      "icon": "https://assets.coingecko.com/coins/images/39963/large/usdt.png?1724952731"
+    },
+    {
+      "chainId": 8453,
+      "address": "0xd9aaec86b65d86f6a7b5b1b0c42ffa531710b6ca",
+      "name": "Bridged USDC  Base ",
+      "symbol": "USDBC",
+      "decimals": 6,
+      "logoURI": "https://assets.coingecko.com/coins/images/31164/large/baseusdc.jpg?1696529993",
+      "icon": "https://assets.coingecko.com/coins/images/31164/large/baseusdc.jpg?1696529993"
+    },
+    {
+      "chainId": 8453,
+      "address": "0x50c5725949a6f0c72e6c4a641f24049a917db0cb",
+      "name": "L2 Standard Bridged DAI  Base ",
+      "symbol": "DAI",
+      "decimals": 18,
+      "logoURI": "https://assets.coingecko.com/coins/images/39807/large/dai.png?1724126571",
+      "icon": "https://assets.coingecko.com/coins/images/39807/large/dai.png?1724126571"
+    },
+    {
+      "chainId": 8453,
+      "address": "0x4158734d47fc9692176b5085e0f52ee0da5d47f1",
+      "name": "Balancer",
+      "symbol": "BAL",
+      "decimals": 18,
+      "logoURI": "https://assets.coingecko.com/coins/images/11683/large/Balancer.png?1696511572",
+      "icon": "https://assets.coingecko.com/coins/images/11683/large/Balancer.png?1696511572"
+    }
+  ],
+  "message": null
+}

apps/cowswap-e2e-tests/src/mocks/bridge/fixtures/bungee-intermediate-tokens.json

@@ -0,0 +1,25 @@
+{
+  "success": true,
+  "statusCode": 200,
+  "result": [
+    {
+      "chainId": 1,
+      "address": "0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48",
+      "name": "USDC",
+      "symbol": "USDC",
+      "decimals": 6,
+      "logoURI": "https://assets.coingecko.com/coins/images/6319/large/USDC.png?1769615602",
+      "icon": "https://assets.coingecko.com/coins/images/6319/large/USDC.png?1769615602"
+    },
+    {
+      "chainId": 1,
+      "address": "0xdac17f958d2ee523a2206206994597c13d831ec7",
+      "name": "Tether",
+      "symbol": "USDT",
+      "decimals": 6,
+      "logoURI": "https://assets.coingecko.com/coins/images/325/large/Tether.png?1696501661",
+      "icon": "https://assets.coingecko.com/coins/images/325/large/Tether.png?1696501661"
+    }
+  ],
+  "message": null
+}