AutistMask/tests/chainSwitchGate.test.js

// Who may move the active chain.
//
// wallet_switchEthereumChain used to be answered for any origin at all, with
// no connection check and no prompt, so a page the user had never connected
// to could clear the [TESTNET] banner under someone who believed they were
// on Sepolia (https://git.eeqj.de/sneak/AutistMask/issues/308). The refusal
// is asserted as a refusal to ACT — the state unmoved and no chainChanged
// broadcast — because an error code alone would not distinguish a gate from
// a switch that happened and then reported a failure.
//
// The endpoint half of that issue lives in tests/networkEndpoints.test.js,
// which covers the popup's chain switch; this file covers the background's,
// which goes through storage rather than the shared state singleton.

const { networkById } = require("../src/shared/networks");
const { makeStorageStub } = require("./support/storageStub");

const ADDRESS = "0x66133E8ea0f5D1d612D2502a968757D1048c214a";

// The site the persisted state has connected, and one it has never heard of.
const CONNECTED_ORIGIN = "https://dapp.example";
const CONNECTED_HOSTNAME = "dapp.example";
const STRANGER_ORIGIN = "https://stranger.example";

const MAINNET = networkById("mainnet");
const SEPOLIA = networkById("sepolia");

// The user's own node, so a switch that happens is visible as the loss of it.
const CUSTOM_RPC = "http://127.0.0.1:8545";

function walletFixture() {
    return [
        {
            name: "Wallet 1",
            type: "hd",
            addresses: [{ address: ADDRESS, balance: "0", tokenBalances: [] }],
        },
    ];
}

// Let the handler's promise chain run to the next suspension point. The gate
// reads storage before it answers, so the response is several awaits deep.
async function settle() {
    for (let i = 0; i < 50; i++) await Promise.resolve();
}

afterEach(() => {
    delete global.chrome;
});

// ---------------------------------------------------------------------------
// The gate: which origins the background will switch the chain for.
// ---------------------------------------------------------------------------

// Load the background worker against stubbed browser APIs, with the real
// chain-switch and persistence modules behind it, and return the handles to
// drive it.
function loadBackground() {
    jest.resetModules();

    jest.doMock("../src/shared/balances", () => ({
        getProvider: () => ({}),
        refreshBalances: jest.fn(async () => {}),
    }));
    jest.doMock("../src/shared/phishingDomains", () => ({
        isPhishingDomain: () => false,
    }));
    jest.doMock("../src/shared/alarms", () => ({
        BALANCE_REFRESH_ALARM: "balance",
        BALANCE_REFRESH_PERIOD_MINUTES: 1,
        ensureRecurringAlarms: jest.fn(async () => {}),
        registerAlarmHandlers: jest.fn(),
    }));

    // Storage is the only wallet state there is. The background reads and
    // writes it per call — it holds no in-memory copy and cannot reach the
    // shared singleton — so a switch that happened is visible here as a
    // written record, and one that did not is visible as its absence.
    const persisted = {
        networkId: "mainnet",
        rpcUrl: CUSTOM_RPC,
        blockscoutUrl: MAINNET.defaultBlockscoutUrl,
        networkEndpoints: {},
        wallets: walletFixture(),
        lastBalanceRefresh: 1,
        tokenHolderCache: {},
        fraudContracts: [],
        activeAddress: ADDRESS,
        allowedSites: { [ADDRESS]: [CONNECTED_HOSTNAME] },
        deniedSites: {},
    };
    const storage = makeStorageStub({ autistmask: persisted });

    let messageListener = null;
    // Every message the background pushed at a content script. chainChanged
    // is what tells a page the wallet moved, so an ungated switch is visible
    // here as well as in the state.
    const toTabs = [];

    global.chrome = {
        storage,
        runtime: {
            getURL: (path) => "chrome-extension://autistmask/" + path,
            onMessage: {
                addListener: (fn) => {
                    messageListener = fn;
                },
            },
            onConnect: { addListener: () => {} },
            lastError: null,
        },
        windows: {
            getLastFocused: (cb) => cb(null),
            create: (options, cb) => cb({ id: 1 }),
            remove: (id, cb) => {
                if (cb) cb();
            },
            onRemoved: { addListener: () => {} },
        },
        tabs: {
            query: (queryInfo, cb) => cb([{ id: 1 }]),
            sendMessage: (tabId, message, cb) => {
                toTabs.push(message);
                if (cb) cb();
            },
        },
        action: { setPopup: () => {} },
    };

    require("../src/background/index");

    async function switchChain(chainId, origin) {
        let result = null;
        messageListener(
            {
                type: "AUTISTMASK_RPC",
                method: "wallet_switchEthereumChain",
                params: [{ chainId }],
            },
            { origin },
            (r) => {
                result = r;
            },
        );
        await settle();
        return result;
    }

    return {
        switchChain,
        walletState: () => storage.read("autistmask"),
        chainChangedEvents: () =>
            toTabs.filter((m) => m.eventName === "chainChanged"),
    };
}

describe("wallet_switchEthereumChain is gated on the connection", () => {
    test("an origin the wallet was never connected to is refused with 4100", async () => {
        const bg = loadBackground();

        const result = await bg.switchChain(SEPOLIA.chainId, STRANGER_ORIGIN);

        expect(result.error).toEqual({ code: 4100, message: "Unauthorized" });
        expect(result.result).toBeUndefined();
        // The refusal has to be a refusal to ACT, not just an error string:
        // the wallet is still on mainnet, still on the user's own node, and
        // no page was told the chain moved.
        expect(bg.walletState().networkId).toBe("mainnet");
        expect(bg.walletState().rpcUrl).toBe(CUSTOM_RPC);
        expect(bg.chainChangedEvents()).toEqual([]);
    });

    test("an unconnected origin is refused even for the chain already active", async () => {
        const bg = loadBackground();

        const result = await bg.switchChain(MAINNET.chainId, STRANGER_ORIGIN);

        expect(result.error).toEqual({ code: 4100, message: "Unauthorized" });
    });

    test("an unconnected origin is refused before the unsupported-chain answer", async () => {
        const bg = loadBackground();

        const result = await bg.switchChain("0x89", STRANGER_ORIGIN);

        expect(result.error.code).toBe(4100);
    });

    test("a connected origin switches the chain", async () => {
        const bg = loadBackground();

        const result = await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);

        expect(result).toEqual({ result: null });
        expect(bg.walletState().networkId).toBe("sepolia");
        expect(bg.chainChangedEvents()).toEqual([
            {
                type: "AUTISTMASK_EVENT",
                eventName: "chainChanged",
                data: SEPOLIA.chainId,
            },
        ]);
    });

    test("a connected origin asking for an unsupported chain still gets 4902", async () => {
        const bg = loadBackground();

        const result = await bg.switchChain("0x89", CONNECTED_ORIGIN);

        expect(result.error.code).toBe(4902);
        expect(bg.walletState().networkId).toBe("mainnet");
    });

    test("a switch by a connected origin keeps the user's endpoint", async () => {
        const bg = loadBackground();

        await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);
        expect(bg.walletState().rpcUrl).toBe(SEPOLIA.defaultRpcUrl);

        await bg.switchChain(MAINNET.chainId, CONNECTED_ORIGIN);
        expect(bg.walletState().rpcUrl).toBe(CUSTOM_RPC);
    });
});