JoshHeaps.Net/tests/holdem/wakeLock.test.js

// When the tool asks the phone to stay awake, and — the part that actually matters —
// when it lets go again.
//
// A dealer's phone lies face-up on the felt all night. Left alone it dims and locks
// between the flop and the turn, every hand, and a dozen rounds of making the next step
// readable at a glance count for nothing behind a lock screen.
//
// The risk runs the other way too, and it is the one worth testing. A wake lock that is
// taken and not dropped is a phone that burns its battery through a break, a re-buy, and
// the twenty minutes everyone spends arguing about pizza — and the dealer has no way to
// tell that is what is happening. So the rule is narrow: held only while betting is
// actually open, and only while the dealer wants it.
//
// The browser side of this is a stand-in below rather than a real navigator, which lets
// the tests ask the questions a real table asks: what happens when the hand ends inside
// the request, what happens when the phone takes the lock back on its own, and what
// happens when the browser simply says no.
const test = require("node:test");
const { describe, beforeEach, afterEach } = require("node:test");
const assert = require("node:assert");
const { WakeLock, HoldemState, makeTable } = require("./load");

// A stand-in for navigator.wakeLock that records what was asked of it. `deny` makes
// every request reject, the way a phone in battery saver does.
const fakeWakeLock = ({ deny = false } = {}) => {
    const api = {
        requests: 0,
        released: 0,
        live: [],
        deny,
        wakeLock: {
            request: async () => {
                api.requests += 1;
                if (api.deny) throw new Error("denied");
                const listeners = [];
                const sentinel = {
                    released: false,
                    addEventListener: (name, fn) => { if (name === "release") listeners.push(fn); },
                    release: async () => {
                        if (sentinel.released) return;
                        sentinel.released = true;
                        api.released += 1;
                        listeners.forEach(fn => fn());
                    },
                    // What the browser does on its own when the tab stops being visible.
                    dropFromOutside: () => {
                        sentinel.released = true;
                        listeners.forEach(fn => fn());
                    },
                };
                api.live.push(sentinel);
                return sentinel;
            },
        },
    };
    return api;
};

// Settles the promises `sync()` deliberately doesn't return — it is called from
// renderAll, which is synchronous, so the acquiring happens off to one side.
const settle = () => new Promise(resolve => setImmediate(resolve));

// Node has had its own `globalThis.navigator` since v21, defined as a getter — so a
// plain assignment to it does nothing at all and throws nothing either. Every test in
// here that thought it had installed a fake would have been quietly measuring Node's
// real navigator, which has no wakeLock, and passing for the wrong reason.
const setNavigator = value => {
    Object.defineProperty(globalThis, "navigator", {
        value, configurable: true, writable: true,
    });
};

let realNavigator;

beforeEach(() => {
    realNavigator = globalThis.navigator;
    WakeLock.sentinel = null;
    WakeLock.wanted = false;
    WakeLock.pending = false;
    WakeLock.told = true; // The toast is DOM; it is checked in the browser.
    WakeLock.hooks = null;
});

afterEach(() => {
    setNavigator(realNavigator);
});

const useFake = api => {
    setNavigator(api);
    return api;
};

// A table mid-hand, which is the only state that wants the screen.
const dealtIn = () => {
    const state = makeTable({ seatCount: 4, stack: 200 });
    state.bettingOpen = true;
    return state;
};

describe("the rule about when a table needs the screen", () => {
    test("a hand in progress does", () => {
        assert.equal(WakeLock.shouldHold(dealtIn()), true);
    });

    test("a table between hands does not", () => {
        const state = dealtIn();
        state.bettingOpen = false;
        assert.equal(WakeLock.shouldHold(state), false);
    });

    test("a dealer who turned it off does not, mid-hand or otherwise", () => {
        const state = dealtIn();
        state.keepScreenAwake = false;
        assert.equal(WakeLock.shouldHold(state), false);
    });

    test("no table at all does not", () => {
        assert.equal(WakeLock.shouldHold(null), false);
        assert.equal(WakeLock.shouldHold(undefined), false);
    });

    test("a table that has never heard of the setting still does", () => {
        // Every saved table from before this existed. The migration fills it in, but the
        // rule itself has to read a missing value as yes or the first hand after an
        // update runs without it.
        const state = dealtIn();
        delete state.keepScreenAwake;
        assert.equal(WakeLock.shouldHold(state), true);
    });
});

describe("taking the lock and giving it back", () => {
    test("a hand starting takes one", async () => {
        const api = useFake(fakeWakeLock());
        WakeLock.sync(dealtIn());
        await settle();
        assert.equal(api.requests, 1);
        assert.ok(WakeLock.sentinel);
    });

    test("the hand ending gives it back", async () => {
        const api = useFake(fakeWakeLock());
        const state = dealtIn();
        WakeLock.sync(state);
        await settle();

        state.bettingOpen = false;
        WakeLock.sync(state);
        await settle();

        assert.equal(api.released, 1);
        assert.equal(WakeLock.sentinel, null);
    });

    test("turning the setting off mid-hand gives it back", async () => {
        const api = useFake(fakeWakeLock());
        const state = dealtIn();
        WakeLock.sync(state);
        await settle();

        state.keepScreenAwake = false;
        WakeLock.sync(state);
        await settle();

        assert.equal(api.released, 1);
    });

    test("a whole street of renders takes exactly one", async () => {
        // sync() runs off renderAll, which fires many times a second while a street is
        // being bet. Every one of those must be a no-op, or the tool leaks a sentinel
        // per render and the screen stays lit long after the hand is over.
        const api = useFake(fakeWakeLock());
        const state = dealtIn();
        for (let i = 0; i < 20; i += 1) {
            WakeLock.sync(state);
            await settle();
        }
        assert.equal(api.requests, 1);
        assert.equal(api.released, 0);
    });

    test("two syncs in the same tick still take exactly one", async () => {
        // The `pending` guard. Without it both calls get past the "already holding one?"
        // check, and the second sentinel is never stored — so nothing can release it and
        // the screen stays awake for the rest of the night.
        const api = useFake(fakeWakeLock());
        const state = dealtIn();
        WakeLock.sync(state);
        WakeLock.sync(state);
        await settle();
        await settle();
        assert.equal(api.requests, 1);
    });
});

describe("the awkward moments", () => {
    test("a hand that ends while the request is in flight leaves nothing held", async () => {
        // A fold can end the hand between asking for the lock and being given it. The
        // sentinel that arrives afterwards belongs to a hand that no longer exists.
        const api = useFake(fakeWakeLock());
        const state = dealtIn();
        WakeLock.sync(state);

        state.bettingOpen = false;
        WakeLock.sync(state);

        await settle();
        await settle();

        assert.equal(WakeLock.sentinel, null, "nothing should still be held");
        assert.equal(api.released, 1, "the one that arrived late should have been let go");
    });

    test("the browser taking it back leaves us able to take it again", async () => {
        // What happens every time the dealer switches apps to check a rule. The browser
        // releases the lock itself and never gives it back; if we go on believing we
        // hold one, the screen sleeps for the rest of the night.
        const api = useFake(fakeWakeLock());
        const state = dealtIn();
        WakeLock.sync(state);
        await settle();

        api.live[0].dropFromOutside();
        assert.equal(WakeLock.sentinel, null, "the release listener should have cleared it");

        WakeLock.sync(state);
        await settle();
        assert.equal(api.requests, 2, "coming back to the tool should take a fresh one");
    });

    test("a browser that says no is not an error", async () => {
        const api = useFake(fakeWakeLock({ deny: true }));
        const state = dealtIn();
        await assert.doesNotReject(async () => {
            WakeLock.sync(state);
            await settle();
        });
        assert.equal(api.requests, 1);
        assert.equal(WakeLock.sentinel, null);
    });

    test("a browser without the API is left alone entirely", async () => {
        useFake({});
        assert.equal(WakeLock.supported(), false);
        const state = dealtIn();
        await assert.doesNotReject(async () => {
            WakeLock.sync(state);
            await settle();
        });
        assert.equal(WakeLock.wanted, false);
    });
});

describe("what a saved table remembers about the screen", () => {
    test("a new table keeps the screen on", () => {
        assert.equal(HoldemState.createDefault().keepScreenAwake, true);
    });

    test("a table saved before the setting existed keeps the screen on", () => {
        const saved = HoldemState.createDefault();
        delete saved.keepScreenAwake;
        assert.equal(HoldemState.migrate(saved).keepScreenAwake, true);
    });

    test("a dealer who turned it off still has it off after a reload", () => {
        const saved = HoldemState.createDefault();
        saved.keepScreenAwake = false;
        assert.equal(HoldemState.migrate(saved).keepScreenAwake, false);
    });

    test("junk in that field is read as on rather than trusted", () => {
        const saved = HoldemState.createDefault();
        saved.keepScreenAwake = "yes please";
        assert.equal(HoldemState.migrate(saved).keepScreenAwake, true);
    });
});