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

// Whether two seats can end up wanting the same pixels.
//
// The felt used to decide this from one number: the straight-line distance between the
// closest two *neighbouring* seats, judged against a fraction of a puck's width. Both
// halves of that were wrong, and the running page showed it. Measured across nine
// viewports and six table sizes:
//
//   seventeen of fifty-four tables had one seat's name or stack painted under another
//   ten of them had the collision between two seats that are not neighbours
//
// The second number is the interesting one. On a phone held sideways the felt is 528px
// wide and 87 tall, the ring is very nearly a straight line, and the seat that lands on
// top of you is the one across the table — seats 1 and 7, overlapping by 68px, while
// every neighbouring pair was fine and the check said the table was clean.
//
// The first is what a distance test can't fix even looking at every pair: distance has
// one number in it, and a puck is half again as wide as it is tall. 84px between centres
// is generous side by side and nowhere near enough on the diagonal.
const test = require("node:test");
const { describe } = require("node:test");
const assert = require("node:assert");
const fs = require("fs");
const path = require("path");
const { Render } = require("./load");

const CSS = fs.readFileSync(
    path.join(__dirname, "..", "..", "JoshHeaps.Net", "wwwroot", "css", "casino", "holdem.css"), "utf8");

describe("two boxes on a ring", () => {
    // A phone held sideways, once the action bar has taken its share: a felt far wider
    // than it is tall, on which the ring is very nearly a straight line.
    const felt = { width: 400, height: 70 };
    const flat = { rx: 44, ry: 42 };

    test("a pair that is not neighbours still counts", () => {
        // Eight seats, a 48x60 puck. Every neighbouring pair is clear. Seats 1 and 5 are
        // on top of each other, and so are 2 and 4, and 6 and 8 — the seat that lands on
        // you here is the one across the table, because the rim doubles back at the ends
        // of a shape this flat and a long walk apart is no distance at all.
        assert.equal(Render.seatsCollide(8, felt, flat, 48, 60), true);

        const neighbours = (count, w, h) => {
            const points = Render.ringPositions(count, flat.rx, flat.ry, felt.width / felt.height)
                .map(s => ({ x: (s.left / 100) * felt.width, y: (s.top / 100) * felt.height }));
            return points.some((point, i) => {
                const next = points[(i + 1) % points.length];
                return Math.abs(point.x - next.x) < w && Math.abs(point.y - next.y) < h;
            });
        };
        assert.equal(neighbours(8, 48 + Render.SEAT_CLEARANCE_PX, 60 + Render.SEAT_CLEARANCE_PX), false,
            "no neighbouring pair overlaps, which is exactly why this had to look at all of them");
    });

    test("and the answer is the box, not a radius", () => {
        // Two seats 60px apart across and 35px down, with a 64x40 puck. The distance
        // between them is 69px, so the test this replaces — "are these two further apart
        // than a puck is wide?" — called it clear. The boxes overlap by 4px by 5px.
        const boxes = { width: 200, height: 100 };
        const twoSeats = (dx, dy) => {
            const original = Render.ringPositions;
            Render.ringPositions = () => [
                { left: 50 - (dx / 2 / boxes.width) * 100, top: 50 - (dy / 2 / boxes.height) * 100 },
                { left: 50 + (dx / 2 / boxes.width) * 100, top: 50 + (dy / 2 / boxes.height) * 100 },
            ];
            try {
                return Render.seatsCollide(2, boxes, flat, 64, 40, 0);
            } finally {
                Render.ringPositions = original;
            }
        };
        assert.ok(Math.hypot(60, 35) > 64, "and a distance test would have passed it");
        assert.equal(twoSeats(60, 35), true, "60 across and 35 down, with a 64x40 puck");
        assert.equal(twoSeats(60, 45), false, "far enough apart vertically");
        assert.equal(twoSeats(66, 10), false, "far enough apart horizontally");
    });

    test("with daylight, so rounded corners don't read as touching", () => {
        assert.ok(Render.SEAT_CLEARANCE_PX > 0);
    });

    test("a table nobody is sitting at can't collide with itself", () => {
        assert.equal(Render.seatsCollide(1, felt, flat, 96, 60), false);
        assert.equal(Render.seatsCollide(9, null, flat, 96, 60), false);
    });
});

describe("the widths the felt may choose from", () => {
    test("run widest first, because the widest that fits is the one wanted", () => {
        const widths = Render.seatWidthCandidates();
        widths.slice(1).forEach((w, i) => assert.ok(w < widths[i], `${widths[i]} then ${w}`));
    });

    test("and span the whole declared range", () => {
        const widths = Render.seatWidthCandidates();
        assert.equal(widths[0], Render.SEAT_WIDTH_MAX);
        assert.equal(widths[widths.length - 1], Render.SEAT_WIDTH_MIN);
    });

    test("the floor is still a name, not a smudge", () => {
        // At 44px the tight layout shows about five characters and an ellipsis. Below
        // that a puck stops telling the dealer who is sitting there, which is the one
        // thing on the felt it exists to say.
        assert.ok(Render.SEAT_WIDTH_MIN >= 44);
        assert.ok(Render.SEAT_TIGHT_BELOW_PX > Render.SEAT_WIDTH_MIN);
        assert.ok(Render.SEAT_TIGHT_BELOW_PX < Render.SEAT_WIDTH_MAX);
    });

    test("and there are few enough of them to measure after every tap", () => {
        // Each one costs a forced layout. Ten is the budget; the cache carries the rest.
        assert.ok(Render.seatWidthCandidates().length <= 12);
    });
});

describe("what the stylesheet has to keep holding up", () => {
    test("the puck's width comes from the property, not from a breakpoint", () => {
        // Three media queries used to declare it — 78px, 64px and 62px — three guesses
        // at a number that depends on how many people are sitting down, which no media
        // query can see. The same 390px phone has room for 90px at four seats and 61 at
        // nine.
        const declarations = CSS.replace(/\/\*[\s\S]*?\*\//g, "");
        const seatRules = [...declarations.matchAll(/(^|[,}])\s*(\.seat)\s*\{([^}]*)\}/g)]
            .map(m => m[3]);
        const hardWidths = seatRules
            .flatMap(body => body.match(/(?<![\w-])width:\s*[^;]+/g) || [])
            .filter(decl => !decl.includes("var(--seatPuckW"));
        assert.deepEqual(hardWidths, []);
    });

    test("the puck measures what it says it measures", () => {
        // As content-box a 64px puck came out 74 across once its padding and border were
        // counted, and the search compares that number against distances on the felt.
        const rule = CSS.match(/\n\.seat \{[^}]*\}/);
        assert.ok(rule, ".seat rule not found");
        assert.match(rule[0], /box-sizing:\s*border-box/);
    });

    test("and a blind badge never reaches sideways off its own puck", () => {
        // This is what makes the footprint the puck and nothing more. The badge's
        // remaining overhang is vertical, and it points away from the table at both ends
        // — `top` on the upper arc, `bottom` on the lower — so two seats facing each
        // other across the felt wear their badges back to back.
        //
        // It was not always so: at `left: -6px` the small blind hung off the puck's left
        // corner, and on an iPhone Pro Max at six seats — pucks not touching at all —
        // "SB" was painted across the next player's $1,137.
        const badges = [...CSS.matchAll(/\.(sb|bb|str)Badge\s*\{([^}]*)\}/g)];
        assert.equal(badges.length, 3, "expected all three blind badges");
        badges.forEach(([, which, body]) => {
            const left = body.match(/(?<![\w-])left:\s*(-?[\d.]+)px/);
            assert.ok(left, `.${which}Badge should place itself horizontally`);
            assert.ok(Number(left[1]) >= 0,
                `.${which}Badge sits at ${left[1]}px, off the left of its own puck`);
        });
    });

    test("and all three sit in the same place, so there is one spot to look at", () => {
        // Two badges in two positions means the dealer's eye has to find which of them
        // this seat is using before it can read which blind it is, forty times a night.
        // A seat only ever wears one: the blinds are different players by construction,
        // and the straddle chain starts left of the big blind and stops short of the
        // small one.
        const lefts = [...CSS.matchAll(/\.(sb|bb|str)Badge\s*\{([^}]*)\}/g)]
            .map(([, , body]) => (body.match(/(?<![\w-])left:\s*(-?[\d.]+px)/) || [])[1]);
        assert.equal(new Set(lefts).size, 1, `badges sit at ${lefts.join(", ")}`);
    });
});

describe("the blind badge counts", () => {
    // It didn't, for a while, and the reasoning had one hole in it. The badge hangs 9px
    // off the puck and always points away from the table — `top: -9px` on the upper arc,
    // `bottom: -9px` on the lower — so two seats facing each other across the felt wear
    // them back to back and it costs nothing. That much is true.
    //
    // What was also claimed is that two seats on the *same* arc "wear them at the same
    // height, offset by exactly as much as the pucks are". True of a straight rail,
    // false of a ring: neighbours on a curve sit at different heights, so the badge
    // pointing away from the table on one of them points at the corner of the other.
    // Measured on the running page, three tables in the sweep had a player's stack
    // painted under the next player's SB or BB — and the badge outranks everything else
    // on the felt, so what the dealer reads in that spot is the wrong number entirely.
    test("a seat needs room for the badge it might be wearing", () => {
        const puck = { width: 64, height: 40 };
        assert.deepEqual(Render.seatFootprint(puck),
            { width: 64, height: 40 + Render.SEAT_BADGE_OVERHANG_PX });
    });

    test("sideways it costs nothing, because the badge doesn't go sideways", () => {
        // It sits inside the puck's own width — see "all three sit in the same place"
        // above, which holds the stylesheet to it.
        assert.equal(Render.seatFootprint({ width: 64, height: 40 }).width, 64);
    });

    test("the number here is the number the stylesheet draws", () => {
        // Two files have to agree about one distance: holdem.css hangs the badge off the
        // puck by it, render.js charges every chair in the ring for it. They are wired
        // together by nothing but this test. Drift either way is silent — too small and
        // badges land on neighbours again, too large and every puck on a nine-handed
        // phone gives up a size step for clearance nothing needs.
        const top = CSS.match(/\.blindBadge \{[^}]*?(?<![\w-])top:\s*(-?[\d.]+)px/);
        const bottom = CSS.match(/\.seat\.seatBelowCentre \.blindBadge \{[^}]*?(?<![\w-])bottom:\s*(-?[\d.]+)px/);
        assert.ok(top && bottom, "the badge should hang off both arcs");
        assert.equal(Math.abs(Number(top[1])), Render.SEAT_BADGE_OVERHANG_PX);
        assert.equal(Math.abs(Number(bottom[1])), Render.SEAT_BADGE_OVERHANG_PX,
            "the same distance at both ends, or one arc is charged for the other's badge");
    });

    test("and it is counted once, not once per seat", () => {
        // seatsCollide is given one box and compares centres against it, so the
        // separation it asks for is one puck plus one badge. That is exactly right for
        // two seats on the same arc each wearing one, and generous for the far commoner
        // case where only one of the two is in the blinds at all. Counting it on both
        // sides is what made a landscape table unsatisfiable the first time this was
        // tried, back when that felt was 87px tall.
        const puck = { width: 64, height: 40 };
        const grew = Render.seatFootprint(puck).height - puck.height;
        assert.equal(grew, Render.SEAT_BADGE_OVERHANG_PX);
        assert.ok(grew < 2 * Render.SEAT_BADGE_OVERHANG_PX);
    });
});

describe("with no browser to measure", () => {
    test("nothing here throws", () => {
        assert.equal(Render.measuredSeatBox(), null);
        assert.equal(Render.seatFootprint(null), null);
    });
});