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

// The stylesheet has to keep picking from the scales.
//
// Before the token block went in, holdem.css used 42 different spacing values, 31 font
// sizes, 14 border-radii and 139 colours, and defined three custom properties. None of
// that was anybody's decision — each number was chosen at the moment it was needed, and
// the result read as crowded even where nothing overlapped, because a 0.42rem gap next
// to a 0.45rem gap next to a 0.5rem gap gives the eye no rhythm to lock onto.
//
// A one-off cleanup would last until the next `padding: 0.35rem`. So the scales are
// checked here instead: a new value has to be a step on one of them, or an exception
// with a reason written next to it.
//
// This reads the stylesheet as text rather than through a CSS parser, on purpose — the
// rest of this suite has no dependencies and runs in a second, and a regex over
// declarations is enough to catch the thing that actually happens, which is somebody
// (me) typing a number instead of reaching for a token.
const test = require("node:test");
const { describe } = require("node:test");
const assert = require("node:assert");
const fs = require("fs");
const path = require("path");

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

// Comments carry measurements and rationale — "measured at 342px tall on a phone" —
// and none of that is a declaration. Strip them before looking for values.
const declarations = css.replace(/\/\*[\s\S]*?\*\//g, "");

// Everything after the token block. The :root block is where the raw values are
// supposed to be.
const body = declarations.slice(declarations.indexOf("#potBadgeAmount,"));

const valuesIn = (properties, source = body) => {
    const found = [];
    // The lookbehind rejects a hyphen as well as a word character, so `scroll-padding`
    // isn't read as `padding`. It caught the pot wizard's scroll-padding the moment
    // that went in — correctly by its own rules, wrongly in substance: those two values
    // are the measured heights of the dialog's sticky header and footer, a clearance
    // like the action bar's, not a step in the spacing rhythm.
    const re = new RegExp(`(?<![\\w-])(${properties.join("|")})\\s*:([^;}]*)`, "g");
    let m;
    while ((m = re.exec(source)) !== null) {
        const [, prop, value] = m;
        // calc() and env() do their own arithmetic on tokens; the tokens inside them
        // are still checked, because the regex below looks at bare numbers only.
        (value.match(/(?<![\w-])[0-9.]+(rem|px|em)\b/g) || []).forEach(v => found.push({ prop, value: v }));
    }
    return found;
};

describe("the spacing scale", () => {
    // Hairlines and structural clearances, each one deliberate:
    //   0px/1px/3px/4px/22px — borders, hairline offsets, and the 22px of room a seat
    //                          puck's name gives the dealer button beside it.
    //   5rem/9rem            — how far the page has to scroll past the fixed action
    //                          bar. Not rhythm; clearance for a thing of a known size.
    const ALLOWED = new Set(["0px", "1px", "2px", "3px", "4px", "22px", "5rem", "9rem"]);

    test("every gap, margin and padding comes off the scale", () => {
        const offenders = valuesIn(
            ["padding", "padding-top", "padding-right", "padding-bottom", "padding-left",
             "margin", "margin-top", "margin-right", "margin-bottom", "margin-left",
             "gap", "row-gap", "column-gap"])
            .filter(v => !ALLOWED.has(v.value));

        assert.deepEqual(offenders, [],
            "use var(--sp-0 … --sp-6), or add the value to ALLOWED with a reason");
    });

    test("and the scale is the one the tokens define", () => {
        ["--sp-0", "--sp-1", "--sp-2", "--sp-3", "--sp-4", "--sp-5", "--sp-6"]
            .forEach(token => assert.match(css, new RegExp(`\\${token}:`), `${token} is not defined`));
    });
});

describe("the type scale", () => {
    //   16px  — the size below which iOS zooms the page when a field is focused, so
    //           every text input states it. Not a typographic choice.
    //   1.05em, 0.44rem — relative bumps inside a component, and the shrink-to-fit for
    //           a six-figure stack on a 58px seat puck.
    const ALLOWED = new Set(["16px", "1.05em", "0.44rem"]);

    test("every font-size comes off the scale", () => {
        const offenders = valuesIn(["font-size"]).filter(v => !ALLOWED.has(v.value));
        assert.deepEqual(offenders, [],
            "use var(--fs-2xs … --fs-2xl), or add the value to ALLOWED with a reason");
    });

    test("and the scale is the one the tokens define", () => {
        ["--fs-2xs", "--fs-xs", "--fs-sm", "--fs-base", "--fs-md", "--fs-lg", "--fs-xl", "--fs-2xl"]
            .forEach(token => assert.match(css, new RegExp(`\\${token}:`), `${token} is not defined`));
    });
});

describe("the corner scale", () => {
    test("every border-radius comes off it", () => {
        const offenders = valuesIn(["border-radius"]).filter(v => v.value !== "2px");
        assert.deepEqual(offenders, [], "use var(--r-sm | --r-md | --r-lg | --r-pill)");
    });
});

describe("the tokens themselves", () => {
    test("every var() the stylesheet reaches for exists", () => {
        const used = new Set((css.match(/var\((--[a-zA-Z0-9-]+)/g) || []).map(s => s.slice(4)));
        // Published from JS at runtime rather than declared here — see actionBar.js.
        const fromScript = new Set(["--actionBarHeight", "--feltRoomPx"]);
        // Defined by the site's own stylesheet, not this one.
        const fromSite = new Set(["--font-mono"]);
        const missing = [...used].filter(t =>
            !fromScript.has(t) && !fromSite.has(t) && !new RegExp(`\\${t}\\s*:`).test(css));
        assert.deepEqual(missing, []);
    });

    test("and the dark surfaces stay off pure black", () => {
        // Shadows are invisible on #000, so depth has to come from a lighter surface —
        // and white text on true black is the pairing that smears on an OLED phone,
        // which is what this tool is used on.
        const surfaces = [...css.matchAll(/--surface-\d+:\s*(#[0-9a-fA-F]{3,8})/g)].map(m => m[1].toLowerCase());
        assert.ok(surfaces.length >= 4, "the surface ramp should have four steps");
        surfaces.forEach(hex => {
            assert.notEqual(hex, "#000");
            assert.notEqual(hex, "#000000");
        });
    });
});

describe("numbers that change while the dealer watches", () => {
    test("are set in tabular figures", () => {
        // A "1" is narrower than an "8" in a proportional face, so a pot ticking from
        // $18 to $21 shuffles its digits sideways and the eye reads movement where
        // there is only arithmetic.
        assert.match(css, /font-variant-numeric:\s*tabular-nums/);
        ["#potBadgeAmount", ".seatPuckStack", ".actionPot", ".standingsRow"]
            .forEach(sel => assert.ok(css.includes(sel),
                `${sel} should be in the tabular-figures list`));
    });
});

describe("controls that must not resize under a thumb", () => {
    test("the undo pill has a fixed width, not a content width", () => {
        // It names the last action, so its label changes on every tap. Measured across
        // one hand before this: 148, 110, 109, 108, 109, 110, 120.
        const rule = css.match(/\.actionUndo\s*\{[^}]*\}/);
        assert.ok(rule, ".actionUndo rule not found");
        assert.match(rule[0], /width:\s*[0-9.]+rem/);
    });

    test("and its label is the part that ellipsizes", () => {
        const rule = css.match(/\.actionUndoLabel\s*\{[^}]*\}/);
        assert.ok(rule, ".actionUndoLabel rule not found");
        assert.match(rule[0], /text-overflow:\s*ellipsis/);
    });
});