import assert from "node:assert";
import { describe, it } from "node:test";
import { visibleWidth, wrapTextWithAnsi } from "../src/utils.js";
describe("regional indicator width regression", () => {
it("treats partial flag grapheme as full-width to avoid streaming render drift", () => {
const partialFlag = "🇨";
const listLine = " - 🇨";
assert.strictEqual(visibleWidth(partialFlag), 2);
assert.strictEqual(visibleWidth(listLine), 10);
});
it("wraps intermediate partial-flag list line before overflow", () => {
const wrapped = wrapTextWithAnsi(" - 🇨", 9);
assert.strictEqual(wrapped.length, 2);
assert.strictEqual(visibleWidth(wrapped[0] || ""), 7);
assert.strictEqual(visibleWidth(wrapped[1] || ""), 2);
});
it("treats all regional-indicator singleton graphemes as width 2", () => {
for (let cp = 0x1f1e6; cp <= 0x1f1ff; cp++) {
const regionalIndicator = String.fromCodePoint(cp);
assert.strictEqual(
visibleWidth(regionalIndicator),
2,
`Expected ${regionalIndicator} (U+${cp.toString(16).toUpperCase()}) to be width 2`,
);
}
});
it("keeps full flag pairs at width 2", () => {
const samples = ["🇯🇵", "🇺🇸", "🇬🇧", "🇨🇳", "🇩🇪", "🇫🇷"];
for (const flag of samples) {
assert.strictEqual(visibleWidth(flag), 2, `Expected ${flag} to be width 2`);
}
});
it("keeps common streaming emoji intermediates at stable width", () => {
const samples = ["👍", "👍🏻", "✅", "⚡", "⚡️", "👨", "👨💻", "🏳️🌈"];
for (const sample of samples) {
assert.strictEqual(visibleWidth(sample), 2, `Expected ${sample} to be width 2`);
}
});
});