import assert from "node:assert";
import { describe, it } from "node:test";
import { fuzzyFilter, fuzzyFilterScored, fuzzyMatch } from "../src/fuzzy.js";
describe("fuzzyMatch", () => {
it("empty query matches everything with score 0", () => {
const result = fuzzyMatch("", "anything");
assert.strictEqual(result.matches, true);
assert.strictEqual(result.score, 0);
});
it("query longer than text does not match", () => {
const result = fuzzyMatch("longquery", "short");
assert.strictEqual(result.matches, false);
});
it("exact match has good score", () => {
const result = fuzzyMatch("test", "test");
assert.strictEqual(result.matches, true);
assert.ok(result.score < 0); // Should be negative due to consecutive bonuses
});
it("characters must appear in order", () => {
const matchInOrder = fuzzyMatch("abc", "aXbXc");
assert.strictEqual(matchInOrder.matches, true);
const matchOutOfOrder = fuzzyMatch("abc", "cba");
assert.strictEqual(matchOutOfOrder.matches, false);
});
it("case insensitive matching", () => {
const result = fuzzyMatch("ABC", "abc");
assert.strictEqual(result.matches, true);
const result2 = fuzzyMatch("abc", "ABC");
assert.strictEqual(result2.matches, true);
});
it("consecutive matches score better than scattered matches", () => {
const consecutive = fuzzyMatch("foo", "foobar");
const scattered = fuzzyMatch("foo", "f_o_o_bar");
assert.strictEqual(consecutive.matches, true);
assert.strictEqual(scattered.matches, true);
assert.ok(consecutive.score < scattered.score);
});
it("word boundary matches score better", () => {
const atBoundary = fuzzyMatch("fb", "foo-bar");
const notAtBoundary = fuzzyMatch("fb", "afbx");
assert.strictEqual(atBoundary.matches, true);
assert.strictEqual(notAtBoundary.matches, true);
assert.ok(atBoundary.score < notAtBoundary.score);
});
it("matches swapped alpha numeric tokens", () => {
const result = fuzzyMatch("codex52", "gpt-5.2-codex");
assert.strictEqual(result.matches, true);
});
});
describe("fuzzyFilter", () => {
it("empty query returns all items unchanged", () => {
const items = ["apple", "banana", "cherry"];
const result = fuzzyFilter(items, "", (x: string) => x);
assert.deepStrictEqual(result, items);
});
it("filters out non-matching items", () => {
const items = ["apple", "banana", "cherry"];
const result = fuzzyFilter(items, "an", (x: string) => x);
assert.ok(result.includes("banana"));
assert.ok(!result.includes("apple"));
assert.ok(!result.includes("cherry"));
});
it("sorts results by match quality", () => {
const items = ["a_p_p", "app", "application"];
const result = fuzzyFilter(items, "app", (x: string) => x);
assert.strictEqual(result[0], "app");
});
it("prioritizes exact matches over longer prefix matches", () => {
const items = ["clone", "cl"];
const result = fuzzyFilter(items, "cl", (x: string) => x);
assert.deepStrictEqual(result, ["cl", "clone"]);
});
it("works with custom getText function", () => {
const items = [
{ name: "foo", id: 1 },
{ name: "bar", id: 2 },
{ name: "foobar", id: 3 },
];
const result = fuzzyFilter(items, "foo", (item: { name: string; id: number }) => item.name);
assert.strictEqual(result.length, 2);
assert.ok(result.map((r) => r.name).includes("foo"));
assert.ok(result.map((r) => r.name).includes("foobar"));
});
});
describe("fuzzyFilterScored", () => {
it("empty query returns all items with score 0", () => {
const items = ["apple", "banana"];
const result = fuzzyFilterScored(items, "", (x: string) => x);
assert.deepStrictEqual(
result.map((r) => r.item),
items,
);
assert.ok(result.every((r) => r.score === 0));
});
it("returns scores sorted best-first", () => {
const items = ["a_p_p", "app"];
const result = fuzzyFilterScored(items, "app", (x: string) => x);
assert.strictEqual(result[0]?.item, "app");
assert.ok(result[0].score <= (result[1]?.score ?? Infinity));
});
it("assigns equal scores to equally-good matches, enabling a stable tie-break", () => {
const items = ["glm-5", "glm-5.1", "glm-5.2"];
const result = fuzzyFilterScored(items, "glm", (x: string) => x);
assert.strictEqual(result.length, 3);
assert.strictEqual(result[0]?.score, result[1]?.score);
assert.strictEqual(result[1]?.score, result[2]?.score);
});
});