damerauLevenshtein.test.ts

import { describe, expect, it } from "vitest";

import damerauLevenshtein from "./damerauLevenshtein";

// https://github.com/aldebaran/libport/blob/master/tests/libport/damerau-levenshtein-distance.cc

describe("damerauLevenshtein", () => {
  const emptyString = "";

  it("should pass, empty strings", () => {
    const distance = damerauLevenshtein(emptyString, emptyString);
    // eslint-disable-next-line @typescript-eslint/no-magic-numbers
    expect(distance).toBe(0);
  });

  it("should pass, distance 0", () => {
    const s = "cat";
    const distance = damerauLevenshtein(s, s);
    // eslint-disable-next-line @typescript-eslint/no-magic-numbers
    expect(distance).toBe(0);
  });

  it("should pass, 100% distance", () => {
    const s2 = "test";
    const expectedDistance = s2.length;
    const distance = damerauLevenshtein(emptyString, s2);
    expect(distance).toBe(expectedDistance);
  });

  it("should pass, cat and dog", () => {
    const distance = damerauLevenshtein("cat", "dog");
    // eslint-disable-next-line @typescript-eslint/no-magic-numbers
    expect(distance).toBe(3);
  });

  it("should pass, deletion", () => {
    const distance = damerauLevenshtein("azertyuiop", "aeryuop");
    // eslint-disable-next-line @typescript-eslint/no-magic-numbers
    expect(distance).toBe(3);
  });

  it("should pass, insertion", () => {
    const distance = damerauLevenshtein("aeryuop", "azertyuiop");
    // eslint-disable-next-line @typescript-eslint/no-magic-numbers
    expect(distance).toBe(3);
  });

  it("should pass, substitution", () => {
    const distance = damerauLevenshtein(
      "azertyuiopqsdfghjklmwxcvbn,",
      "qwertyuiopasdfghjkl;zxcvbnm"
    );
    // eslint-disable-next-line @typescript-eslint/no-magic-numbers
    expect(distance).toBe(6);
  });

  it("should pass, transposition", () => {
    const distance = damerauLevenshtein("1234567890", "1324576809");
    // eslint-disable-next-line @typescript-eslint/no-magic-numbers
    expect(distance).toBe(3);
  });
});