patterns_typescript/email.test.ts

import { describe, it, expect } from "vitest";
import { detectEmail } from "./email.js";

describe("Email detection", () => {
  it("detects simple email", () => {
    const r = detectEmail("contact: foo@example.com");
    expect(r).toHaveLength(1);
    expect(r[0].value).toBe("foo@example.com");
    expect(r[0].type).toBe("EMAIL");
  });

  it("detects email with dots and dashes in local part", () => {
    expect(detectEmail("first.last-name@company.co.kr")).toHaveLength(1);
  });

  it("detects email with plus addressing", () => {
    const r = detectEmail("user+tag@gmail.com");
    expect(r).toHaveLength(1);
    expect(r[0].value).toBe("user+tag@gmail.com");
  });

  it("detects multi-label TLD (.co.kr)", () => {
    const r = detectEmail("hong@samsung.co.kr");
    expect(r).toHaveLength(1);
    expect(r[0].value).toBe("hong@samsung.co.kr");
  });

  it("detects multiple emails in one string", () => {
    const r = detectEmail("a@x.com 그리고 b@y.org");
    expect(r).toHaveLength(2);
  });

  it("detects email inside Korean sentence", () => {
    const r = detectEmail("제 이메일은 kim@klawn.io 입니다");
    expect(r).toHaveLength(1);
    expect(r[0].value).toBe("kim@klawn.io");
  });

  it("returns empty for plain text", () => {
    expect(detectEmail("이메일 없음")).toHaveLength(0);
  });

  it("returns empty for bare @ without domain", () => {
    expect(detectEmail("hello @ world")).toHaveLength(0);
  });

  it("returns empty for domain without TLD", () => {
    expect(detectEmail("user@localhost")).toHaveLength(0);
  });

  it("reports correct start/end positions", () => {
    const text = "before foo@bar.com after";
    const r = detectEmail(text);
    expect(r).toHaveLength(1);
    expect(text.slice(r[0].start, r[0].end)).toBe("foo@bar.com");
  });
});