tests/download.test.js

import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
import { downloadBlob } from "../src/view/download.js";
import { STUBS } from "./api.js";
/** @test {downloadBlob} */
describe("downloadBlob", () => {
  let anchor;
  beforeEach(() => {
    anchor = STUBS.anchor();
    STUBS.url();
    STUBS.documentDownload(anchor);
  });
  afterEach(() => vi.unstubAllGlobals());
  /** @test {downloadBlob} */
  it("triggers an anchor download with stem return; accepts a direct Blob or decodes Base64 to audio/midi with a default UTC-timestamp filename", () => {
    expect(downloadBlob(new Blob(["x"]), "output.mid")).toBe("output");
    expect(anchor.href).toBe("blob:mock");
    expect(anchor.download).toBe("output.mid");
    expect(downloadBlob(btoa("hello"))).toMatch(
      /^\d{4}-\d{2}-\d{2}T\d{2}-\d{2}-\d{2}$/,
    );
    const blob = URL.createObjectURL.mock.calls[1][0];
    expect(blob).toBeInstanceOf(Blob);
    expect(blob.type).toBe("audio/midi");
    expect(anchor.click).toHaveBeenCalledTimes(2);
    expect(anchor.remove).toHaveBeenCalledTimes(2);
  });
});