FileListをモックする（フロントエンドJavascriptテスト）

export const filesProcess = (fileList) => {
  if (
    Object.prototype.toString.call(fileList).split(" ")[1].slice(0, -1) !=
    "FileList"
  )
    throw Error("FileListを引数に入れるように!");

  for (let file of fileList) {
    console.log("ファイル名: " + file.name);
  }
};

    it("てすと", () => {
      const file = new File(["foo"], "foo.txt", {
        type: "text/plain",
      });
      const file2 = new File(["this is test file"], "test.txt", {
        type: "text/plain",
      });
      const input = document.createElement("input");
      input.setAttribute("type", "file");
      input.setAttribute("name", "file-upload");
      input.multiple = true;
      let mockFileList = Object.create(input.files); // FileListを継承してオブジェクトを作る
      mockFileList[0] = file;
      mockFileList[1] = file2;
      Object.defineProperty(mockFileList, "length", { value: 2 });
      console.log("型の詳細: " + Object.prototype.toString.call(mockFileList));
      filesProcess(mockFileList);
      expect(1).toBe(1); //FileListの作成を試したいのでダミー
    });