this.* not working with async/await javascript (node 8.6.0)

Question

I couldn't find why I get this error:

And here is my code:

  create: async (data) => {
    const insertedData = await dbProvider.query('INSERT INTO users SET ?', data);
    console.log(this);
    return await this.getById(insertedData.insertId);
  },
  getById: async (id) => {
    const data = await dbProvider.query('SELECT * From users WHERE id = ?', id);
    return data;
  },

Create gets called with await repo.create(data); the create calls this.getById which results in an error. Any idea why this happens?

This has nothing to do with `async`/`await` syntax. – Bergi Oct 01 '17 at 13:34 — Bergi, Oct 01 '17 at 13:34

score 2 · Answer 1 · answered Oct 01 '17 at 12:57

Because arrow functions are pre-bound to the lexical this.

If you want a dynamic this inside of a function, it cannot be an arrow function:

  async create(data) {
    const insertedData = await dbProvider.query('INSERT INTO users SET ?', data);
    console.log(this);
    return await this.getById(insertedData.insertId);
  },
  async getById(id) {
    const data = await dbProvider.query('SELECT * From users WHERE id = ?', id);
    return data;
  },

this.* not working with async/await javascript (node 8.6.0)

1 Answers1