axios/tests/unit/core/settle.test.js

import { describe, it, expect, vi } from 'vitest';
import settle from '../../../lib/core/settle.js';
import AxiosError from '../../../lib/core/AxiosError.js';

/**
 * Builds a minimal response object that settle() expects.
 * @param {number} status - HTTP status code
 * @param {Function} [validateStatus] - optional custom validator
 */
function makeResponse(status, validateStatus = (s) => s >= 200 && s < 300) {
  return {
    status,
    config: { validateStatus },
    request: {},
    data: null,
    headers: {},
  };
}

describe('core::settle', () => {
  describe('resolves the promise', () => {
    it('resolves for a 200 status by default', () => {
      const resolve = vi.fn();
      const reject = vi.fn();
      settle(resolve, reject, makeResponse(200));
      expect(resolve).toHaveBeenCalledTimes(1);
      expect(reject).not.toHaveBeenCalled();
    });

    it('resolves when validateStatus is not provided', () => {
      const resolve = vi.fn();
      const reject = vi.fn();
      const response = makeResponse(500);
      response.config.validateStatus = null;
      settle(resolve, reject, response);
      expect(resolve).toHaveBeenCalledTimes(1);
    });

    it('resolves when status is 0 (no response, e.g. network error)', () => {
      const resolve = vi.fn();
      const reject = vi.fn();
      const response = makeResponse(0);
      settle(resolve, reject, response);
      expect(resolve).toHaveBeenCalledTimes(1);
    });
  });

  describe('error code assignment', () => {
    it('assigns ERR_BAD_REQUEST for a 400 status', () => {
      const resolve = vi.fn();
      const reject = vi.fn();
      settle(resolve, reject, makeResponse(400, () => false));
      expect(reject).toHaveBeenCalledTimes(1);
      const error = reject.mock.calls[0][0];
      expect(error).toBeInstanceOf(AxiosError);
      expect(error.code).toBe(AxiosError.ERR_BAD_REQUEST);
    });

    it('assigns ERR_BAD_REQUEST for a 404 status', () => {
      const resolve = vi.fn();
      const reject = vi.fn();
      settle(resolve, reject, makeResponse(404, () => false));
      const error = reject.mock.calls[0][0];
      expect(error.code).toBe(AxiosError.ERR_BAD_REQUEST);
    });

    it('assigns ERR_BAD_REQUEST for a 499 status (top of 4xx range)', () => {
      const resolve = vi.fn();
      const reject = vi.fn();
      settle(resolve, reject, makeResponse(499, () => false));
      const error = reject.mock.calls[0][0];
      expect(error.code).toBe(AxiosError.ERR_BAD_REQUEST);
    });

    it('assigns ERR_BAD_RESPONSE for a 500 status', () => {
      const resolve = vi.fn();
      const reject = vi.fn();
      settle(resolve, reject, makeResponse(500, () => false));
      const error = reject.mock.calls[0][0];
      expect(error.code).toBe(AxiosError.ERR_BAD_RESPONSE);
    });

    it('assigns ERR_BAD_RESPONSE for a 503 status', () => {
      const resolve = vi.fn();
      const reject = vi.fn();
      settle(resolve, reject, makeResponse(503, () => false));
      const error = reject.mock.calls[0][0];
      expect(error.code).toBe(AxiosError.ERR_BAD_RESPONSE);
    });

    // A custom validateStatus can reject any status — including 1xx, 2xx, 3xx,
    // or ≥ 600 — and the resulting AxiosError must always have a defined code.
    it('assigns ERR_BAD_RESPONSE for a 3xx status rejected via custom validateStatus', () => {
      const resolve = vi.fn();
      const reject = vi.fn();
      settle(resolve, reject, makeResponse(301, () => false));
      const error = reject.mock.calls[0][0];
      expect(error.code).toBeDefined();
      expect(error.code).toBe(AxiosError.ERR_BAD_RESPONSE);
    });

    it('assigns ERR_BAD_RESPONSE for a 2xx status rejected via custom validateStatus', () => {
      const resolve = vi.fn();
      const reject = vi.fn();
      settle(resolve, reject, makeResponse(200, () => false));
      const error = reject.mock.calls[0][0];
      expect(error.code).toBeDefined();
      expect(error.code).toBe(AxiosError.ERR_BAD_RESPONSE);
    });

    it('assigns ERR_BAD_RESPONSE for a 6xx status rejected via custom validateStatus', () => {
      const resolve = vi.fn();
      const reject = vi.fn();
      settle(resolve, reject, makeResponse(600, () => false));
      const error = reject.mock.calls[0][0];
      expect(error.code).toBeDefined();
      expect(error.code).toBe(AxiosError.ERR_BAD_RESPONSE);
    });
  });

  describe('error message', () => {
    it('includes the status code in the error message', () => {
      const resolve = vi.fn();
      const reject = vi.fn();
      settle(resolve, reject, makeResponse(404, () => false));
      const error = reject.mock.calls[0][0];
      expect(error.message).toBe('Request failed with status code 404');
    });
  });
});