Expectations

All the expectation methods return an expectation instance, meaning you can chain them.

Typical usage:

import t from "tap";
import sinon from "sinon";

t.test("mock expectations can chain atLeast and atMost", (t) => {
  // Create an object with a real method
  const obj = {
    ajax: function () {
      return "response";
    }
  };

  // Set up expectations
  const mock = sinon.mock(obj);
  mock.expects("ajax").atLeast(2).atMost(5);

  // Call the method within the expected range (3 times)
  obj.ajax();
  obj.ajax();
  obj.ajax();

  // Verify expectations are met
  t.doesNotThrow(() => {
    mock.verify();
  }, "should not throw when expectations are met");

  // Restore
  mock.restore();

  t.end();
});

var expectation = sinon.expectation.create([methodName]);

Creates an expectation without a mock object, which is essentially an anonymous mock function.

Method name is optional and is used in exception messages to make them more readable.

var expectation = sinon.mock([methodName]);

The same as the above.

expectation.atLeast(number);

Specify the minimum amount of calls expected.

expectation.atMost(number);

Specify the maximum amount of calls expected.

expectation.never();

Expect the method to never be called.

expectation.once();

Expect the method to be called exactly once.

expectation.twice();

Expect the method to be called exactly twice.

expectation.thrice();

Expect the method to be called exactly thrice.

expectation.exactly(number);

Expect the method to be called exactly number times.

expectation.withArgs(arg1, arg2, ...);

Expect the method to be called with the provided arguments and possibly others.

An expectation instance only holds onto a single set of arguments specified with withArgs. Subsequent calls will overwrite the previously-specified set of arguments (even if they are different), so it is generally not intended that this method be invoked more than once per test case.

expectation.withExactArgs(arg1, arg2, ...);

Expect the method to be called with the provided arguments and no others.

An expectation instance only holds onto a single set of arguments specified with withExactArgs. Subsequent calls will overwrite the previously-specified set of arguments (even if they are different), so it is generally not intended that this method be invoked more than once per test case.

expectation.on(obj);

Expect the method to be called with obj as this."}

expectation.verify();

Verifies the expectation and throws an exception if it's not met.