spy.exceptions

Array of exception objects thrown, spy.exceptions[0] is the exception thrown by the first call of the fake, spy or stub.

If the call did not throw an error, the value at the call's location in .exceptions will be undefined.

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

t.test("spy.exceptions contains all thrown exceptions", (t) => {
  const error = new TypeError("apple pie");
  const f = sinon.fake.throws(error);

  // Call twice (catching exceptions)
  try {
    f();
  } catch (e) {
    // Expected
  }
  try {
    f();
  } catch (e) {
    // Expected
  }

  // Verify exceptions array
  t.equal(f.exceptions.length, 2, "should have 2 exceptions");
  t.equal(f.exceptions[0], error, "first exception should be the error");
  t.equal(f.exceptions[1], error, "second exception should be the error");
  t.equal(
    f.exceptions[0].message,
    "apple pie",
    "exception message should match"
  );

  t.end();
});

Resetting exceptions to default

You can reset exceptions in three different ways:

• spy.resetHistory
• sinon.resetHistory
• sinon.reset