spy.calledWith

Returns true, when the fake, spy or stub was called at least once with the provided arguments.

Can be used for partial matching, Sinon only checks the provided arguments against actual arguments, so a call that received the provided arguments (in the same spots) and possibly others as well will return true.

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

t.test("spy.calledWith checks if spy was called with arguments", (t) => {
  const spy = sinon.spy();

  // False before any calls
  t.equal(
    spy.calledWith("apple pie"),
    false,
    "should be false before any calls"
  );

  // True after calling with the argument
  spy("apple pie");
  t.equal(
    spy.calledWith("apple pie"),
    true,
    "should be true after calling with 'apple pie'"
  );

  // False for arguments that were never used
  t.equal(
    spy.calledWith("lemon meringue pie"),
    false,
    "should be false for unused arguments"
  );

  // Reset history
  sinon.resetHistory();

  // False after reset
  t.equal(
    spy.calledWith("apple pie"),
    false,
    "should be false after resetHistory"
  );

  t.end();
});

Resetting calledWith to default

You can reset calledWith in three different ways:

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