assert.calledWithExactly(spyOrSpyCall, arg1, arg2, ...);

Passes, when the fake, spy or stub was called with exactly the provided arguments.

It's possible to assert on a dedicated spyCall: sinon.assert.calledWithExactly(call, arg1, arg2, ...);.

import * as sinon from "sinon";
const fake = sinon.fake();

sinon.assert.calledWithExactly(fake, "apple pie");
// => Uncaught Error [AssertError]: expected fake to be called with exact arguments

fake("apple pie");

// Generates no error
sinon.assert.calledWithExactly(fake, "apple pie");

sinon.assert.calledWithExactly(fake, "lemon meringue pie");
// => Uncaught Error [AssertError]: expected fake to be called with exact arguments
// => '"apple pie"' '"lemon meringue pie"'

// reset the history of everything
sinon.resetHistory();

sinon.assert.calledWithExactly(fake, "apple pie");
// => Uncaught Error [AssertError]: expected fake to be called with exact arguments

Asserting on a spyCall

import * as sinon from "sinon";
const fake = sinon.fake();

fake("apple pie");

// get a spyCall instance
const call = fake.firstCall;

// Generates no error
sinon.assert.calledWithExactly(call, "apple pie");

Example using test framework

import tap from "tap";
import * as sinon from "sinon";

tap.test("assert.calledWithExactly - passes with exact arguments", (t) => {
  const fake = sinon.fake();
  fake("apple", "pie");

  t.doesNotThrow(() => {
    sinon.assert.calledWithExactly(fake, "apple", "pie");
  }, "assertion should pass with exact arguments");

  t.end();
});

tap.test("assert.calledWithExactly - fails with extra arguments", (t) => {
  const fake = sinon.fake();
  fake("apple", "pie", "ice cream");

  t.throws(
    () => sinon.assert.calledWithExactly(fake, "apple", "pie"),
    /expected fake to be called with exact arguments/,
    "assertion should fail when extra arguments present"
  );

  t.end();
});

tap.test("assert.calledWithExactly - fails with missing arguments", (t) => {
  const fake = sinon.fake();
  fake("apple");

  t.throws(
    () => sinon.assert.calledWithExactly(fake, "apple", "pie"),
    /expected fake to be called with exact arguments/,
    "assertion should fail when arguments missing"
  );

  t.end();
});