assert.alwaysCalledWith(spy, arg1, arg2, ...);

Passes when the fake, spy or stub has always been called with the provided arguments.

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

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

fake("apple pie", "cherry pie");

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

fake("lemon meringue pie");
sinon.assert.alwaysCalledWith(fake, "apple pie");
// => Uncaught Error [AssertError]: expected fake to always be called with arguments
// => Call 1:
// => '"apple pie"'
// => '"cherry pie"'
// => Call 2:
// => '"lemon meringue pie"' '"apple pie"'

If you want to assert that the fake was always called with exactly the specified arguments, use sinon.assert.alwaysCalledWithExactly

Example using test framework

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

tap.test(
  "assert.alwaysCalledWith - passes when all calls have arguments",
  (t) => {
    const fake = sinon.fake();
    fake("apple");
    fake("apple", "pie");
    fake("apple", "pie", "ice cream");

    t.doesNotThrow(() => {
      sinon.assert.alwaysCalledWith(fake, "apple");
    }, "assertion should pass when all calls include argument");

    t.end();
  }
);

tap.test(
  "assert.alwaysCalledWith - fails when one call lacks arguments",
  (t) => {
    const fake = sinon.fake();
    fake("apple");
    fake("banana");

    t.throws(
      () => sinon.assert.alwaysCalledWith(fake, "apple"),
      /expected fake to always be called with arguments/,
      "assertion should fail when not all calls include argument"
    );

    t.end();
  }
);