"use strict"; const {strict: assert} = require("assert"); // Stubs don't do any magical modifications to your namespace. They // just provide you a function that records what arguments get passed // to it. To use stubs as something more like "spies," use something // like set_global() to override your namespace. exports.make_stub = function () { const self = {}; self.num_calls = 0; self.f = function (...args) { self.last_call_args = args; self.num_calls += 1; return true; }; self.get_args = function (...param_names) { const result = {}; for (const [i, name] of param_names.entries()) { result[name] = self.last_call_args[i]; } return result; }; return self; }; (function test_ourselves() { const stub = exports.make_stub(); stub.f("blue", 42); assert.equal(stub.num_calls, 1); const args = stub.get_args("color", "n"); assert.equal(args.color, "blue"); assert.equal(args.n, 42); })();