BE-SPAN/node_modules/shimmer/test/unwrap.tap.js

'use strict';

var tap     = require('tap')
  , test    = tap.test
  , sinon   = require('sinon')
  , shimmer = require('../index.js')
  ;

var outsider = 0;
function counter() { return ++outsider; }

var generator = {
  inc : counter
};

test("should unwrap safely", function (t) {
  t.plan(9);

  t.equal(counter, generator.inc, "basic function equality testing should work");
  t.doesNotThrow(function () { generator.inc(); });
  t.equal(1, outsider, "calls have side effects");

  function wrapper(original) {
    return function () {
      return original.apply(this, arguments);
    };
  }
  shimmer.wrap(generator, 'inc', wrapper);

  t.doesNotEqual(counter, generator.inc, "function should be wrapped");

  t.doesNotThrow(function () { generator.inc(); });
  t.equal(2, outsider, "original function has still been called");

  shimmer.unwrap(generator, 'inc');
  t.equal(counter, generator.inc, "basic function equality testing should work");
  t.doesNotThrow(function () { generator.inc(); });
  t.equal(3, outsider, "original function has still been called");
});

test("shouldn't throw on double unwrapping", function (t) {
  t.plan(6);

  t.equal(counter, generator.inc, "basic function equality testing should work");

  var mock = sinon.expectation
                  .create('logger')
                  .withArgs("no original to unwrap to -- " +
                            "has inc already been unwrapped?")
                  .once();
  shimmer({logger : mock});

  function wrapper(original) {
    return function () {
      return original.apply(this, arguments);
    };
  }
  shimmer.wrap(generator, 'inc', wrapper);

  t.doesNotEqual(counter, generator.inc, "function should be wrapped");

  shimmer.unwrap(generator, 'inc');
  t.equal(counter, generator.inc, "basic function equality testing should work");

  t.doesNotThrow(function () { shimmer.unwrap(generator, 'inc'); },
                "should double unwrap without issue");
  t.equal(counter, generator.inc, "function is unchanged after unwrapping");

  t.doesNotThrow(function () {
    mock.verify();
  }, "logger was called with the expected message");
});

test("unwrap called with no arguments", function (t) {
  t.plan(2);

  var mock = sinon.expectation
                  .create('logger')
                  .twice();
  shimmer({logger : mock});

  t.doesNotThrow(function () { shimmer.unwrap(); }, "should log instead of throwing");

  t.doesNotThrow(function () {
    mock.verify();
  }, "logger was called with the expected message");
});

test("unwrap called with module but no name", function (t) {
  t.plan(2);

  var mock = sinon.expectation
                  .create('logger')
                  .twice();
  shimmer({logger : mock});

  t.doesNotThrow(function () { shimmer.unwrap({}); }, "should log instead of throwing");

  t.doesNotThrow(function () {
    mock.verify();
  }, "logger was called with the expected message");
});