TypeError: 'undefined' is not a function (evaluating 'sinon.spy()')

Question

I'm trying to use sinon.js in testing of a backbone application. But unfortunately I cannot use spy method due to error:

TypeError: 'undefined' is not a function (evaluating 'sinon.spy()')

Here is the steps to reproduce the error:

1. Create an empty project with backbone yeoman generator
2. Install sinon: cd test && bower install sinon
3. Include in test/index.html <script src="bower_components/sinon/lib/sinon.js"></script>

4. Create spy in test/spec/test.js:

   describe('Give it some context', function () {
       describe('maybe a bit more context here', function () {
           it('should run here few assertions', function () {
             var spy = sinon.spy();
             spy.should.be.ok;
           });
       });
   });
   

5. Run the test with grunt: grunt test

6. The test will fail with a described error.

Could anyone help to find out what is wrong?

Answer 1

I'll just leave here the list of files that sinon conveniently forgets to load if it is loaded as a <script> or with require.js (as AMD module) - basically anything else than in node.js:

"sinon/lib/sinon.js",
"sinon/lib/sinon/spy.js",
"sinon/lib/sinon/call.js",
"sinon/lib/sinon/behavior.js",
"sinon/lib/sinon/stub.js",
"sinon/lib/sinon/mock.js",
"sinon/lib/sinon/collection.js",
"sinon/lib/sinon/assert.js",
"sinon/lib/sinon/sandbox.js",
"sinon/lib/sinon/test.js",
"sinon/lib/sinon/test_case.js",
"sinon/lib/sinon/match.js"

Feel free to skip any of those but expect sinon to fail in curious ways.

Answer 2

It turned out that such functionality as spies, stubs, etc should be added manually by including scripts from lib/sinon folder. This fact is mentioned in Installation section. And due to the code of the core sinon.js file only in Node.js environment it is done automatically.

Answer 3

I encountered the same problem with sinon 1.17.2 and Chrome 47.0. After trying the above solutions and variations of those, I ended up using the nuclear option and switching to Jasmine.

For my test suite, it only took about 15 minutes of some global find-and-replace to convert my chai 'expects' into Jasmine ones and some differences around mocha before syntax; Jasmine flagged the unexpected syntax clearly. Jasmine spy objects were a fine substitute for sinon.