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--- development:testing:sinonjs:start [2019/01/13 12:36] – created don.lee
+++ development:testing:sinonjs:start [2019/01/13 13:05] (current) – don.lee
@@ Line 1: / Line 1: @@
 ====== Sinon JS ======
+If your test will also involve other 3rd party library, etc. multer. You better also check their own test cases for reference. e.g. https://github.com/expressjs/multer/tree/master/test
+===== Reference =====
+  * https://sinonjs.org/
   * https://semaphoreci.com/community/tutorials/best-practices-for-spies-stubs-and-mocks-in-sinon-js
   * https://codeutopia.net/blog/2016/05/23/sinon-js-quick-tip-how-to-stubmock-complex-objects-such-as-dom-objects/
@@ Line 7: / Line 11: @@
 ===== Spy =====
-Check if a method is called
+  * Check if a method is called
 <code>
@@ Line 16: / Line 20: @@
 </code>
+===== Stub =====
+  * Replace existing method with stub to avoid actually execute the method
+==== Method 1 ====
+  * define a fake function so that it will call that fake one when call
+<code>
+function fake() {  // a fake function to be called
+}
+const stub = sinon.stub(object, 'method').callFakes(fake) // you could also replace the fake with another real function
+...
+stub.restore() // remove stub
+expect(stub.callCount).to.be.eql(n) // check if the method is call n times
+</code>
+==== Method 2 ====
+  * define a return value no matter how you call the stub
+<code>
+const stub = sinon.stub(object, 'method').returns(val) // always return same val
+...
+const test = stub()
+expect(test).to.be.eql(val)
+stub.restore() // remove stub
+expect(stub.callCount).to.be.eql(n) // check if the method is call n times
+</code>
+==== Method 3 ====
+  * resolve a promise with same value no matter how you call the stub
+<code>
+const stub = sinon.stub(object, 'method').resolve(val) // always resolve same val
+...
+const test = await stub()
+expect(test).to.be.eql(val)
+stub.restore() // remove stub
+expect(stub.callCount).to.be.eql(n) // check if the method is call n times
+</code>