Update cypress.md

Author: basarat

docs/testing/cypress.md

@@ -270,7 +270,7 @@ cy.get('#foo')
 This keeps you from having to constantly add arbitrary timeout (and retry) logic in your test code flow. 
 
 
-## Tip: Unit testing applicaiton code
+## Tip: Unit testing application code
 You can also use cypress to unit test your application code in isolation e.g.
 
 ```js
@@ -286,6 +286,15 @@ it('should only call function once', () => {
 });
 ```
 
+## Tip: Breakpoint
+The automatic snapshots + command log generated by the cypress test are great for debugging. That said you can pause test execution in two ways. 
+
+First make sure you have chrome developer tools open in the test runner. `CMD + ALT + i` on mac / `F12` on windows.
+
+* Application code breakpoints: Use a `debugger` statement in your application code and the test runner will stop on that just like standard web developement. 
+* Test code breakpoints: You can use the `.debug()` command and cypress test execution will stop at it. Alternatively you can use a `debugger` statement in a `.then` command callback to cause a pause. e.g `.then(() => { debugger })`. You can even use it to grab some element `cy.get('#foo').then(($ /* a reference to the dom element */) => { debugger; })` or a network call e.g. `cy.request('https://someurl').then((res /* network response */) => { debugger });`.
+
+
 
 ## Resources 
 * Website: https://www.cypress.io/