fix flakey tests (#3227)

* add tests, escapse strings for console

* add comment about tests in logger.js

* fix undefined prop bug

* fix broken test

* move diff to dependencies

* fix escape function, add more tests, refacter showDiff

* pin diff dependency

* fix flakey timers_spec

* fix another flaky tests, seems .should doesn't retry when chained off of .then 🤔'

* timers_spec fix update, comment

packages/driver/test/cypress/integration/commands/xhr_spec.coffee

@@ -1915,13 +1915,16 @@ describe "src/cy/commands/xhr", ->
             xhr.foo = "bar"
             resolve(xhr)
           xhr.send()
-      .should (xhr) ->
-        ## ensure this is set to prevent accidental
-        ## race conditions down the road if something
-        ## goes wrong
-        expect(xhr.foo).to.eq("bar")
-        expect(xhr.aborted).not.to.be.true
-        expect(log.get("state")).to.eq("passed")
+      .then (xhr) ->
+        cy
+        .wrap(null)
+        .should ->
+          ## ensure this is set to prevent accidental
+          ## race conditions down the road if something
+          ## goes wrong
+          expect(xhr.foo).to.eq("bar")
+          expect(xhr.aborted).not.to.be.true
+          expect(log.get("state")).to.eq("passed")
 
   context "Cypress.on(window:unload)", ->
     it "aborts all open XHR's", ->

packages/driver/test/cypress/integration/cy/timers_spec.js

@@ -387,12 +387,17 @@ describe('driver/src/cy/timers', () => {
     .then((win) => {
       const stub1 = cy.stub()
 
-      win.setTimeout(stub1, 200)
+      // we're setting setTimeout to 500ms because
+      // there were times where the driver's webserver
+      // was sending bytes after 200ms (TTFB) that caused
+      // this test to be flaky.
+      win.setTimeout(stub1, 500)
 
+      // force the window to sync reload
       win.location.reload()
 
       cy
-      .wait(400)
+      .wait(800)
       .then(() => {
         expect(stub1).not.to.be.called
       })