capture AUT uncaught errors and properly route them to uncaught… (#5249)

* set global onerror same as autWindow.onerror * cleanup spec * add link to issue * Update uncaught_errors_spec.coffee * fix spec: use throw instead of done cb * fix spec for global onerror * temp 10/30/19 [skip ci] * cleanup * use object.defineproperty to overwrite setter, only set top.onerror once * update snapshot * refactor xhr_spec * fix xhr_spec * refactor address feedback * fix oops * fix rerun mode Co-authored-by: Jennifer Shehane <jennifer@cypress.io>
cypress-io · Oct 30, 2019 · 232c004 · 232c004 · cypress-bot · Oct 30, 2019
1 parent 249db45
commit 232c004
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Showing 6 changed files with 86 additions and 4 deletions.
diff --git a/packages/driver/src/cy/commands/xhr.coffee b/packages/driver/src/cy/commands/xhr.coffee
@@ -183,8 +183,10 @@ startXhrServer = (cy, state, config) ->
       if log = logs[xhr.id]
         log.snapshot("error").error(err)
 
-      if r = state("reject")
-        r(err)
+      ## re-throw the error since this came from AUT code, and needs to
+      ## cause an 'uncaught:exception' event. This error will be caught in
+      ## top.onerror with stack as 5th argument.
+      throw err
 
     onXhrAbort: (xhr, stack) =>
       setResponse(state, xhr)

diff --git a/packages/driver/src/cypress/cy.coffee b/packages/driver/src/cypress/cy.coffee
@@ -52,6 +52,32 @@ setWindowDocumentProps = (contentWindow, state) ->
 setRemoteIframeProps = ($autIframe, state) ->
   state("$autIframe", $autIframe)
 
+
+## We only set top.onerror once since we make it configurable:false
+## but we update cy instance every run (page reload or rerun button)
+curCy = null
+setTopOnError = (cy) ->
+  if curCy
+    curCy = cy
+    return
+
+  curCy = cy
+
+  onTopError = ->
+    curCy.onUncaughtException.apply(curCy, arguments)
+
+  top.onerror = onTopError
+
+  ## Prevent Mocha from setting top.onerror which would override our handler
+  ## Since the setter will change which event handler gets invoked, we make it a noop
+  Object.defineProperty(top, 'onerror', {
+    set: ->
+    get: -> onTopError
+    configurable: false
+    enumerable: true
+  })
+
+
 create = (specWindow, Cypress, Cookies, state, config, log) ->
   stopped = false
   commandFns = {}
@@ -1107,6 +1133,8 @@ create = (specWindow, Cypress, Cookies, state, config, log) ->
           args: obj
         })
     })
+
+  setTopOnError(cy)
 
   ## make cy global in the specWindow
   specWindow.cy = cy

diff --git a/packages/driver/test/cypress/fixtures/global-error.html b/packages/driver/test/cypress/fixtures/global-error.html
@@ -0,0 +1,28 @@
+<!DOCTYPE html>
+<html>
+<head>
+  <meta charset='utf-8'>
+  <meta http-equiv='X-UA-Compatible' content='IE=edge'>
+  <title>Page Title</title>
+  <meta name='viewport' content='width=device-width, initial-scale=1'>
+</head>
+<body>
+  <script>
+    setTimeout(()=>{
+      one()
+    }, 0)
+
+    function one() {
+      two()
+    }
+
+    function two() {
+      three()
+    }
+
+    function three() {
+      foo.bar()      
+    }
+  </script>
+</body>
+</html>
diff --git a/packages/driver/test/cypress/integration/commands/xhr_spec.coffee b/packages/driver/test/cypress/integration/commands/xhr_spec.coffee
@@ -780,13 +780,18 @@ describe "src/cy/commands/xhr", ->
 
       it "sets err on log when caused by code errors", (done) ->
         finalThenCalled = false
+        uncaughtException = cy.stub().returns(true)
+        cy.on 'uncaught:exception', uncaughtException
 
         cy.on "fail", (err) =>
           lastLog = @lastLog
 
           expect(@logs.length).to.eq(1)
           expect(lastLog.get("name")).to.eq("xhr")
-          expect(lastLog.get("error")).to.eq err
+          expect(lastLog.get("error").message).contain('foo is not defined')
+          ## since this is AUT code, we should allow error to be caught in 'uncaught:exception' hook
+          ## https://github.com/cypress-io/cypress/issues/987
+          expect(uncaughtException).calledOnce
           done()
 
         cy

diff --git a/packages/driver/test/cypress/integration/e2e/uncaught_errors_spec.coffee b/packages/driver/test/cypress/integration/e2e/uncaught_errors_spec.coffee
@@ -110,3 +110,14 @@ describe "uncaught errors", ->
         .appendTo(win.document.body)
 
       .contains("visit").click()
+
+  ## https://github.com/cypress-io/cypress/issues/987
+  it 'global onerror', (done) ->
+    cy.once 'uncaught:exception', (err) ->
+      expect(err.stack).contain('foo is not defined')
+      expect(err.stack).contain('one')
+      expect(err.stack).contain('two')
+      expect(err.stack).contain('three')
+      done()
+
+    cy.visit('/fixtures/global-error.html')
diff --git a/packages/server/__snapshots__/3_js_error_handling_spec.coffee.js b/packages/server/__snapshots__/3_js_error_handling_spec.coffee.js
@@ -50,7 +50,15 @@ https://on.cypress.io/uncaught-exception-from-application
       at stack trace line
 
   2) s1 without an afterEach hook t2:
-     ReferenceError: bar is not defined
+     Uncaught ReferenceError: bar is not defined
+
+This error originated from your application code, not from Cypress.
+
+When Cypress detects uncaught errors originating from your application it will automatically fail the current test.
+
+This behavior is configurable, and you can choose to turn this off by listening to the 'uncaught:exception' event.
+
+https://on.cypress.io/uncaught-exception-from-application
       at stack trace line
       at stack trace line
       at stack trace line