Fixes flaky test in rerun_spec.coffee.

packages/driver/test/cypress/integration/e2e/rerun_spec.js

@@ -0,0 +1,46 @@
+// NOTE: we could clean up this test a lot
+// by probably using preserve:run:state event
+// or by using localstorage
+
+// store these on our outer top window
+// so they are globally preserved
+if (window.top.hasRunOnce == null) {
+  window.top.hasRunOnce = false
+}
+
+if (window.top.previousHash == null) {
+  window.top.previousHash = window.top.location.hash
+}
+
+const isTextTerminal = Cypress.config('isTextTerminal')
+
+describe('rerun state bugs', () => {
+  // NOTE: there's probably other ways to cause a re-run
+  // event more programatically (like firing it through Cypress)
+  // but we get the hashchange coverage for free on this.
+  it('stores viewport globally and does not hang on re-runs', () => {
+    cy.viewport(500, 500).then(() => {
+      if (!window.top.hasRunOnce) {
+        // turn off mocha events for a second
+        Cypress.config('isTextTerminal', false)
+
+        // 1st time around
+        window.top.hasRunOnce = true
+
+        // cause a rerun event to occur
+        // by changing the hash
+        let { hash } = window.top.location
+
+        window.top.location.hash = `${hash}?rerun`
+      } else {
+        if (window.top.location.hash === window.top.previousHash) {
+          // 3rd time around
+          // let the mocha end events fire if they're supposed to
+          Cypress.config('isTextTerminal', isTextTerminal)
+        }
+
+        window.top.location.hash = window.top.previousHash
+      }
+    })
+  })
+})