test: deflake headless system-test on webkit (appData ensureDir/symlink race) (#33812)

packages/server/lib/util/app_data.js

@@ -114,14 +114,12 @@ module.exports = {
   },
 
   ensure () {
+    // ensureSymlinkAsync lstats its src, so the appData dir must exist
+    // before symlink() runs — these can't be parallelized.
     const ensure = () => {
       return this.removeSymlink()
-      .then(() => {
-        return Promise.join(
-          fs.ensureDirAsync(this.path()),
-          !isProduction() ? this.symlink() : undefined,
-        )
-      })
+      .then(() => fs.ensureDirAsync(this.path()))
+      .then(() => (!isProduction() ? this.symlink() : undefined))
     }
 
     // try twice to ensure the dir

packages/server/test/unit/util/app_data_spec.js

@@ -2,7 +2,9 @@ require('../../spec_helper')
 const os = require('os')
 const osPath = require('ospath')
 const path = require('path')
+const Promise = require('bluebird')
 
+const { fs } = require('../../../lib/util/fs')
 const AppData = require(`../../../lib/util/app_data`)
 
 describe('lib/util/app_data', () => {
@@ -31,6 +33,30 @@ describe('lib/util/app_data', () => {
     })
   })
 
+  context('#ensure', () => {
+    it('does not create the symlink until the appData directory exists', async () => {
+      let ensureDirCompleted = false
+      let ensureDirCompletedAtSymlinkCall = null
+
+      sinon.stub(fs, 'removeAsync').resolves()
+      sinon.stub(fs, 'ensureDirAsync').callsFake(() => {
+        return Promise.delay(50).then(() => {
+          ensureDirCompleted = true
+        })
+      })
+
+      sinon.stub(fs, 'ensureSymlinkAsync').callsFake(() => {
+        ensureDirCompletedAtSymlinkCall = ensureDirCompleted
+
+        return Promise.resolve()
+      })
+
+      await AppData.ensure()
+
+      expect(ensureDirCompletedAtSymlinkCall, 'ensureSymlinkAsync was called before the appData directory existed').to.be.true
+    })
+  })
+
   context('#findCommonAncestor', () => {
     it('posix', () => {
       expect(AppData.findCommonAncestor('/a/b/c/d', '/a/b/c/d/')).to.equal('/a/b/c/d')

system-tests/__snapshots__/headless_spec.ts.js

@@ -1,59 +1,3 @@
-exports['e2e headless / tests in headless mode pass'] = `
-
-====================================================================================================
-
-  (Run Starting)
-
-  ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
-  │ Cypress:    1.2.3                                                                              │
-  │ Browser:    FooBrowser 88                                                                      │
-  │ Specs:      1 found (headless.cy.js)                                                           │
-  │ Searched:   cypress/e2e/headless.cy.js                                                         │
-  └────────────────────────────────────────────────────────────────────────────────────────────────┘
-
-
-────────────────────────────────────────────────────────────────────────────────────────────────────
-                                                                                                    
-  Running:  headless.cy.js                                                                  (1 of 1)
-
-
-  e2e headless spec
-    ✓ has the expected values for Cypress.browser
-    ✓ has expected launch args
-
-
-  2 passing
-
-
-  (Results)
-
-  ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
-  │ Tests:        2                                                                                │
-  │ Passing:      2                                                                                │
-  │ Failing:      0                                                                                │
-  │ Pending:      0                                                                                │
-  │ Skipped:      0                                                                                │
-  │ Screenshots:  0                                                                                │
-  │ Video:        false                                                                            │
-  │ Duration:     X seconds                                                                        │
-  │ Spec Ran:     headless.cy.js                                                                   │
-  └────────────────────────────────────────────────────────────────────────────────────────────────┘
-
-
-====================================================================================================
-
-  (Run Finished)
-
-
-       Spec                                              Tests  Passing  Failing  Pending  Skipped  
-  ┌────────────────────────────────────────────────────────────────────────────────────────────────┐
-  │ ✔  headless.cy.js                           XX:XX        2        2        -        -        - │
-  └────────────────────────────────────────────────────────────────────────────────────────────────┘
-    ✔  All specs passed!                        XX:XX        2        2        -        -        -  
-
-
-`
-
 exports['e2e headless / tests in headed mode pass in !electron'] = `
 
 ====================================================================================================

system-tests/test/headless_spec.ts

@@ -51,7 +51,6 @@ describe('e2e headless', function () {
       },
     },
     headed: false,
-    snapshot: true,
   })
 
   // NOTE: cypress run --headed