Fix testConfigOverrides not affecting viewport (#8006)

packages/driver/cypress/integration/e2e/testConfigOverrides.spec.js

@@ -326,6 +326,25 @@ describe('per-test config', () => {
   })
 })
 
+describe('viewport', () => {
+  // https://github.com/cypress-io/cypress/issues/7631
+  it('can set viewport in testConfigOverrides', { viewportWidth: 200, viewportHeight: 100 }, () => {
+    cy.visit('/fixtures/generic.html')
+    cy.window().then((win) => {
+      expect(win.innerWidth).eq(200)
+      expect(win.innerHeight).eq(100)
+    })
+  })
+
+  it('viewport does not leak between tests', () => {
+    cy.visit('/fixtures/generic.html')
+    cy.window().then((win) => {
+      expect(win.innerWidth).eq(1000)
+      expect(win.innerHeight).eq(660)
+    })
+  })
+})
+
 describe('testConfigOverrides baseUrl @slow', () => {
   it('visit 1', { baseUrl: 'http://localhost:3501' }, () => {
     cy.visit('/fixtures/generic.html')

packages/driver/src/cy/commands/window.js

@@ -29,8 +29,8 @@ const validOrientations = ['landscape', 'portrait']
 // refresh would cause viewport to hang
 let currentViewport = null
 
-module.exports = (Commands, Cypress, cy, state, config) => {
-  const defaultViewport = _.pick(config(), 'viewportWidth', 'viewportHeight')
+module.exports = (Commands, Cypress, cy, state) => {
+  const defaultViewport = _.pick(Cypress.config(), 'viewportWidth', 'viewportHeight')
 
   // currentViewport could already be set due to previous runs
   currentViewport = currentViewport || defaultViewport
@@ -41,7 +41,9 @@ module.exports = (Commands, Cypress, cy, state, config) => {
     // need to restore prior to running the next test
     // after which we simply null and wait for the
     // next viewport change
-    setViewportAndSynchronize(defaultViewport.viewportWidth, defaultViewport.viewportHeight)
+    const configDefaultViewport = _.pick(Cypress.config(), 'viewportWidth', 'viewportHeight')
+
+    setViewportAndSynchronize(configDefaultViewport.viewportWidth, configDefaultViewport.viewportHeight)
   })
 
   const setViewportAndSynchronize = (width, height) => {