tests: Frontend test Windows ZIP (#4894)

* tests:  Frontend test Windows ZIP

This PR introduces Frontend testing within Github actions!

We're depending a lot on saucelabs recently and that's fine but sometimes we just want to quickly do a frontend simple test on a weird environment (IE windows build) so this PR solves that problem.

Things to note.

    It still builds the windows .zip if the cypress tests fail.
    It does not add any heavy deps to Etherpad as cypress must be installed in CI.
    Cypress is responsible for running the Etherpad instance.

It's up to us how much we use this or not, I know it introduces a bunch of technical debt but I tried to keep that a minimum by compartmentalizing things and documenting where required.

* Update .github/workflows/windows-zip.yml

Co-authored-by: Richard Hansen <rhansen@rhansen.org>

* remove timeouts

* Move folder structure up a level

* Update windows-zip.yml

* Update test.js

Co-authored-by: Richard Hansen <rhansen@rhansen.org>

.github/workflows/windows-zip.yml

@@ -65,11 +65,13 @@ jobs:
     - name: Extract Etherpad
       run: 7z x etherpad-lite-win.zip -oetherpad
 
-    - name: list
+    - name: Install Cypress
-      run: dir etherpad
+      run: npm install cypress -g
 
     - name: Run Etherpad
       run: |
             cd etherpad
             node node_modules\ep_etherpad-lite\node\server.js &
             curl --connect-timeout 10 --max-time 20 --retry 5 --retry-delay 10 --retry-max-time 60 --retry-connrefused http://127.0.0.1:9001/p/test
+            cd src\tests\frontend
+            cypress run --spec cypress\integration\test.js --config-file cypress\cypress.json

src/tests/frontend/cypress/.gitignore

@@ -0,0 +1,5 @@
+fixtures/*
+plugins/*
+support/*
+videos/*
+screenshots/*

src/tests/frontend/cypress/README.md

@@ -0,0 +1,10 @@
+# Cypress Etherpad guide
+We don't install Etherpad as a dev dep or dep within Etherpad because it's not
+our core Frontend testing tool
+
+## Quick start
+```
+npm i -g cypress
+cd src/tests/frontend/cypress/
+cypress open
+```

src/tests/frontend/cypress/cypress.json

@@ -0,0 +1,3 @@
+{
+  "baseUrl": "http://127.0.0.1:9001"
+}

src/tests/frontend/cypress/integration/test.js

@@ -0,0 +1,22 @@
+'use strict';
+
+Cypress.Commands.add('iframe', {prevSubject: 'element'},
+    ($iframe) => new Cypress.Promise((resolve) => {
+      $iframe.ready(() => {
+        resolve($iframe.contents().find('body'));
+      });
+    }));
+
+describe(__filename, () => {
+  it('Pad content exists', async () => {
+    cy.visit('http://127.0.0.1:9001/p/test');
+    cy.get('iframe[name="ace_outer"]', {timeout: 10000}).iframe()
+        .find('.line-number:first')
+        .should('have.text', '1');
+    cy.get('iframe[name="ace_outer"]').iframe()
+        .find('iframe[name="ace_inner"]').iframe()
+        .find('.ace-line:first')
+        .should('be.visible')
+        .should('have.text', 'Welcome to Etherpad!');
+  });
+});