feat: add yarn 1 (classic) examples

.github/workflows/example-yarn-classic.yml

@@ -0,0 +1,35 @@
+name: example-yarn-classic
+on:
+  push:
+    branches:
+      - 'master'
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+
+  # ~~~~~~~~~~~~~~~~~~ Cypress v9 and below (using Legacy configuration) ~~~~~~~~~~~~~~~~~~~ #
+
+  yarn-classic-v9:
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Test with Yarn Classic
+        uses: ./
+        with:
+          working-directory: examples/v9/yarn-classic
+
+# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Cypress v10 and higher ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #
+
+  yarn-classic:
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+
+      - name: Test with Yarn Classic
+        uses: ./
+        with:
+          working-directory: examples/yarn-classic

.gitignore

@@ -4,3 +4,21 @@ examples/**/cypress/screenshots
 examples/**/cypress/downloads
 results.json
 .vscode/
+
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# For Yarn Classic and Yarn Modern without Zero-Installs
+# see https://yarnpkg.com/getting-started/qa/#which-files-should-be-gitignored
+
+examples/**/.pnp.*
+examples/**/.yarn/*
+!examples/**/.yarn/patches
+!examples/**/.yarn/plugins
+!examples/**/.yarn/releases
+!examples/**/.yarn/sdks
+!examples/**/.yarn/versions

README.md

@@ -35,6 +35,8 @@
 - pass [custom build id](#custom-build-id) when recording to Cypress Cloud
 - generate a [robust custom build id](#robust-custom-build-id) to allow re-running the workflow
 - use different [working-directory](#working-directory)
+- use [Yarn Classic](#yarn-classic)
+- use [Yarn workspaces](#yarn-workspaces)
 - use [custom cache key](#custom-cache-key)
 - run tests on multiple [Node versions](#node-versions)
 - split [install and tests](#split-install-and-tests) into separate jobs
@@ -993,6 +995,31 @@ jobs:
 
 See [cypress-gh-action-subfolders](https://github.com/bahmutov/cypress-gh-action-subfolders) (legacy) for example.
 
+### Yarn Classic
+
+If a `yarn.lock` file is found, the action uses the [Yarn 1 (Classic)](https://classic.yarnpkg.com/) command `yarn --frozen-lockfile` by default to install dependencies.
+
+```yaml
+name: example-yarn-classic
+on: push
+jobs:
+  yarn-classic:
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Cypress run
+        uses: cypress-io/github-action@v5
+        with:
+          working-directory: examples/yarn-classic
+```
+
+See [example-yarn-classic.yml](.github/workflows/example-yarn-classic.yml) for an example.
+
+[![Yarn classic example](https://github.com/cypress-io/github-action/workflows/example-yarn-classic/badge.svg?branch=master)](.github/workflows/example-yarn-classic.yml)
+
+See below under [Yarn Modern](#yarn-modern) (version 2 and later) for instructions on installing dependencies using this later version.
+
 ### Yarn workspaces
 
 This action should discover the Yarn workspaces correctly. For example, see folder [examples/start-and-yarn-workspaces](examples/start-and-yarn-workspaces) and workflow file [example-start-and-yarn-workspaces.yml](.github/workflows/example-start-and-yarn-workspaces.yml)
@@ -1175,15 +1202,19 @@ See [cypress-gh-action-example](https://github.com/bahmutov/cypress-gh-action-ex
 
 This action installs local dependencies using lock files. If `yarn.lock` file is found, the install uses `yarn --frozen-lockfile` command. Otherwise it expects to find `package-lock.json` and install using `npm ci` command.
 
-The above default `yarn` installation command can be replaced for [Yarn Berry](https://yarnpkg.com/) (Yarn 2 and later) using the `install-command` parameter, for example:
+#### Yarn Modern
+
+The above default `yarn` installation command can be replaced for [Yarn Modern](https://yarnpkg.com/) (Yarn 2 and later) using the `install-command` parameter, for example:
 
 ```yml
 - uses: cypress-io/github-action@v5
   with:
     install-command: yarn install
 ```
 
-This action uses several production dependencies. The minimum Node version required to run this action depends on the minimum Node required by the dependencies.
+#### Minimum Node.js
+
+This action uses several production dependencies. The minimum Node version required to run this action depends on the minimum Node version required by the dependencies.
 
 ## Debugging
 

examples/v9/yarn-classic/README.md

@@ -0,0 +1,3 @@
+# example: yarn-classic
+
+This example demonstrates installing dependencies using [Yarn 1 (Classic)](https://classic.yarnpkg.com/lang/en/).

examples/v9/yarn-classic/cypress.json

@@ -0,0 +1,6 @@
+{
+  "fixturesFolder": false,
+  "supportFile": false,
+  "pluginsFile": false,
+  "baseUrl": "https://example.cypress.io/"
+}

examples/v9/yarn-classic/cypress/integration/spec.js

@@ -0,0 +1,7 @@
+/// <reference types="cypress" />
+describe('example: yarn-classic', () => {
+  it('loads the deployed site', () => {
+    cy.visit('/')
+    cy.contains('h1', 'Kitchen Sink')
+  })
+})

examples/v9/yarn-classic/package.json

@@ -0,0 +1,13 @@
+{
+  "name": "example-yarn-classic",
+  "version": "1.0.0",
+  "description": "Install dependencies using Yarn",
+  "scripts": {
+    "test": "cypress run"
+  },
+  "license": "MIT",
+  "private": true,
+  "devDependencies": {
+    "cypress": "9.7.0"
+  }
+}