test: migrate yarn modern examples to corepack (#1350)

* test: migrate yarn modern examples to corepack

* chore: use corepack for yarn modern maintenance

Author: MikeMcC399

.github/workflows/example-yarn-modern-pnp.yml

@@ -13,7 +13,7 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-
+      - run: corepack enable yarn # experimental - see https://nodejs.org/docs/latest/api/corepack.html
       - name: Custom Yarn command
         uses: ./
         with:

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

@@ -13,7 +13,7 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
-
+      - run: corepack enable yarn # experimental - see https://nodejs.org/docs/latest/api/corepack.html
       - name: Custom Yarn command
         uses: ./
         with:

docs/MAINTENANCE.md

@@ -6,7 +6,7 @@ This document describes updating the [examples](../examples) in this repository
 
 The [examples](../examples) directory contains examples of the use of Cypress (Current) [Configuration](https://docs.cypress.io/guides/references/configuration) which applies to Cypress 10 and later. These examples test and demonstrate the use of [cypress-io/github-action](https://github.com/cypress-io/github-action).
 
-The examples make use of [npm](https://www.npmjs.com/), [pnpm](https://pnpm.io/), [Yarn 1 (Classic)](https://classic.yarnpkg.com/) and [Yarn Modern](https://yarnpkg.com/) (Yarn 2 and later) to define and install the packages being used.
+The examples make use of [npm](https://www.npmjs.com/), [pnpm](https://pnpm.io/), [Yarn 1 (Classic)](https://classic.yarnpkg.com/) and [Yarn Modern](https://yarnpkg.com/) to define and install the packages being used. For [Yarn Modern](https://yarnpkg.com/) the recommended [Corepack](https://yarnpkg.com/corepack) is used as a Yarn version manager.
 
 *The previous [examples/v9](https://github.com/cypress-io/github-action/tree/v5/examples/v9) are archived in the [v5](https://github.com/cypress-io/github-action/tree/v5/) branch. This directory contains examples which were set up to use Cypress `9.7.0`, the last version using Legacy Configuration, covering Cypress 9 and below. These `v9` examples are no longer maintained.
 
@@ -18,20 +18,16 @@ The examples make use of [npm](https://www.npmjs.com/), [pnpm](https://pnpm.io/)
 
 - [git](https://git-scm.com/) distributed version control system.
 
-- [npm](https://www.npmjs.com/), which is installed with [Node.js](https://nodejs.org/)
+- [npm](https://www.npmjs.com/), which is installed with [Node.js](https://nodejs.org/).
+
+- [corepack](https://github.com/nodejs/corepack), which is installed with [Node.js](https://nodejs.org/).
 
 - [pnpm](https://pnpm.io/) installed through:
 
 ```bash
 npm install pnpm@latest -g
 ```
 
-- [Yarn 1 (Classic)](https://classic.yarnpkg.com/) installed through:
-
-```bash
-npm install yarn@latest -g
-```
-
 - [Visual Studio Code](https://code.visualstudio.com/) or other editor
 
 Under Microsoft Windows it may be necessary to also execute the following preparatory command:
@@ -55,3 +51,7 @@ This updates all [examples](../examples) to cypress@latest.
 [.github/workflows/example-install-only.yml](../.github/workflows/example-install-only.yml) contains a hard-coded Cypress version number. This can be updated by hand.
 
 After updating the examples locally, they can be committed with git and a pull request opened on GitHub.
+
+### Updating Yarn examples
+
+The script [/scripts/update-cypress-latest-yarn.sh](../scripts/update-cypress-latest-yarn.sh) (which is invoked through `npm run update:cypress` to update the Yarn examples) runs [Yarn 1 (Classic)](https://classic.yarnpkg.com/) as an `npm` global install, runs [Yarn Modern](https://yarnpkg.com/) through Corepack and returns Corepack to its default disabled state on completion.

examples/yarn-modern-pnp/.yarn/releases/yarn-4.6.0.cjs

@@ -1,3 +1,11 @@
 # example: yarn-modern-pnp
 
-This example demonstrates installing dependencies using [Yarn Modern (version 2 and later)](https://yarnpkg.com/) with [Plug'n'Play](https://yarnpkg.com/features/pnp) turned on.
+This example demonstrates installing dependencies using [Yarn Modern v4](https://yarnpkg.com/) with [corepack](https://yarnpkg.com/corepack) enabled and the default configuration of [Plug'n'Play](https://yarnpkg.com/features/pnp) enabled.
+
+Run locally with:
+
+```shell
+corepack enable yarn
+yarn
+yarn test
+```

examples/yarn-modern-pnp/.yarnrc.yml

@@ -1,3 +1 @@
 nodeLinker: node-modules
-
-yarnPath: .yarn/releases/yarn-4.6.0.cjs

examples/yarn-modern-pnp/README.md

@@ -1,3 +1,11 @@
 # example: yarn-modern
 
-This example demonstrates installing dependencies using [Yarn Modern (version 2 and later)](https://yarnpkg.com/).
+This example demonstrates installing dependencies using [Yarn Modern v4](https://yarnpkg.com/) with [corepack](https://yarnpkg.com/corepack) enabled and the configuration option `nodeLinker: node-modules` selected.
+
+Run locally with:
+
+```shell
+corepack enable yarn
+yarn
+yarn test
+```

examples/yarn-modern/.yarn/releases/yarn-4.6.0.cjs

@@ -1,14 +1,31 @@
 #!/bin/bash
 set -e # fail on error
 #
+if ! command -v corepack &> /dev/null
+then
+    echo "**corepack is required and not installed**"
+    echo "Refer to Yarn Modern installation instructions"
+    echo "https://yarnpkg.com/getting-started/install"
+    echo "https://yarnpkg.com/corepack"
+    echo
+exit 1 # failure
+else
+    echo "corepack is installed"
+fi
+#
 # Examples using the yarn package manager are
 # updated to Cypress latest version
 #
-# Make sure that yarn is installed
-./scripts/check-package-manager-yarn.sh
-
+# After running this script, Yarn 1 Classic latest is installed
+# corepack is disabled
+#
 echo updating yarn examples to Cypress latest version
 cd examples
+# --------------------------------------------------
+# Yarn 1 Classic section
+# No corepack
+corepack disable yarn
+npm install yarn@latest -g
 
 # examples/start-and-yarn-workspaces (yarn)
 echo
@@ -37,6 +54,11 @@ cd yarn-classic
 yarn add cypress --dev --exact
 cd ..
 
+# --------------------------------------------------
+# Yarn 4 Modern section
+# Use corepack
+corepack enable yarn
+
 # examples/yarn-modern
 echo
 echo updating examples/yarn-modern to cypress@latest
@@ -53,4 +75,10 @@ yarn set version latest
 yarn add cypress --dev --exact
 cd ..
 
+corepack disable yarn
+echo "corepack is now disabled for Yarn"
+npm install yarn@latest -g
+# End of Yarn 4 Modern section
+# --------------------------------------------------
+
 cd ..

examples/yarn-modern/.yarnrc.yml

@@ -4,14 +4,12 @@ set -e # fail on error
 # All examples are updated to Cypress latest version
 #
 # Make sure that Node.js LTS from https://nodejs.org/en/ is installed before running.
-# Ensure yarn v1 (classic) and pnpm are installed.
-# npm install yarn -g
+# Ensure pnpm is installed.
 # npm install pnpm -g
 # The VScode editor is also used in the last step if available.
 #
 # First check if the required package managers are installed
 ./scripts/check-package-manager-npm.sh
-./scripts/check-package-manager-yarn.sh
 ./scripts/check-package-manager-pnpm.sh
 # then proceed to updating the examples
 echo