From e8b3db419d4d8ad959c3b260d873b90bf8a2cbec Mon Sep 17 00:00:00 2001
From: Mike McCready <66998419+MikeMcC399@users.noreply.github.com>
Date: Thu, 20 Feb 2025 12:47:45 +0100
Subject: [PATCH] test: add yarn modern caching

---
 .github/workflows/example-yarn-modern-pnp.yml |  6 ++++++
 .github/workflows/example-yarn-modern.yml     |  6 ++++++
 README.md                                     | 13 ++++++++++++-
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/example-yarn-modern-pnp.yml b/.github/workflows/example-yarn-modern-pnp.yml
index 69bd501a5..520ee55e8 100644
--- a/.github/workflows/example-yarn-modern-pnp.yml
+++ b/.github/workflows/example-yarn-modern-pnp.yml
@@ -14,6 +14,12 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
       - run: corepack enable yarn # experimental - see https://nodejs.org/docs/latest/api/corepack.html
+      - name: Set up Yarn cache
+        uses: actions/setup-node@v4
+        with:
+          node-version-file: '.node-version'
+          cache: yarn
+          cache-dependency-path: examples/yarn-modern-pnp/yarn.lock
       - name: Custom Yarn command
         uses: ./
         with:
diff --git a/.github/workflows/example-yarn-modern.yml b/.github/workflows/example-yarn-modern.yml
index b2cffe152..8efb38fc9 100644
--- a/.github/workflows/example-yarn-modern.yml
+++ b/.github/workflows/example-yarn-modern.yml
@@ -14,6 +14,12 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
       - run: corepack enable yarn # experimental - see https://nodejs.org/docs/latest/api/corepack.html
+      - name: Set up Yarn cache
+        uses: actions/setup-node@v4
+        with:
+          node-version-file: '.node-version'
+          cache: yarn
+          cache-dependency-path: examples/yarn-modern/yarn.lock
       - name: Custom Yarn command
         uses: ./
         with:
diff --git a/README.md b/README.md
index 0fd506756..0e241d0c5 100644
--- a/README.md
+++ b/README.md
@@ -1204,7 +1204,9 @@ jobs:
 
 ### Yarn Modern
 
-To install dependencies using a `yarn.lock` file from [Yarn Modern](https://yarnpkg.com/) (Yarn 2 and later) you need to override the default [Yarn 1 (Classic)](https://classic.yarnpkg.com/) installation command `yarn --frozen-lockfile`. You can do this by using the `install-command` parameter and specifying `yarn install` for example:
+To install dependencies using a `yarn.lock` file from [Yarn Modern](https://yarnpkg.com/) (Yarn 2 and later) you need to override the default [Yarn 1 (Classic)](https://classic.yarnpkg.com/) installation command `yarn --frozen-lockfile`. You can do this by using the `install-command` parameter and specifying `yarn install` as in the example below.
+
+The action supports built-in caching of Yarn Classic dependencies only. To cache Yarn Modern dependencies additionally use [actions/setup-node](https://github.com/actions/setup-node) and specify `cache: yarn`.
 
 ```yaml
 name: example-yarn-modern
@@ -1215,6 +1217,13 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v4
+      - run: corepack enable # (experimental and optional)
+      - name: Set up Yarn cache
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: yarn
+          cache-dependency-path: examples/yarn-modern/yarn.lock
       - name: Cypress run
         uses: cypress-io/github-action@v6
         with:
@@ -1231,6 +1240,8 @@ This example covers the [`.yarnrc.yml`](https://yarnpkg.com/configuration/yarnrc
 
 When using [Yarn Modern](https://yarnpkg.com/) (Yarn 2 and later) with [Plug'n'Play](https://yarnpkg.com/features/pnp) enabled, you will need to use the `command` parameter to run [`yarn`](https://yarnpkg.com/cli/run) instead of [`npx`](https://docs.npmjs.com/cli/v9/commands/npx).
 
+See the above [Yarn Modern](#yarn-modern) section for information on caching Yarn Modern dependencies.
+
 ```yaml
 name: example-yarn-modern-pnp
 on: push