Update README.md

README.md

@@ -10,7 +10,8 @@ By default, the repository that triggered the workflow is checked-out, for the r
 
 Refer [here](https://help.github.com/en/articles/events-that-trigger-workflows) to learn which commit `$GITHUB_SHA` points to for different events.
 
-Changes in V2:
+# What's new
+
 - Improved fetch performance
   - The default behavior now fetches only the SHA being checked-out
 - Script authenticated git commands
@@ -38,8 +39,9 @@ Refer [here](https://github.com/actions/checkout/blob/v1/README.md) for previous
     # Default: ${{ github.repository }}
     repository: ''
 
-    # Ref to checkout (SHA, branch, tag). For the repository that triggered the
-    # workflow, defaults to the ref/SHA for the event. Otherwise defaults to master.
+    # The branch, tag or SHA to checkout.  When checking out the repository that
+    # triggered a workflow, this defaults to the reference or SHA for that event.
+    # Otherwise, defaults to `master`.
     ref: ''
 
     # Access token for clone repository
@@ -66,7 +68,7 @@ Refer [here](https://github.com/actions/checkout/blob/v1/README.md) for previous
 ## Checkout a different branch
 
 ```yaml
-- uses: actions/checkout@preview
+- uses: actions/checkout@v2-beta
   with:
     ref: some-branch
 ```
@@ -74,7 +76,7 @@ Refer [here](https://github.com/actions/checkout/blob/v1/README.md) for previous
 ## Checkout a different, private repository
 
 ```yaml
-- uses: actions/checkout@preview
+- uses: actions/checkout@v2-beta
   with:
     repository: myAccount/myRepository
     ref: refs/heads/master
@@ -82,6 +84,14 @@ Refer [here](https://github.com/actions/checkout/blob/v1/README.md) for previous
 ```
 > - `${{ github.token }}` is scoped to the current repository, so if you want to checkout another repository that is private you will need to provide your own [PAT](https://help.github.com/en/github/authenticating-to-github/creating-a-personal-access-token-for-the-command-line).
 
+## Checkout the HEAD commit of a PR, rather than the merge commit
+
+```yaml
+- uses: actions/checkout@v2-beta
+  with:
+    ref: ${{ github.event.after }}
+```
+
 # License
 
 The scripts and documentation in this project are released under the [MIT License](LICENSE)

action.yml

@@ -1,13 +1,14 @@
 name: 'Checkout'
-description: 'Checkout a Git repository'
+description: 'Checkout a Git repository at a particular version'
 inputs: 
   repository:
     description: 'Repository name with owner. For example, actions/checkout'
     default: ${{ github.repository }}
   ref:
     description: >
-      Ref to checkout (SHA, branch, tag). For the repository that triggered the
-      workflow, defaults to the ref/SHA for the event. Otherwise defaults to master.
+      The branch, tag or SHA to checkout.  When checking out the repository
+      that triggered a workflow, this defaults to the reference or SHA for
+      that event.  Otherwise, defaults to `master`.
   token:
     description: 'Access token for clone repository'
     default: ${{ github.token }}