Find latest version for GitHub release assets

.github/workflows/ci.yml

@@ -48,6 +48,21 @@ jobs:
         run: ls -l '${{ steps.setup-hlint.outputs.file }}'
       - run: hlint --version
 
+      # Same, with inferred version
+      - id: setup-hlint-latest
+        uses: ./
+        with:
+          name: "hlint"
+          url: "https://github.com/ndmitchell/{name}/releases/download/v{version}/{name}-{version}-{arch}-{os}.{ext}"
+          subdir: "{name}-{version}"
+          os-darwin: osx
+          os-win32: windows
+          arch: x86_64
+      - run: ls -l '${{ steps.setup-hlint-latest.outputs.directory }}'
+      - if: ${{ matrix.runner != 'windows-latest' }} # it's .exe on win32
+        run: ls -l '${{ steps.setup-hlint-latest.outputs.file }}'
+      - run: hlint --version
+
       - id: setup-dms
         uses: ./
         with:
@@ -89,6 +104,16 @@ jobs:
       - if: ${{ matrix.runner == 'ubuntu-latest' }}
         run: bluebook --help
 
+      # Test inferring "latest"
+      - if: ${{ matrix.runner == 'ubuntu-latest' }}
+        uses: ./
+        with:
+          name: bluebook
+          url: "https://github.com/pbrisbin/{name}/releases/download/v{version}/{name}-{os}-{arch}"
+          no-extract: "true"
+      - if: ${{ matrix.runner == 'ubuntu-latest' }}
+        run: bluebook --help
+
       #
       # Random example from Freckle, that's a private repo. TODO: skip in
       # forks.

action-types.yml

@@ -159,6 +159,9 @@ inputs:
   github-token:
     type: string
 
+  github-token-for-latest:
+    type: string
+
 outputs:
   directory:
     type: string

action.yml

@@ -6,8 +6,12 @@ inputs:
     required: true
 
   version:
-    description: "Version of the tool"
-    required: true
+    description: |
+      Version of the tool
+
+      Required unless `url` is to a GitHub release asset, in which case the
+      latest release will be looked up if left blank.
+    required: false
 
   url:
     description: |
@@ -110,6 +114,13 @@ inputs:
 
       https://docs.github.com/en/rest/releases/assets?apiVersion=2022-11-28#get-a-release-asset
 
+  github-token-for-latest:
+    description: |
+      Token used for looking up a latest release when `version` is blank, `url`
+      is to a GitHub release asset, and `github-token` is not set. This is to
+      avoid rate limits when interacting with public releases.
+    default: ${{ github.token }}
+
 outputs:
   directory:
     description: Directory that was added to `$PATH` as result of setup.