feat: support .tool-versions

Author: xhyrom

.github/workflows/test.yml

@@ -76,3 +76,34 @@ jobs:
             echo "Expected version to be 1.0.0, got ${{ steps.bun.outputs.version }}"
             exit 1
           fi
+  setup-bun-from-tool-versions:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os:
+          - ubuntu-latest
+          - macos-latest
+        content:
+          - "bun 1.0.0"
+          - "bun1.0.0"
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Setup package.json
+        run: |
+          echo "bun ${{ matrix.content }}" > .tool-versions
+      - name: Setup Bun
+        uses: ./
+      - name: Run Bun
+        id: bun
+        run: |
+          bun --version
+          echo "version=$(bun --version)" >> $GITHUB_OUTPUT
+      - name: Check version
+        run: |
+          if [[ "${{ steps.bun.outputs.version }}" == "1.0.0" ]]; then
+            echo "Version is 1.0.0"
+          else
+            echo "Expected version to be 1.0.0, got ${{ steps.bun.outputs.version }}"
+            exit 1
+          fi

src/index.ts

@@ -36,8 +36,32 @@ function readVersionFromPackageJson(): string | undefined {
   }
 }
 
+function readVersionFromToolVersions(): string | undefined {
+  const cwd = process.env.GITHUB_WORKSPACE;
+  if (!cwd) {
+    return;
+  }
+  const path = join(cwd, ".tool-versions");
+  try {
+    if (!existsSync(path)) {
+      return;
+    }
+
+    const match = readFileSync(path, "utf8").match(/^bun\s(?<version>.*?)$/m);
+
+    return match?.groups?.version;
+  } catch (error) {
+    const { message } = error as Error;
+    warning(`Failed to read .tool-versions: ${message}`);
+  }
+}
+
 runAction({
-  version: getInput("bun-version") || readVersionFromPackageJson() || undefined,
+  version:
+    getInput("bun-version") ||
+    readVersionFromPackageJson() ||
+    readVersionFromToolVersions() ||
+    undefined,
   customUrl: getInput("bun-download-url") || undefined,
   registryUrl: getInput("registry-url") || undefined,
   scope: getInput("scope") || undefined,