Improve run-komac action: safer shell, optional args, and outputs

action.yml

@@ -1,69 +1,100 @@
-name: 'Run Komac'
-description: 'Sets up and runs Komac with optional customizations'
-branding:
-  color: 'blue'
-  icon: 'upload-cloud'
-
-inputs:
-  komac-version:
-    description: 'Komac version to use (default: latest)'
-    required: false
-    default: 'latest'
-  args:
-    description: 'Arguments to run Komac with'
-    required: true
-  custom-fork-owner:
-    description: 'Specify a custom fork owner of Komac, if any'
-    required: false
-  custom-tool:
-    description: 'Name of a custom tool to use with Komac'
-    required: false
-  custom-tool-url:
-    description: 'URL of the custom tool, if applicable'
-    required: false
-
-runs:
-  using: 'composite'
-  steps:
-    - name: Check for Komac Installation
-      id: check_komac
-      shell: bash
-      run: |
-        if komac --version &> /dev/null; then
-          echo "Komac is already installed."
-          echo "komac_installed=true" >> $GITHUB_OUTPUT
-        else
-          echo "Komac is not installed."
-          echo "komac_installed=false" >> $GITHUB_OUTPUT
-        fi
-
-    - name: Install binstall
-      if: steps.check_komac.outputs.komac_installed == 'false'
-      uses: cargo-bins/cargo-binstall@main
-
-    - name: Install Komac
-      if: steps.check_komac.outputs.komac_installed == 'false'
-      shell: bash
-      run: |
-        if [ "${{ inputs.komac-version }}" == 'latest' ]; then
-          cargo binstall komac -y
-        else
-          cargo binstall komac@${{ inputs.komac-version }} -y
-        fi
-
-    - name: Set Custom Environment Variables
-      shell: bash
-      run: |
-        if [[ -n "${{ inputs.custom-fork-owner }}" ]]; then
-          echo "KOMAC_FORK_OWNER=${{ inputs.custom-fork-owner }}" >> $GITHUB_ENV
-        fi
-        if [[ -n "${{ inputs.custom-tool }}" ]]; then
-          echo "KOMAC_CREATED_WITH=${{ inputs.custom-tool }}" >> $GITHUB_ENV
-        fi
-        if [[ -n "${{ inputs.custom-tool-url }}" ]]; then
-          echo "KOMAC_CREATED_WITH_URL=${{ inputs.custom-tool-url }}" >> $GITHUB_ENV
-        fi
-
-    - name: Run Komac
-      shell: bash
-      run: komac ${{ inputs.args }}
+name: 'Run Komac'
+description: 'Sets up and runs Komac with optional customizations'
+branding:
+  color: 'blue'
+  icon: 'upload-cloud'
+
+inputs:
+  komac-version:
+    description: 'Komac version to use (default: latest)'
+    required: false
+    default: 'latest'
+  args:
+    description: 'Arguments to run Komac with'
+    required: false
+    default: ''
+  custom-fork-owner:
+    description: 'Specify a custom fork owner of Komac, if any'
+    required: false
+  custom-tool:
+    description: 'Name of a custom tool to use with Komac'
+    required: false
+  custom-tool-url:
+    description: 'URL of the custom tool, if applicable'
+    required: false
+
+outputs:
+  komac-exit-code:
+    description: 'Exit code returned by komac'
+
+runs:
+  using: 'composite'
+  steps:
+    - name: Check for Komac Installation
+      id: check_komac
+      shell: bash
+      run: |
+        # fail fast and safer shell behavior
+        set -euo pipefail
+
+        # Prefer using command -v to detect whether komac is available in PATH
+        if command -v komac >/dev/null 2>&1; then
+          echo "Komac is already installed."
+          echo "komac_installed=true" >> $GITHUB_OUTPUT
+        else
+          echo "Komac is not installed."
+          echo "komac_installed=false" >> $GITHUB_OUTPUT
+        fi
+
+    - name: Install binstall
+      if: steps.check_komac.outputs.komac_installed == 'false'
+      # Pin this to a released tag or commit instead of `main` for security.
+      # e.g., cargo-bins/cargo-binstall@vX.Y.Z or a commit SHA.
+      uses: cargo-bins/cargo-binstall@main
+
+    - name: Install Komac
+      if: steps.check_komac.outputs.komac_installed == 'false'
+      shell: bash
+      run: |
+        set -euo pipefail
+        if [ "${{ inputs.komac-version }}" = 'latest' ]; then
+          cargo binstall komac -y
+        else
+          cargo binstall "komac@${{ inputs.komac-version }}" -y
+        fi
+
+    - name: Set Custom Environment Variables
+      shell: bash
+      run: |
+        set -euo pipefail
+        if [[ -n "${{ inputs.custom-fork-owner }}" ]]; then
+          echo "KOMAC_FORK_OWNER=${{ inputs.custom-fork-owner }}" >> $GITHUB_ENV
+        fi
+        if [[ -n "${{ inputs.custom-tool }}" ]]; then
+          echo "KOMAC_CREATED_WITH=${{ inputs.custom-tool }}" >> $GITHUB_ENV
+        fi
+        if [[ -n "${{ inputs.custom-tool-url }}" ]]; then
+          echo "KOMAC_CREATED_WITH_URL=${{ inputs.custom-tool-url }}" >> $GITHUB_ENV
+        fi
+
+    - name: Run Komac
+      id: run_komac
+      shell: bash
+      run: |
+        set -euo pipefail
+
+        # If args were provided, pass them; otherwise run with no args
+        if [[ -n "${{ inputs.args }}" ]]; then
+          # inputs.args is inserted by GitHub Actions — it will be passed as-is.
+          komac ${{ inputs.args }}
+        else
+          komac
+        fi
+        EXIT_CODE=$?
+        echo "komac_exit_code=$EXIT_CODE" >> $GITHUB_OUTPUT
+
+    - name: Export komac exit code as action output
+      shell: bash
+      run: |
+        set -euo pipefail
+        echo "komac-exit-code=${{ steps.run_komac.outputs.komac_exit_code }}" >> $GITHUB_OUTPUT