feat: pre-req check

README.md

@@ -39,6 +39,8 @@ jobs:
 
 ## Prerequisites
 
+### Team and Authentication
+
 1. Create a GitHub team and add at least one member
 2. Authentication options:
   - GitHub App
@@ -62,6 +64,13 @@ Notes:
 - A Personal Access Token (PAT) is not used since we want the comment to show as from a bot
 - The `github.token` is not used since the token can't provide hyperlinks for @ mentions since it doesn't have the scope for org teams, only repository data
 
+### Runner Software Requirements
+
+Required software installed on runner:
+
+  - [`gh` (GitHub CLI)](https://cli.github.com/)
+  - [`jq`](https://jqlang.github.io/jq/download/)
+
 ## Breaking Changes
 
 ### v1 to v2

action.yml

@@ -45,6 +45,15 @@ runs:
       shell: bash
       run: |
         # "checking for a ${{ inputs.approve-command }} command in the comments from someone in the ${{ inputs.team-name}} team"
+
+        # prerequisite check
+        for cmd in gh jq; do
+          if ! command -v $cmd &> /dev/null; then
+            echo "::error title=${cmd} not installed::Could not find \`${cmd}\` on the runner"
+            exit 1
+          fi
+        done
+
         # getting team membership"
         echo "getting team membership for the team: @${{ github.repository_owner }}/${{ inputs.team-name }} ..."
         users=$(gh api --paginate '${{ github.event.organization.url }}/teams/${{ inputs.team-name }}/members' --jq '.[].login')