Parse the event.json of an action (e.g. push)

lnx/parse-event/action.yml

@@ -0,0 +1,38 @@
+name: 'parse-event'
+description: 'Parses a JSON file, that contains all information about the last event.'
+
+outputs:
+  base-commit:
+    description: 'The hash of the base commit of the event. This is the commit that was previously at the head of the branch before the event.'
+    value: ${{ steps.parse.outputs.hash }}
+  fetch-depth:
+    description: 'The number of commits needed to get the whole diff of the event.'
+    value: ${{ steps.parse.outputs.count }}
+
+runs:
+  using: 'composite'
+  steps:
+    - name: Install jq
+      shell: bash
+      run: |
+        apt-get update &> /dev/null
+        apt-get install -y jq &> /dev/null
+        echo "$(which jq): $(jq --version)"
+
+    - name: Parse event
+      id: parse
+      shell: bash
+      run: |
+        hash=$(jq -r '.before' "${{ github.event_path }}")
+        count=$(jq -r '.commits | length + 1' "${{ github.event_path }}")
+        serverUrl="${{ github.server_url }}"
+        host=${serverUrl#*://}
+
+        echo "OUT: hash=$hash"
+        echo "hash=$hash" >> $GITHUB_OUTPUT
+
+        echo "OUT: count=$count"
+        echo "count=$count" >> $GITHUB_OUTPUT
+
+        echo "ENV: CI_SERVER_HOST=$host"
+        echo "CI_SERVER_HOST=$host" >> $GITHUB_ENV