feat: initial release (#1)

Reviewed-on: #1
Co-authored-by: Timo Behrendt <t.behrendt@t00n.de>
Co-committed-by: Timo Behrendt <t.behrendt@t00n.de>

action.yml

@@ -0,0 +1,35 @@
+name: "Validate JSON by JSON Schema"
+description: "Validates JSON files using their $schema reference"
+author: "Timo Behrendt <t.behrendt@t00n.de>"
+
+inputs:
+  json-file:
+    description: "The JSON file to validate"
+    required: true
+
+runs:
+  using: "composite"
+  steps:
+    - uses: actions/setup-node@v5
+      with:
+        node-version-file: .nvmrc
+    - shell: bash
+      run: npm ci
+    - name: Extract schema
+      shell: bash
+      run: |
+        schema=$(jq -r '.["$schema"]' < ${{ inputs.json-file }})
+        if [ -n "$schema" ]; then
+          curl -s $schema > schema.json
+        else
+          echo "No schema found"
+          exit 0
+        fi
+    - name: Update the schema to the latest version
+      shell: bash
+      run: |
+        npx ajv-cli migrate -s schema.json -o schema.json
+    - name: Validate JSON
+      shell: bash
+      run: |
+        npx ajv-cli validate -s schema.json -d ${{ inputs.json-file }} --strict=false