fix: Updates to jsonschema dereference script (#235)

- Fix linting errors when opening files without selecting an encoding
 - Search for values.schema.tmpl.json instead of Chart.lock files
 - Rename 'schema' variables to prevent shadowing or redefining
 - Add Module docstring
 - Add comments explaining what is being done
 - Rename file to follow Python module naming convention of snake_case
 - Rename some variables to correctly represent what they are doing, schema_template instead of chart, etc.
 - Update pre-commit to point to new jsonschema_dereference script name

Signed-off-by: Corey Daley <cdaley@redhat.com>

Author: Corey Daley

.pre-commit-config.yaml

@@ -14,7 +14,7 @@ repos:
     hooks:
       - id: jsonschema-dereference
         name: jsonschema-dereference
-        entry: python .pre-commit/jsonschema-dereference.py
+        entry: python .pre-commit/jsonschema_dereference.py
         additional_dependencies: [jsonref]
         language: python
         types_or: [yaml, json]

.pre-commit/jsonschema-dereference.py

@@ -0,0 +1,54 @@
+""" 
+This Python module:
+  - Searches for JSON Schema templates with the name values.schema.tmpl.json
+  - Dereferences any $refs contained in those files
+  - Outputs the new Schema to a values.schema.json file in the same directory
+"""
+
+import sys
+import json
+from typing import List, Dict, Any
+from pathlib import Path
+
+# External library dependency
+# Install with 'pip install jsonref'
+import jsonref
+
+# File to write the dereferenced JSON Schema to
+JSONSCHEMA_NAME = "values.schema.json"
+# File that contains the JSON Schema that needs dereferencing
+JSONSCHEMA_TEMPLATE_NAME = "values.schema.tmpl.json"
+
+def load_template_schema(schema_dir: Path) -> Dict[str, Any]:
+    """Load the schema template values.schema.tmpl.json"""
+    with open(schema_dir / JSONSCHEMA_TEMPLATE_NAME, "r", encoding="utf-8") as f:
+        return json.loads(f.read())
+
+def save(schema_dir: Path, schema_data: Any):
+    """Save the dereferenced schema to values.schema.json"""
+    with open(schema_dir / JSONSCHEMA_NAME, "w", encoding="utf-8") as f:
+        json.dump(schema_data, f, indent=4, sort_keys=True)
+
+if __name__ == '__main__':
+    # Search for all values.schema.tmpl.json files
+    schema_templates = [p.parent for p in Path(".").rglob(JSONSCHEMA_TEMPLATE_NAME)]
+
+    # Create a list to hold any exceptions
+    errors: List[BaseException] = []
+    # Iterate over the List of found schema templates
+    for schema_template in schema_templates:
+        try:
+            # Load the schema into a variable as JSON
+            st = load_template_schema(schema_template)
+            # Dereference all of the $refs
+            s = jsonref.replace_refs(st)
+            # Save the dereferenced JSON
+            save(schema_template, s)
+        except BaseException as e:
+            # Print any errors to the screen
+            print(f"Could not process schema for '{schema_template}': {e}")
+            # Append any exceptions to the errors List
+            errors.append(e)
+    if errors:
+        # Exit with status 1 if any exceptions were thrown
+        sys.exit(1)