Refactor handlers to be in their own classes for easier maintainability

tests/test_json_handler.py

@@ -0,0 +1,56 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+import json
+import pytest
+import yaml
+
+from jinjaturtle.core import (
+    parse_config,
+    flatten_config,
+    generate_defaults_yaml,
+)
+from jinjaturtle.handlers.json import JsonHandler
+
+SAMPLES_DIR = Path(__file__).parent / "samples"
+
+
+def test_json_roundtrip():
+    json_path = SAMPLES_DIR / "foo.json"
+    assert json_path.is_file(), f"Missing sample JSON file: {json_path}"
+
+    fmt, parsed = parse_config(json_path)
+    assert fmt == "json"
+
+    flat_items = flatten_config(fmt, parsed)
+    defaults_yaml = generate_defaults_yaml("foobar", flat_items)
+    defaults = yaml.safe_load(defaults_yaml)
+
+    # Defaults: nested keys and list indices
+    assert defaults["foobar_foo"] == "bar"
+    assert defaults["foobar_nested_a"] == 1
+    # Bool normalized to string "true"
+    assert defaults["foobar_nested_b"] == "true"
+    assert defaults["foobar_list_0"] == 10
+    assert defaults["foobar_list_1"] == 20
+
+    # Template generation is done via JsonHandler.generate_template; we just
+    # make sure it produces a structure with the expected placeholders.
+    handler = JsonHandler()
+    templated = json.loads(handler.generate_template(parsed, role_prefix="foobar"))
+
+    assert templated["foo"] == "{{ foobar_foo }}"
+    assert "foobar_nested_a" in str(templated)
+    assert "foobar_nested_b" in str(templated)
+    assert "foobar_list_0" in str(templated)
+    assert "foobar_list_1" in str(templated)
+
+
+def test_generate_template_json_type_error():
+    """
+    Wrong type for JSON in JsonHandler.generate_template should raise TypeError.
+    """
+    handler = JsonHandler()
+    with pytest.raises(TypeError):
+        handler.generate_template(parsed="not a dict", role_prefix="role")