Extensible canonical internal processing refactoring

tests/test_query_engine_registry.py

@@ -0,0 +1,28 @@
+from markitect_tool.core import parse_markdown
+from markitect_tool.query import (
+    default_query_engine_registry,
+    extract_document_with_engine,
+    query_document_with_engine,
+)
+
+
+def test_default_query_engine_registry_exposes_builtin_descriptors():
+    registry = default_query_engine_registry()
+
+    descriptors = registry.extension_registry().to_dict()["extensions"]
+
+    assert [engine.descriptor.id for engine in registry.list()] == ["jsonpath", "selector"]
+    assert {descriptor["id"] for descriptor in descriptors} == {"selector", "jsonpath"}
+    assert registry.get("selector").descriptor.cli["commands"][0] == "mkt query"
+    assert registry.get("jsonpath").descriptor.optional_dependencies[0].name == "jsonpath_ng"
+
+
+def test_query_document_with_engine_uses_selector_registry():
+    document = parse_markdown("# Doc\n\n## Decision\n\nChosen.\n")
+
+    matches = query_document_with_engine(document, "sections[heading=Decision]", engine="selector")
+    extracted = extract_document_with_engine(document, "sections[heading=Decision]", engine="selector")
+
+    assert matches[0].kind == "section"
+    assert matches[0].path == "$.sections[1]"
+    assert extracted == ["## Decision\n\nChosen."]