Extensible canonical internal processing refactoring

tests/test_extension_registry.py

@@ -0,0 +1,112 @@
+import pytest
+
+from markitect_tool.extension import (
+    ExtensionDescriptor,
+    ExtensionRegistry,
+    ExtensionRegistryError,
+    OptionalDependency,
+    ProcessingCapability,
+)
+
+
+def test_extension_descriptor_serializes_contract_metadata():
+    descriptor = ExtensionDescriptor(
+        id="query.selector",
+        kind="query-engine",
+        summary="Small selector query engine.",
+        capabilities=[ProcessingCapability(id="ast", kind="read")],
+        input_contract="Document + selector",
+        output_contract="QueryMatch[]",
+        diagnostics_namespace="query",
+        provenance_prefix="query.selector",
+        cli={"command": "mkt query"},
+        docs=["docs/query-extraction.md"],
+    )
+
+    data = descriptor.to_dict()
+
+    assert data["id"] == "query.selector"
+    assert data["kind"] == "query-engine"
+    assert data["capabilities"][0]["id"] == "ast"
+    assert data["cli"]["command"] == "mkt query"
+
+
+def test_extension_registry_lists_by_kind_and_capability():
+    selector = ExtensionDescriptor(
+        id="query.selector",
+        kind="query-engine",
+        capabilities=[ProcessingCapability(id="ast")],
+    )
+    local = ExtensionDescriptor(
+        id="backend.local-sqlite",
+        kind="backend",
+        capabilities=[ProcessingCapability(id="snapshots"), ProcessingCapability(id="fts")],
+    )
+    registry = ExtensionRegistry([local, selector])
+
+    assert [descriptor.id for descriptor in registry.list()] == [
+        "backend.local-sqlite",
+        "query.selector",
+    ]
+    assert [descriptor.id for descriptor in registry.list(kind="query-engine")] == [
+        "query.selector"
+    ]
+    assert [descriptor.id for descriptor in registry.require_capability("fts")] == [
+        "backend.local-sqlite"
+    ]
+
+
+def test_extension_registry_rejects_duplicate_ids():
+    descriptor = ExtensionDescriptor(id="query.selector", kind="query-engine")
+    registry = ExtensionRegistry([descriptor])
+
+    with pytest.raises(ExtensionRegistryError, match="Duplicate extension id"):
+        registry.register(descriptor)
+
+
+def test_extension_registry_checks_optional_dependencies():
+    registry = ExtensionRegistry(
+        [
+            ExtensionDescriptor(
+                id="query.jsonpath",
+                kind="query-engine",
+                optional_dependencies=[
+                    OptionalDependency(
+                        name="jsonpath_ng",
+                        package="jsonpath-ng",
+                        extra="query",
+                        required=True,
+                    ),
+                    OptionalDependency(name="tabulate"),
+                ],
+            )
+        ]
+    )
+
+    missing = registry.check_dependencies("query.jsonpath", available_modules=set())
+    available = registry.check_dependencies(
+        "query.jsonpath",
+        available_modules={"jsonpath_ng", "tabulate"},
+    )
+
+    assert not missing.compatible
+    assert missing.missing == ["jsonpath_ng"]
+    assert missing.optional_missing == ["tabulate"]
+    assert available.compatible
+
+
+def test_extension_descriptor_instantiates_factory():
+    descriptor = ExtensionDescriptor(
+        id="fake.extension",
+        kind="test",
+        factory=lambda: {"ready": True},
+    )
+
+    assert descriptor.instantiate() == {"ready": True}
+
+
+def test_extension_descriptor_requires_factory_to_instantiate():
+    descriptor = ExtensionDescriptor(id="fake.extension", kind="test")
+
+    with pytest.raises(ExtensionRegistryError, match="has no factory"):
+        descriptor.instantiate()