python: expose LinkMLValue.equals(); tests: add python_equals coverage

Author: Frank Dekervel

src/python/src/lib.rs

@@ -478,6 +478,11 @@ impl Clone for PyLinkMLValue {
 
 #[pymethods]
 impl PyLinkMLValue {
+    /// Semantic equality per LinkML Instances spec.
+    /// Compares this value with another `LinkMLValue`.
+    fn equals(&self, other: &PyLinkMLValue) -> bool {
+        self.value.equals(&other.value)
+    }
     #[getter]
     fn slot_name(&self) -> Option<String> {
         match &self.value {

src/python/tests/python_equals.rs

@@ -0,0 +1,75 @@
+use linkml_runtime_python::runtime_module;
+use pyo3::prelude::*;
+use pyo3::types::PyDict;
+use std::path::PathBuf;
+
+fn data_path(name: &str) -> PathBuf {
+    let base = PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+    let candidates = [
+        base.join("../runtime/tests/data").join(name),
+        base.join("../schemaview/tests/data").join(name),
+        base.join("tests/data").join(name),
+    ];
+    for c in candidates {
+        if c.exists() {
+            return c;
+        }
+    }
+    panic!("test data not found: {}", name);
+}
+
+#[test]
+fn python_equals_api() {
+    pyo3::prepare_freethreaded_python();
+    Python::with_gil(|py| {
+        let module = PyModule::new(py, "linkml_runtime").unwrap();
+        runtime_module(&module).unwrap();
+        let sys = py.import("sys").unwrap();
+        let modules = sys.getattr("modules").unwrap();
+        let sys_modules = modules.downcast::<PyDict>().unwrap();
+        sys_modules.set_item("linkml_runtime", module).unwrap();
+
+        let locals = PyDict::new(py);
+        locals
+            .set_item(
+                "schema_path",
+                data_path("personinfo.yaml").to_str().unwrap(),
+            )
+            .unwrap();
+
+        pyo3::py_run!(
+            py,
+            *locals,
+            r#"
+import linkml_runtime as lr
+import json
+sv = lr.make_schema_view(schema_path)
+cls = sv.get_class_view('Container')
+
+doc1 = {
+  'objects': [
+    {
+      'objecttype': 'personinfo:Person',
+      'id': 'P:1',
+      'name': 'Alice',
+      'current_address': None
+    }
+  ]
+}
+doc2 = {
+  'objects': [
+    {
+      'objecttype': 'personinfo:Person',
+      'id': 'P:1',
+      'name': 'Alice'
+    }
+  ]
+}
+
+v1 = lr.load_json(json.dumps(doc1), sv, cls)
+v2 = lr.load_json(json.dumps(doc2), sv, cls)
+assert v1['objects'][0].equals(v2['objects'][0])
+"#
+        );
+    });
+}