add tests

hugr-core/src/extension/resolution.rs

@@ -163,3 +163,6 @@ impl ExtensionCollectionError {
         }
     }
 }
+
+#[cfg(test)]
+mod test;

hugr-core/src/extension/resolution/test.rs

@@ -0,0 +1,49 @@
+//! Tests for extension resolution.
+
+use rstest::rstest;
+
+use crate::extension::resolution::{update_op_extensions, update_op_types_extensions};
+use crate::extension::ExtensionRegistry;
+use crate::ops::{Input, OpType};
+use crate::std_extensions::arithmetic::int_ops;
+use crate::std_extensions::arithmetic::int_types;
+use crate::type_row;
+
+#[rstest]
+#[case::empty(Input { types: type_row![]}, ExtensionRegistry::default())]
+// A type with extra extensions in its instantiated type arguments.
+#[case::parametric_op(int_ops::IntOpDef::ieq.with_log_width(4),
+    ExtensionRegistry::new([int_ops::EXTENSION.to_owned(), int_types::EXTENSION.to_owned()]
+))]
+fn collect_type_extensions(#[case] op: impl Into<OpType>, #[case] extensions: ExtensionRegistry) {
+    let op = op.into();
+    let resolved = op.used_extensions().unwrap();
+    assert_eq!(resolved, extensions);
+}
+
+#[rstest]
+#[case::empty(Input { types: type_row![]}, ExtensionRegistry::default())]
+// A type with extra extensions in its instantiated type arguments.
+#[case::parametric_op(int_ops::IntOpDef::ieq.with_log_width(4),
+    ExtensionRegistry::new([int_ops::EXTENSION.to_owned(), int_types::EXTENSION.to_owned()]
+))]
+fn resolve_type_extensions(#[case] op: impl Into<OpType>, #[case] extensions: ExtensionRegistry) {
+    let op = op.into();
+
+    // Ensure that all the `Weak` pointers get invalidated by round-tripping via serialization.
+    let ser = serde_json::to_string(&op).unwrap();
+    let mut deser_op: OpType = serde_json::from_str(&ser).unwrap();
+
+    let dummy_node = portgraph::NodeIndex::new(0).into();
+
+    let mut used_exts = ExtensionRegistry::default();
+    update_op_extensions(dummy_node, &mut deser_op, &extensions).unwrap();
+    update_op_types_extensions(dummy_node, &mut deser_op, &extensions, &mut used_exts).unwrap();
+
+    let deser_extensions = deser_op.used_extensions().unwrap();
+
+    assert_eq!(
+        deser_extensions, extensions,
+        "{deser_extensions} != {extensions}"
+    );
+}