Fix unmodeled methods always being marked as unsaved

When opening a library group in the model editor, unmodeled methods
would always be marked as unsaved, even if there were no changes. This
was because the `ModelKindDropdown` component did not properly take into
account that the `kind` for an unmodeled method should be an empty
string. It would always try setting it to `undefined`, which would cause
the method to be marked as unsaved. This fixes it by checking if there
are valid kinds before setting the kind to the first one.

extensions/ql-vscode/src/view/model-editor/ModelKindDropdown.tsx

@@ -63,7 +63,16 @@ export const ModelKindDropdown = ({
 
   useEffect(() => {
     const value = modeledMethod?.kind;
-    if (value === undefined && kinds.length > 0) {
+
+    if (kinds.length === 0) {
+      if (value !== "") {
+        onChangeKind("");
+      }
+
+      return;
+    }
+
+    if (value === undefined) {
       onChangeKind(kinds[0]);
     }
 

extensions/ql-vscode/src/view/model-editor/__tests__/ModelKindDropdown.spec.tsx

@@ -92,4 +92,45 @@ describe(ModelKindDropdown.name, () => {
       }),
     );
   });
+
+  it("does not call onChange when unmodeled and the kind is valid", () => {
+    const method = createMethod();
+    const modeledMethod = createModeledMethod({
+      type: "none",
+      kind: "",
+    });
+
+    render(
+      <ModelKindDropdown
+        method={method}
+        modeledMethod={modeledMethod}
+        onChange={onChange}
+      />,
+    );
+
+    expect(onChange).not.toHaveBeenCalled();
+  });
+
+  it("calls onChange when unmodeled and the kind is valid", () => {
+    const method = createMethod();
+    const modeledMethod = createModeledMethod({
+      type: "none",
+      kind: "local",
+    });
+
+    render(
+      <ModelKindDropdown
+        method={method}
+        modeledMethod={modeledMethod}
+        onChange={onChange}
+      />,
+    );
+
+    expect(onChange).toHaveBeenCalledTimes(1);
+    expect(onChange).toHaveBeenCalledWith(
+      expect.objectContaining({
+        kind: "",
+      }),
+    );
+  });
 });