fix(vscode): symbols that cannot be renamed seem to silently fail (#6573

)

## Checklist
fixes: #6564
 listening to the `textDocument/prepareRename` request and allowing rename only for symbols
https://www.loom.com/share/7e5d68e50029474f8c23b65ba2cf20aa?sid=5160bb05-b969-4e88-8b60-74422556c673

- [ ] Title matches [Winglang's style guide](https://www.winglang.io/contributing/start-here/pull_requests#how-are-pull-request-titles-formatted)
- [ ] Description explains motivation and solution
- [ ] Tests added (always)
- [ ] Docs updated (only required for features)
- [ ] Added `pr/e2e-full` label if this feature requires end-to-end testing

*By submitting this pull request, I confirm that my contribution is made under the terms of the [Wing Cloud Contribution License](https://github.com/winglang/wing/blob/main/CONTRIBUTION_LICENSE.md)*.

apps/wing/src/commands/lsp.ts

@@ -100,7 +100,7 @@ export async function lsp() {
         hoverProvider: true,
         documentSymbolProvider: true,
         definitionProvider: true,
-        renameProvider: true,
+        renameProvider: { prepareProvider: true },
       },
     };
     return result;
@@ -219,6 +219,9 @@ export async function lsp() {
   connection.onRenameRequest(async (params) => {
     return callWing("wingc_on_rename", params);
   });
+  connection.onPrepareRename(async (params) => {
+    return callWing("wingc_on_prepare_rename", params);
+  });
   connection.onHover(async (params) => {
     return callWing("wingc_on_hover", params);
   });

libs/wingc/src/lsp/mod.rs

@@ -3,6 +3,7 @@ mod completions;
 mod document_symbols;
 mod goto_definition;
 mod hover;
+mod rename_prepare;
 mod rename_request;
 mod rename_visitor;
 mod signature;

libs/wingc/src/lsp/rename_prepare.rs

@@ -0,0 +1,345 @@
+use crate::lsp::sync::PROJECT_DATA;
+use crate::visit::Visit;
+use crate::wasm_util::extern_json_fn;
+use lsp_types::{PrepareRenameResponse, TextDocumentPositionParams};
+
+use super::rename_visitor::RenameVisitor;
+use super::sync::{check_utf8, WING_TYPES};
+
+#[no_mangle]
+pub unsafe extern "C" fn wingc_on_prepare_rename(ptr: u32, len: u32) -> u64 {
+	extern_json_fn(ptr, len, on_prepare_rename)
+}
+
+pub fn on_prepare_rename(params: TextDocumentPositionParams) -> PrepareRenameResponse {
+	WING_TYPES.with(|types| {
+		let types = types.borrow();
+		PROJECT_DATA.with(|project_data| -> PrepareRenameResponse {
+			let project_data = project_data.borrow();
+			let uri = params.text_document.uri;
+			let file = check_utf8(uri.to_file_path().expect("LSP only works on real filesystems"));
+			let scope = project_data.asts.get(&file).unwrap();
+
+			let position = params.position;
+
+			let mut reference_visitor = RenameVisitor::new(&types);
+			reference_visitor.visit_scope(scope);
+
+			reference_visitor.prepare_rename(position)
+		})
+	})
+}
+
+#[cfg(test)]
+mod tests {
+	use crate::lsp::rename_prepare::*;
+	use crate::lsp::sync::test_utils::*;
+
+	/// Creates a snapshot test for a given wing program's rename_prepare at a given position
+	/// In the wing program, place a comment "//^" into the text where the "^" is pointing to the desired character position
+	/// To assert on the target range of the result, place a comment "//-" below the target, with additional "-" characters to extend the range
+	///
+	/// First parameter will be the name of the tests, as well as the identifier to use for the list of completion in the asserts (see last parameter)
+	/// Second parameter is the wing code block as a string literal
+	/// After the first two parameters, additional statements can optionally be provided to assert on the returned data.
+	///
+	/// Result is a PrepareRenameResponse
+	macro_rules! test_rename_prepare {
+		($name:ident, $code:literal) => {
+			test_rename_prepare!($name, $code,);
+		};
+		($name:ident, $code:literal, $($assertion:stmt)*) => {
+			#[test]
+			fn $name() {
+				// NOTE: this is needed for debugging to work regardless of where you run the test
+				std::env::set_current_dir(env!("CARGO_MANIFEST_DIR")).unwrap();
+
+				let text_document_position_params = load_file_with_contents($code);
+
+				let $name = on_prepare_rename(TextDocumentPositionParams {
+					text_document: text_document_position_params.text_document.clone(),
+          position: text_document_position_params.position.clone(),
+				});
+
+      let ranges = get_ranges($code);
+
+      match $name {
+        PrepareRenameResponse::DefaultBehavior{default_behavior} => {
+          assert_eq!(
+            ranges.len(),
+						0,
+						"target_range did not match"
+					);
+          assert_eq!(
+            default_behavior,
+						false,
+						"target_range did not match"
+					);
+        }
+          PrepareRenameResponse::Range(range) => {
+            assert_eq!(
+              ranges[0],
+              range,
+              "target_range did not match"
+            );
+      }
+      PrepareRenameResponse::RangeWithPlaceholder{range, ..} => {
+        assert_eq!(
+          ranges[0],
+          range,
+          "target_range did not match"
+        );
+  }
+    }
+
+				$($assertion)*
+			}
+		};
+	}
+
+	test_rename_prepare!(
+		cant_rename_equal_sign,
+		r#"
+let thing = "thing";
+let thing2 = thing;
+         //^
+		"#
+	);
+
+	test_rename_prepare!(
+		cant_rename_let,
+		r#"
+let thing = "thing";
+//^
+let thing2 = thing;
+		"#
+	);
+
+	test_rename_prepare!(
+		cant_rename_str,
+		r#"
+let thing = "thing";
+              //^
+let thing2 = thing;
+		"#
+	);
+
+	test_rename_prepare!(
+		cant_rename_semicolon,
+		r#"
+let thing = "thing";
+                 //^
+let thing2 = thing;
+		"#
+	);
+	//
+
+	test_rename_prepare!(
+		cant_rename_numbers,
+		r#"
+let var thing = 6;
+              //^   
+		"#
+	);
+
+	test_rename_prepare!(
+		cant_rename_log,
+		r#"
+    log("hi!")
+   //^
+  
+		"#
+	);
+
+	test_rename_prepare!(
+		can_rename_symbol,
+		r#"
+    let var thing = 6;
+    if (thing > 8) {
+    thing = 6;
+
+    } else {
+    if (thing < 0) {
+      let thing = 0;
+      log(thing);
+        //----^
+    }
+    log(thing)
+    }
+		"#
+	);
+
+	test_rename_prepare!(
+		cant_rename_class_keyword,
+		r#"
+class User {
+//^
+  name: str;
+}
+		"#
+	);
+
+	test_rename_prepare!(
+		cant_rename_for,
+		r#"
+    bring cloud;
+
+    let buckets = [new cloud.Bucket()];
+    for bucket in buckets {
+  //^
+      bucket.addObject("bucket","bucket");
+      log(bucket.toString());
+    }
+		"#
+	);
+
+	test_rename_prepare!(
+		cant_rename_in,
+		r#"
+    bring cloud;
+
+    let buckets = [new cloud.Bucket()];
+    for bucket in buckets {
+              //^
+      bucket.addObject("bucket","bucket");
+      log(bucket.toString());
+    }
+		"#
+	);
+
+	test_rename_prepare!(
+		can_rename_vars,
+		r#"
+    bring cloud;
+
+    let buckets = [new cloud.Bucket()];
+      //------^
+		"#
+	);
+
+	// TODO: not supported yet - therefore disabled
+	test_rename_prepare!(
+		cant_rename_namespace,
+		r#"
+    bring cloud;
+           //^
+    let bucket = new cloud.Bucket();
+		"#
+	);
+
+	// TODO: not supported yet - therefore disabled
+	test_rename_prepare!(
+		cant_rename_namespace_from_property,
+		r#"
+    bring cloud;
+    let bucket = new cloud.Bucket();
+                     //^
+		"#
+	);
+
+	test_rename_prepare!(
+		cant_rename_comments,
+		r#"
+    bring cloud;
+    // let bucket = new cloud.Bucket();
+          //^
+		"#
+	);
+
+	test_rename_prepare!(
+		cant_rename_tests,
+		r#"
+    test "this is a test" {
+    //^ 
+      assert(true);
+    } 
+		"#
+	);
+
+	// TODO: not supported yet- therefore disabled
+	test_rename_prepare!(
+		cant_rename_struct_key,
+		r#"
+    struct user {
+      name: str;
+      //^
+    }
+ 
+ let a: user = {name: "a"};
+		"#
+	);
+
+	test_rename_prepare!(
+		cant_rename_struct_keyword,
+		r#"
+    struct user {
+    //^
+      name: str;
+    }
+    
+    let a: user = {name: "a"};
+		"#
+	);
+	// TODO: not supported yet - therefore disabled
+	test_rename_prepare!(
+		cant_rename_interface_key,
+		r#"
+    interface ICat {
+      inflight stepOnKeyboard(): str;
+              //^
+    }
+    
+    class Cat impl ICat {
+      pub inflight stepOnKeyboard(): str {
+                 
+         return "/..,.o0e";
+      }
+    }
+    
+    let hershy = new Cat();
+    
+    test "cat misbehaves" {
+      hershy.stepOnKeyboard();
+    }
+		"#
+	);
+
+	test_rename_prepare!(
+		cant_rename_interface_keyword,
+		r#"
+    interface ICat {
+      //^
+      inflight stepOnKeyboard(): str;
+    }
+    
+    class Cat impl ICat {
+      pub inflight stepOnKeyboard(): str {
+                 
+         return "/..,.o0e";
+      }
+    }
+    
+    let hershy = new Cat();
+    
+    test "cat misbehaves" {
+      hershy.stepOnKeyboard();
+    }
+		"#
+	);
+
+	test_rename_prepare!(
+		cant_rename_types,
+		r#"
+    let a: str = "hi";
+          //^
+    "#
+	);
+
+	test_rename_prepare!(
+		cant_rename_json_val,
+		r#"
+    let j = {a: "hi"};
+               //^
+    "#
+	);
+}