LSP: Fix file URI handling + warn about workspace project mismatch

Author: HolonProduction

modules/gdscript/language_server/gdscript_language_protocol.cpp

@@ -173,6 +173,35 @@ void GDScriptLanguageProtocol::_bind_methods() {
 Dictionary GDScriptLanguageProtocol::initialize(const Dictionary &p_params) {
 	lsp::InitializeResult ret;
 
+	{
+		// Warn if the workspace root does not match with the project that is currently open in Godot,
+		// since it might lead to unexpected behaviour, like wrong warnings about duplicate class names.
+
+		String root = "";
+		Variant root_uri_var = p_params["rootUri"];
+		Variant root_var = p_params["rootUri"];
+		if (root_uri_var.is_string()) {
+			root = get_workspace()->get_file_path(root_uri_var);
+		} else if (root_var.is_string()) {
+			root = root_var;
+		}
+
+		if (ProjectSettings::get_singleton()->localize_path(root) != "res://") {
+			lsp::ShowMessageParams params{
+				lsp::MessageType::Warning,
+				"The GDScript Language Server might not work correctly with other projects than the one opened in Godot."
+			};
+			Variant res = make_notification("window/showMessage", params.to_json());
+
+			Ref<LSPeer> peer = clients.get(latest_client_id);
+			if (peer.is_valid()) {
+				String msg = res.to_json_string();
+				msg = format_output(msg);
+				(*peer)->res_queue.push_back(msg.utf8());
+			}
+		}
+	}
+
 	String root_uri = p_params["rootUri"];
 	String root = p_params["rootPath"];
 	bool is_same_workspace;

modules/gdscript/language_server/gdscript_workspace.cpp

@@ -559,16 +559,38 @@ Error GDScriptWorkspace::parse_local_script(const String &p_path) {
 }
 
 String GDScriptWorkspace::get_file_path(const String &p_uri) const {
-	String path = p_uri.uri_decode();
-	String base_uri = root_uri.uri_decode();
-	path = path.replacen(base_uri + "/", "res://");
-	return path;
+	int port;
+	String scheme, host, path, fragment;
+	p_uri.parse_url(scheme, host, port, path, fragment);
+
+	// TODO: Make the parsing RFC-3986 compliant.
+	if (scheme != "file" && scheme != "file:" && scheme != "file://") {
+		// The language server does only support the file protocol.
+		return "";
+	}
+
+	// Treat host like authority for now and ignore the port. It's an edge case for invalid file URI's anyway.
+	if (host != "" && host != "localhost") {
+		// The language server does not support nonlocal files.
+		return "";
+	}
+
+	// If query or fragment are present, the URI is not a valid file URI as per RFC-8089.
+	// We currently don't handle the query and it will be part of the path. However,
+	// this should not be a problem for a correct file URI.
+	if (fragment != "") {
+		return "";
+	}
+
+	String local_path = ProjectSettings::get_singleton()->localize_path(path.uri_decode());
+
+	return local_path;
 }
 
 String GDScriptWorkspace::get_file_uri(const String &p_path) const {
 	String uri = p_path;
-	uri = uri.replace("res://", root_uri + "/");
-	return uri;
+
+	return "file://" + ProjectSettings::get_singleton()->globalize_path(p_path).uri_encode();
 }
 
 void GDScriptWorkspace::publish_diagnostics(const String &p_path) {

modules/gdscript/language_server/godot_lsp.h

@@ -238,6 +238,25 @@ struct ReferenceContext {
 	bool includeDeclaration = false;
 };
 
+struct ShowMessageParams {
+	/**
+	 * The message type. See {@link MessageType}.
+	 */
+	int type;
+
+	/**
+	 * The actual message.
+	 */
+	String message;
+
+	_FORCE_INLINE_ Dictionary to_json() const {
+		Dictionary dict;
+		dict["type"] = type;
+		dict["message"] = message;
+		return dict;
+	}
+};
+
 struct ReferenceParams : TextDocumentPositionParams {
 	ReferenceContext context;
 };
@@ -405,6 +424,25 @@ static const int Full = 1;
 static const int Incremental = 2;
 }; // namespace TextDocumentSyncKind
 
+namespace MessageType {
+/**
+ * An error message.
+ */
+static const int Error = 1;
+/**
+ * A warning message.
+ */
+static const int Warning = 2;
+/**
+ * An information message.
+ */
+static const int Info = 3;
+/**
+ * A log message.
+ */
+static const int Log = 4;
+}; // namespace MessageType
+
 /**
  * Completion options.
  */