feat: add handler for workspace will create files request

lsp_3_17/handler.go

@@ -91,6 +91,7 @@ type Handler struct {
 	workspaceSymbolResolve          WorkspaceSymbolResolveHandlerFunc
 	workspaceDidChangeConfiguration WorkspaceDidChangeConfigurationHandlerFunc
 	workspaceDidChangeFolders       WorkspaceDidChangeFoldersHandlerFunc
+	workspaceWillCreateFiles        WorkspaceWillCreateFilesHandlerFunc
 
 	isInitialized bool
 	// Provides a mapping of method names to the respective handlers

lsp_3_17/handler_workspace_features.go

@@ -34,6 +34,13 @@ func WithWorkspaceDidChangeFoldersHandler(handler WorkspaceDidChangeFoldersHandl
 	}
 }
 
+// WithWorkspaceWillCreateFilesHandler sets the handler for the `workspace/willCreateFiles` request.
+func WithWorkspaceWillCreateFilesHandler(handler WorkspaceWillCreateFilesHandlerFunc) HandlerOption {
+	return func(root *Handler) {
+		root.SetWorkspaceWillCreateFilesHandler(handler)
+	}
+}
+
 // SetWorkspaceSymbolHandler sets the handler for the `workspace/symbol` request.
 func (h *Handler) SetWorkspaceSymbolHandler(handler WorkspaceSymbolHandlerFunc) {
 	h.mu.Lock()
@@ -66,6 +73,14 @@ func (h *Handler) SetWorkspaceDidChangeFoldersHandler(handler WorkspaceDidChange
 	h.messageHandlers[MethodWorkspaceDidChangeFolders] = createWorkspaceDidChangeFoldersHandler(h)
 }
 
+// SetWorkspaceWillCreateFilesHandler sets the handler for the `workspace/willCreateFiles` request.
+func (h *Handler) SetWorkspaceWillCreateFilesHandler(handler WorkspaceWillCreateFilesHandlerFunc) {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	h.workspaceWillCreateFiles = handler
+	h.messageHandlers[MethodWorkspaceWillCreateFiles] = createWorkspaceWillCreateFilesHandler(h)
+}
+
 func createWorkspaceSymbolHandler(root *Handler) common.Handler {
 	return common.HandlerFunc(
 		func(
@@ -137,3 +152,21 @@ func createWorkspaceDidChangeFoldersHandler(root *Handler) common.Handler {
 		},
 	)
 }
+
+func createWorkspaceWillCreateFilesHandler(root *Handler) common.Handler {
+	return common.HandlerFunc(
+		func(
+			ctx *common.LSPContext,
+		) (r any, validMethod bool, validParams bool, err error) {
+			validMethod = true
+			if root.workspaceWillCreateFiles != nil {
+				var params CreateFilesParams
+				if err = json.Unmarshal(ctx.Params, &params); err == nil {
+					validParams = true
+					r, err = root.workspaceWillCreateFiles(ctx, &params)
+				}
+			}
+			return
+		},
+	)
+}

lsp_3_17/handler_workspace_features_test.go

@@ -229,3 +229,64 @@ func (s *HandlerTestSuite) Test_calls_workspace_did_change_folders_notification_
 		s.Require().Equal(didChangeFoldersParams, *receivedParams)
 	}
 }
+
+func (s *HandlerTestSuite) Test_calls_workspace_will_create_files_request_handler() {
+	logger, err := zap.NewDevelopment()
+	s.Require().NoError(err)
+
+	ctx, cancel := context.WithTimeout(context.Background(), server.DefaultTimeout)
+	defer cancel()
+
+	workspaceEdit := WorkspaceEdit{
+		Changes: map[string][]TextEdit{
+			"edit1": []TextEdit{
+				{
+					Range: &Range{
+						Start: Position{
+							Line:      1,
+							Character: 1,
+						},
+						End: Position{
+							Line:      1,
+							Character: 5,
+						},
+					},
+					NewText: "help",
+				},
+			},
+		},
+	}
+	serverHandler := NewHandler(
+		WithWorkspaceWillCreateFilesHandler(
+			func(ctx *common.LSPContext, params *CreateFilesParams) (*WorkspaceEdit, error) {
+				return &workspaceEdit, nil
+			},
+		),
+	)
+	// Emulate the LSP initialisation process.
+	serverHandler.SetInitialized(true)
+	srv := server.NewServer(serverHandler, true, nil, nil)
+
+	container := createTestConnectionsContainer(srv.NewHandler())
+
+	go srv.Serve(container.serverConn, logger)
+
+	clientLSPContext := server.NewLSPContext(ctx, container.clientConn, nil)
+
+	createFilesParams := &CreateFilesParams{
+		Files: []FileCreate{
+			{
+				URI: "file:///test_doc.go",
+			},
+		},
+	}
+
+	returnedEdit := WorkspaceEdit{}
+	err = clientLSPContext.Call(
+		MethodWorkspaceWillCreateFiles,
+		createFilesParams,
+		&returnedEdit,
+	)
+	s.Require().NoError(err)
+	s.Require().Equal(workspaceEdit, returnedEdit)
+}

lsp_3_17/workspaces.go

@@ -542,3 +542,31 @@ type WorkspaceFoldersChangeEvent struct {
 	// The array of removed workspace folders.
 	Removed []WorkspaceFolder `json:"removed"`
 }
+
+// https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#workspace_willCreateFiles
+
+const MethodWorkspaceWillCreateFiles = Method("workspace/willCreateFiles")
+
+// WorkspaceWillCreateFilesHandlerFunc is the function signature for the
+// `workspace/willCreateFiles` method.
+type WorkspaceWillCreateFilesHandlerFunc func(
+	context *common.LSPContext,
+	params *CreateFilesParams,
+) (*WorkspaceEdit, error)
+
+// CreateFilesParams contains the parameters sent in notifications/requests
+// for user-initiated creation of files.
+//
+// @since 3.16.0
+type CreateFilesParams struct {
+	// An array of all files/folders created in this operation.
+	Files []FileCreate `json:"files"`
+}
+
+// FileCreate represents information on a file/folder creation.
+//
+// @since 3.16.0
+type FileCreate struct {
+	// A file:// URI for the location of the file/folder being created.
+	URI string `json:"uri"`
+}