Added null check to some adapters and changed type definition

lib/adapters/code-action-adapter.ts

@@ -47,7 +47,7 @@ export default class CodeActionAdapter {
 
     const params = CodeActionAdapter.createCodeActionParams(linterAdapter, editor, range, diagnostics)
     const actions = await connection.codeAction(params)
-    return actions.map((action) => CodeActionAdapter.createCodeAction(action, connection))
+    return (actions || []).map((action) => CodeActionAdapter.createCodeAction(action, connection))
   }
 
   private static createCodeAction(

lib/adapters/code-highlight-adapter.ts

@@ -27,6 +27,9 @@ export default class CodeHighlightAdapter {
   ): Promise<Range[] | null> {
     assert(serverCapabilities.documentHighlightProvider, "Must have the documentHighlight capability")
     const highlights = await connection.documentHighlight(Convert.editorToTextDocumentPositionParams(editor, position))
+    if (!highlights) {
+      return null
+    }
     return highlights.map((highlight) => {
       return Convert.lsRangeToAtomRange(highlight.range)
     })

lib/adapters/outline-view-adapter.ts

@@ -38,7 +38,7 @@ export default class OutlineViewAdapter {
       connection.documentSymbol({ textDocument: Convert.editorToTextDocumentIdentifier(editor) }, cancellationToken)
     )
 
-    if (results.length === 0) {
+    if (!results || results.length === 0) {
       return {
         outlineTrees: [],
       }

lib/auto-languageclient.ts

@@ -935,7 +935,7 @@ export default class AutoLanguageClient {
    * `didChangeWatchedFiles` message filtering, override for custom logic.
    *
    * @param filePath Path of a file that has changed in the project path
-   * @returns  `false` => message will not be sent to the language server
+   * @returns `false` => message will not be sent to the language server
    */
   protected filterChangeWatchedFiles(_filePath: string): boolean {
     return true

lib/languageclient.ts

@@ -72,22 +72,22 @@ export class LanguageClientConnection extends EventEmitter {
    * @returns A {Promise} containing the {InitializeResult} with details of the server's capabilities.
    */
   public initialize(params: lsp.InitializeParams): Promise<lsp.InitializeResult> {
-    return this._sendRequest("initialize", params)
+    return this._sendRequest(lsp.InitializeRequest.type, params)
   }
 
   /** Public: Send an `initialized` notification to the language server. */
   public initialized(): void {
-    this._sendNotification("initialized", {})
+    this._sendNotification(lsp.InitializedNotification.type, {})
   }
 
   /** Public: Send a `shutdown` request to the language server. */
   public shutdown(): Promise<void> {
-    return this._sendRequest("shutdown")
+    return this._sendRequest(lsp.ShutdownRequest.type)
   }
 
   /** Public: Send an `exit` notification to the language server. */
   public exit(): void {
-    this._sendNotification("exit")
+    this._sendNotification(lsp.ExitNotification.type)
   }
 
   /**
@@ -126,8 +126,8 @@ export class LanguageClientConnection extends EventEmitter {
    * @param method A string containing the name of the request message.
    * @param params The method's parameters
    */
-  public sendCustomRequest(method: string, params?: any[] | object): Promise<any | null> {
-    return this._sendRequest(method, params)
+  public sendCustomRequest(method: string, params?: any[] | object): Promise<any> {
+    return this._sendRequest(new lsp.ProtocolRequestType<typeof params, any, any, void, any>(method), params)
   }
 
   /**
@@ -137,7 +137,7 @@ export class LanguageClientConnection extends EventEmitter {
    * @param params The method's parameters
    */
   public sendCustomNotification(method: string, params?: any[] | object): void {
-    this._sendNotification(method, params)
+    this._sendNotification(new lsp.ProtocolNotificationType<typeof params, any>(method), params)
   }
 
   /**
@@ -212,7 +212,7 @@ export class LanguageClientConnection extends EventEmitter {
    * @param params The {DidChangeConfigurationParams} containing the new configuration.
    */
   public didChangeConfiguration(params: lsp.DidChangeConfigurationParams): void {
-    this._sendNotification("workspace/didChangeConfiguration", params)
+    this._sendNotification(lsp.DidChangeConfigurationNotification.type, params)
   }
 
   /**
@@ -221,7 +221,7 @@ export class LanguageClientConnection extends EventEmitter {
    * @param params The {DidOpenTextDocumentParams} containing the opened text document details.
    */
   public didOpenTextDocument(params: lsp.DidOpenTextDocumentParams): void {
-    this._sendNotification("textDocument/didOpen", params)
+    this._sendNotification(lsp.DidOpenTextDocumentNotification.type, params)
   }
 
   /**
@@ -231,7 +231,7 @@ export class LanguageClientConnection extends EventEmitter {
    *   number and actual text changes.
    */
   public didChangeTextDocument(params: lsp.DidChangeTextDocumentParams): void {
-    this._sendNotification("textDocument/didChange", params)
+    this._sendNotification(lsp.DidChangeTextDocumentNotification.type, params)
   }
 
   /**
@@ -240,7 +240,7 @@ export class LanguageClientConnection extends EventEmitter {
    * @param params The {DidCloseTextDocumentParams} containing the opened text document details.
    */
   public didCloseTextDocument(params: lsp.DidCloseTextDocumentParams): void {
-    this._sendNotification("textDocument/didClose", params)
+    this._sendNotification(lsp.DidCloseTextDocumentNotification.type, params)
   }
 
   /**
@@ -249,7 +249,7 @@ export class LanguageClientConnection extends EventEmitter {
    * @param params The {WillSaveTextDocumentParams} containing the to-be-saved text document details and the reason for the save.
    */
   public willSaveTextDocument(params: lsp.WillSaveTextDocumentParams): void {
-    this._sendNotification("textDocument/willSave", params)
+    this._sendNotification(lsp.WillSaveTextDocumentNotification.type, params)
   }
 
   /**
@@ -259,7 +259,7 @@ export class LanguageClientConnection extends EventEmitter {
    * @returns A {Promise} containing an {Array} of {TextEdit}s to be applied to the text document before it is saved.
    */
   public willSaveWaitUntilTextDocument(params: lsp.WillSaveTextDocumentParams): Promise<lsp.TextEdit[] | null> {
-    return this._sendRequest("textDocument/willSaveWaitUntil", params)
+    return this._sendRequest(lsp.WillSaveTextDocumentWaitUntilRequest.type, params)
   }
 
   /**
@@ -268,7 +268,7 @@ export class LanguageClientConnection extends EventEmitter {
    * @param params The {DidSaveTextDocumentParams} containing the saved text document details.
    */
   public didSaveTextDocument(params: lsp.DidSaveTextDocumentParams): void {
-    this._sendNotification("textDocument/didSave", params)
+    this._sendNotification(lsp.DidSaveTextDocumentNotification.type, params)
   }
 
   /**
@@ -278,7 +278,7 @@ export class LanguageClientConnection extends EventEmitter {
    *   the watched files.
    */
   public didChangeWatchedFiles(params: lsp.DidChangeWatchedFilesParams): void {
-    this._sendNotification("workspace/didChangeWatchedFiles", params)
+    this._sendNotification(lsp.DidChangeWatchedFilesNotification.type, params)
   }
 
   /**
@@ -303,7 +303,7 @@ export class LanguageClientConnection extends EventEmitter {
     cancellationToken?: jsonrpc.CancellationToken
   ): Promise<lsp.CompletionItem[] | lsp.CompletionList | null> {
     // Cancel prior request if necessary
-    return this._sendRequest("textDocument/completion", params, cancellationToken)
+    return this._sendRequest(lsp.CompletionRequest.type, params, cancellationToken)
   }
 
   /**
@@ -312,8 +312,8 @@ export class LanguageClientConnection extends EventEmitter {
    * @param params The {CompletionItem} for which a fully resolved {CompletionItem} is desired.
    * @returns A {Promise} containing a fully resolved {CompletionItem}.
    */
-  public completionItemResolve(params: lsp.CompletionItem): Promise<lsp.CompletionItem | null> {
-    return this._sendRequest("completionItem/resolve", params)
+  public completionItemResolve(params: lsp.CompletionItem): Promise<lsp.CompletionItem> {
+    return this._sendRequest(lsp.CompletionResolveRequest.type, params)
   }
 
   /**
@@ -323,7 +323,7 @@ export class LanguageClientConnection extends EventEmitter {
    * @returns A {Promise} containing a {Hover}.
    */
   public hover(params: lsp.TextDocumentPositionParams): Promise<lsp.Hover | null> {
-    return this._sendRequest("textDocument/hover", params)
+    return this._sendRequest(lsp.HoverRequest.type, params)
   }
 
   /**
@@ -333,7 +333,7 @@ export class LanguageClientConnection extends EventEmitter {
    * @returns A {Promise} containing a {SignatureHelp}.
    */
   public signatureHelp(params: lsp.TextDocumentPositionParams): Promise<lsp.SignatureHelp | null> {
-    return this._sendRequest("textDocument/signatureHelp", params)
+    return this._sendRequest(lsp.SignatureHelpRequest.type, params)
   }
 
   /**
@@ -346,7 +346,7 @@ export class LanguageClientConnection extends EventEmitter {
   public gotoDefinition(
     params: lsp.TextDocumentPositionParams
   ): Promise<lsp.Location | lsp.Location[] | lsp.LocationLink[] | null> {
-    return this._sendRequest("textDocument/definition", params)
+    return this._sendRequest(lsp.DefinitionRequest.type, params)
   }
 
   /**
@@ -355,8 +355,8 @@ export class LanguageClientConnection extends EventEmitter {
    * @param params The {TextDocumentPositionParams} of a symbol for which all referring {Location}s are desired.
    * @returns A {Promise} containing an {Array} of {Location}s that reference this symbol.
    */
-  public findReferences(params: lsp.ReferenceParams): Promise<lsp.Location[]> {
-    return this._sendRequest("textDocument/references", params)
+  public findReferences(params: lsp.ReferenceParams): Promise<lsp.Location[] | null> {
+    return this._sendRequest(lsp.ReferencesRequest.type, params)
   }
 
   /**
@@ -365,8 +365,8 @@ export class LanguageClientConnection extends EventEmitter {
    * @param params The {TextDocumentPositionParams} of a symbol for which all highlights are desired.
    * @returns A {Promise} containing an {Array} of {DocumentHighlight}s that can be used to highlight this symbol.
    */
-  public documentHighlight(params: lsp.TextDocumentPositionParams): Promise<lsp.DocumentHighlight[]> {
-    return this._sendRequest("textDocument/documentHighlight", params)
+  public documentHighlight(params: lsp.TextDocumentPositionParams): Promise<lsp.DocumentHighlight[] | null> {
+    return this._sendRequest(lsp.DocumentHighlightRequest.type, params)
   }
 
   /**
@@ -379,8 +379,8 @@ export class LanguageClientConnection extends EventEmitter {
   public documentSymbol(
     params: lsp.DocumentSymbolParams,
     _cancellationToken?: jsonrpc.CancellationToken
-  ): Promise<lsp.SymbolInformation[] | lsp.DocumentSymbol[]> {
-    return this._sendRequest("textDocument/documentSymbol", params)
+  ): Promise<lsp.SymbolInformation[] | lsp.DocumentSymbol[] | null> {
+    return this._sendRequest(lsp.DocumentSymbolRequest.type, params)
   }
 
   /**
@@ -390,8 +390,8 @@ export class LanguageClientConnection extends EventEmitter {
    * @returns A {Promise} containing an {Array} of {SymbolInformation}s that identify where the query string occurs
    *   within the workspace.
    */
-  public workspaceSymbol(params: lsp.WorkspaceSymbolParams): Promise<lsp.SymbolInformation[]> {
-    return this._sendRequest("workspace/symbol", params)
+  public workspaceSymbol(params: lsp.WorkspaceSymbolParams): Promise<lsp.SymbolInformation[] | null> {
+    return this._sendRequest(lsp.WorkspaceSymbolRequest.type, params)
   }
 
   /**
@@ -400,8 +400,8 @@ export class LanguageClientConnection extends EventEmitter {
    * @param params The {CodeActionParams} identifying the document, range and context for the code action.
    * @returns A {Promise} containing an {Array} of {Commands}s that can be performed against the given documents range.
    */
-  public codeAction(params: lsp.CodeActionParams): Promise<Array<lsp.Command | lsp.CodeAction>> {
-    return this._sendRequest("textDocument/codeAction", params)
+  public codeAction(params: lsp.CodeActionParams): Promise<Array<lsp.Command | lsp.CodeAction> | null> {
+    return this._sendRequest(lsp.CodeActionRequest.type, params)
   }
 
   /**
@@ -411,8 +411,8 @@ export class LanguageClientConnection extends EventEmitter {
    * @returns A {Promise} containing an {Array} of {CodeLens}s that associate commands and data with specified ranges
    *   within the document.
    */
-  public codeLens(params: lsp.CodeLensParams): Promise<lsp.CodeLens[]> {
-    return this._sendRequest("textDocument/codeLens", params)
+  public codeLens(params: lsp.CodeLensParams): Promise<lsp.CodeLens[] | null> {
+    return this._sendRequest(lsp.CodeLensRequest.type, params)
   }
 
   /**
@@ -421,8 +421,8 @@ export class LanguageClientConnection extends EventEmitter {
    * @param params The {CodeLens} identifying the code lens to be resolved with full detail.
    * @returns A {Promise} containing the {CodeLens} fully resolved.
    */
-  public codeLensResolve(params: lsp.CodeLens): Promise<lsp.CodeLens | null> {
-    return this._sendRequest("codeLens/resolve", params)
+  public codeLensResolve(params: lsp.CodeLens): Promise<lsp.CodeLens> {
+    return this._sendRequest(lsp.CodeLensResolveRequest.type, params)
   }
 
   /**
@@ -431,8 +431,8 @@ export class LanguageClientConnection extends EventEmitter {
    * @param params The {DocumentLinkParams} identifying the document for which links should be identified.
    * @returns A {Promise} containing an {Array} of {DocumentLink}s relating uri's to specific ranges within the document.
    */
-  public documentLink(params: lsp.DocumentLinkParams): Promise<lsp.DocumentLink[]> {
-    return this._sendRequest("textDocument/documentLink", params)
+  public documentLink(params: lsp.DocumentLinkParams): Promise<lsp.DocumentLink[] | null> {
+    return this._sendRequest(lsp.DocumentLinkRequest.type, params)
   }
 
   /**
@@ -442,7 +442,7 @@ export class LanguageClientConnection extends EventEmitter {
    * @returns A {Promise} containing the {DocumentLink} fully resolved.
    */
   public documentLinkResolve(params: lsp.DocumentLink): Promise<lsp.DocumentLink> {
-    return this._sendRequest("documentLink/resolve", params)
+    return this._sendRequest(lsp.DocumentLinkResolveRequest.type, params)
   }
 
   /**
@@ -452,8 +452,8 @@ export class LanguageClientConnection extends EventEmitter {
    *   formatting preferences.
    * @returns A {Promise} containing an {Array} of {TextEdit}s to be applied to the document to correctly reformat it.
    */
-  public documentFormatting(params: lsp.DocumentFormattingParams): Promise<lsp.TextEdit[]> {
-    return this._sendRequest("textDocument/formatting", params)
+  public documentFormatting(params: lsp.DocumentFormattingParams): Promise<lsp.TextEdit[] | null> {
+    return this._sendRequest(lsp.DocumentFormattingRequest.type, params)
   }
 
   /**
@@ -463,8 +463,8 @@ export class LanguageClientConnection extends EventEmitter {
    *   additional formatting preferences.
    * @returns A {Promise} containing an {Array} of {TextEdit}s to be applied to the document to correctly reformat it.
    */
-  public documentRangeFormatting(params: lsp.DocumentRangeFormattingParams): Promise<lsp.TextEdit[]> {
-    return this._sendRequest("textDocument/rangeFormatting", params)
+  public documentRangeFormatting(params: lsp.DocumentRangeFormattingParams): Promise<lsp.TextEdit[] | null> {
+    return this._sendRequest(lsp.DocumentRangeFormattingRequest.type, params)
   }
 
   /**
@@ -474,8 +474,8 @@ export class LanguageClientConnection extends EventEmitter {
    *   typed and at what position as well as additional formatting preferences.
    * @returns A {Promise} containing an {Array} of {TextEdit}s to be applied to the document to correctly reformat it.
    */
-  public documentOnTypeFormatting(params: lsp.DocumentOnTypeFormattingParams): Promise<lsp.TextEdit[]> {
-    return this._sendRequest("textDocument/onTypeFormatting", params)
+  public documentOnTypeFormatting(params: lsp.DocumentOnTypeFormattingParams): Promise<lsp.TextEdit[] | null> {
+    return this._sendRequest(lsp.DocumentOnTypeFormattingRequest.type, params)
   }
 
   /**
@@ -486,8 +486,8 @@ export class LanguageClientConnection extends EventEmitter {
    * @returns A {Promise} containing an {WorkspaceEdit} that contains a list of {TextEdit}s either on the changes
    *   property (keyed by uri) or the documentChanges property containing an {Array} of {TextDocumentEdit}s (preferred).
    */
-  public rename(params: lsp.RenameParams): Promise<lsp.WorkspaceEdit> {
-    return this._sendRequest("textDocument/rename", params)
+  public rename(params: lsp.RenameParams): Promise<lsp.WorkspaceEdit | null> {
+    return this._sendRequest(lsp.RenameRequest.type, params)
   }
 
   /**
@@ -498,7 +498,7 @@ export class LanguageClientConnection extends EventEmitter {
    * @returns A {Promise} containing anything.
    */
   public executeCommand(params: lsp.ExecuteCommandParams): Promise<any> {
-    return this._sendRequest("workspace/executeCommand", params)
+    return this._sendRequest(lsp.ExecuteCommandRequest.type, params)
   }
 
   private _onRequest<T extends Extract<keyof KnownRequests, string>>(
@@ -521,16 +521,21 @@ export class LanguageClientConnection extends EventEmitter {
     })
   }
 
-  private _sendNotification(method: string, args?: object): void {
+  private _sendNotification<P, RO>(
+    protocol: lsp.ProtocolNotificationType<P, RO> | lsp.ProtocolNotificationType0<RO>,
+    args?: P
+  ): void {
+    const { method } = protocol
     this._log.debug(`rpc.sendNotification ${method}`, args)
     this._rpc.sendNotification(method, args)
   }
 
-  private async _sendRequest(
-    method: string,
-    args?: object,
+  private async _sendRequest<P, R, PR, E, RO>(
+    protocol: lsp.ProtocolRequestType<P, R, PR, E, RO> | lsp.ProtocolRequestType0<R, PR, E, RO>,
+    args?: P,
     cancellationToken?: jsonrpc.CancellationToken
-  ): Promise<any> {
+  ): Promise<R> {
+    const { method } = protocol
     this._log.debug(`rpc.sendRequest ${method} sending`, args)
     try {
       const start = performance.now()
@@ -546,7 +551,7 @@ export class LanguageClientConnection extends EventEmitter {
 
       const took = performance.now() - start
       this._log.debug(`rpc.sendRequest ${method} received (${Math.floor(took)}ms)`, result)
-      return result
+      return result as R
     } catch (e) {
       const responseError = e as jsonrpc.ResponseError<any>
       if (cancellationToken && responseError.code === lsp.LSPErrorCodes.RequestCancelled) {