Repository files navigation

• What is it, exactly?
• Installing
• Running the language server
• CLI Options
• Configuration
• Features
  • Code actions on save
  • Workspace commands (workspace/executeCommand)
    • Go to Source Definition
    • Apply Refactoring
    • Organize Imports
    • Rename File
    • Send Tsserver Command
    • Configure plugin
  • Code Lenses (textDocument/codeLens)
  • Inlay hints (textDocument/inlayHint)
  • TypeScript Version Notification
  • Workspace Configuration request for formatting settings
• Development
  • Build
  • Dev
  • Test
  • Publishing

TheTypeScript project/package includes atsserver component which provides a custom API that can be used for gathering various intelligence about a typescript/javascript project. TheVSCode team has built a project calledTypescript Language Features (and bundled it as an internal extension in VSCode) that provides code intelligence for your javascript and typescript projects by utilizing thattsserver API. Since that extension doesn't use the standardizedLanguage Server Protocol to communicate with the editor, other editors that implement LSP can't directly utilize it. Here is where theTypeScript Language Server project comes in with the aim to provide a thin LSP interface on top of that extension's code base for the benefit of all other editors that implement the LSP protocol.

Originally based on concepts and ideas fromhttps://github.com/prabirshrestha/typescript-language-server and maintained byTypeFox. Currently maintained by acommunity of contributors like you.

This project is not directly associated with Microsoft and is not used in theirVSCode editor. If you have an issue with VSCode functionality, report it in their repository instead.

Currently Microsoft is working onTypeScript 7 written natively in the go language that will include the LSP implementation and will hopefully supersede this project.

npm install -g typescript-language-server typescript

typescript-language-server --stdio

  Usage: typescript-language-server [options]  Options:    -V, --version                          output the version number    --stdio                                use stdio (required option)    --log-level <log-level>                A number indicating the log level (4 = log, 3 = info, 2 = warn, 1 = error). Defaults to `3`.    -h, --help                             output usage information

Seeconfiguration documentation.

Server announces support for the following code action kinds:

• source.fixAll.ts - despite the name, fixes a couple of specific issues: unreachable code, await in non-async functions, incorrectly implemented interface
• source.removeUnused.ts - removes declared but unused variables
• source.addMissingImports.ts - adds imports for used but not imported symbols
• source.removeUnusedImports.ts - removes unused imports
• source.sortImports.ts - sorts imports
• source.organizeImports.ts - organizes and removes unused imports

This allows editors that support running code actions on save to automatically run fixes associated with those kinds.

Those code actions, if they apply in the current code, should also be presented in the list of "Source Actions" if the editor exposes those.

The user can enable it with a setting similar to (can vary per-editor):

"codeActionsOnSave":{"source.organizeImports.ts":true,// or just"source.organizeImports":true,}

SeeLSP specification.

Most of the time, you'll execute commands with arguments retrieved from another request liketextDocument/codeAction. There are some use cases for calling them manually.

lsp refers to the language server protocol types,tsp refers to the typescript server protocol types.

Request:

{    command:'_typescript.goToSourceDefinition'    arguments:[lsp.DocumentUri,// String URI of the documentlsp.Position,// Line and character position (zero-based)]}

Response:

lsp.Location[]|null

(This command is supported from Typescript 4.7.)

Request:

{    command:'_typescript.applyRefactoring'    arguments:[tsp.GetEditsForRefactorRequestArgs,]}

Response:

void

Request:

{    command:'_typescript.organizeImports'    arguments:[string,// file path// Optional options:{//@deprecated - use "mode". Supported from Typescript 4.4+.skipDestructiveCodeActions?: boolean// 'All' - organizes imports including destructive actions (removing unused imports)// 'SortAndCombine' - Doesn't perform destructive actions.// 'RemoveUnused' - Only removes unused imports.mode?:'All'|'SortAndCombine'|'RemoveUnused'},]}

Response:

void

Request:

{    command:'_typescript.applyRenameFile'    arguments:[{sourceUri:string; targetUri:string;},]}

Response:

void

Request:

{    command:'typescript.tsserverRequest'    arguments:[string,// commandany,// command arguments in a format that the command expectsExecuteInfo,// configuration object used for the tsserver request (see below)]}

Response:

any

TheExecuteInfo object is defined as follows:

typeExecuteInfo={executionTarget?:number;// 0 - semantic server, 1 - syntax server; default: 0expectsResult?:boolean;// default: trueisAsync?:boolean;// default: falselowPriority?:boolean;// default: true};

Request:

{    command:'_typescript.configurePlugin'    arguments:[pluginName: string,configuration: any]}

Response:

void

Code lenses can be enabled using theimplementationsCodeLens andreferencesCodeLensworkspace configuration options.

Code lenses provide a count ofreferences and/orimplemenations for symbols in the document. For clients that support it it's also possible to click on those to navigate to the relevant locations in the the project. Do note that clicking those trigger aeditor.action.showReferences command which is something that client needs to have explicit support for. Many do by default but some don't. An example command will look like this:

command:{title:'1 reference',command:'editor.action.showReferences',arguments:['file://project/foo.ts',// URI{line:1,character:1},// Position[// A list of Location objects.{uri:'file://project/bar.ts',range:{start:{line:7,character:24,},end:{line:7,character:28,},},},],],}

For the request to return any results, some or all of the following options need to be enabled throughpreferences:

exportinterfaceInlayHintsOptionsextendsUserPreferences{includeInlayParameterNameHints:'none'|'literals'|'all';includeInlayParameterNameHintsWhenArgumentMatchesName:boolean;includeInlayFunctionParameterTypeHints:boolean;includeInlayVariableTypeHints:boolean;includeInlayVariableTypeHintsWhenTypeMatchesName:boolean;includeInlayPropertyDeclarationTypeHints:boolean;includeInlayFunctionLikeReturnTypeHints:boolean;includeInlayEnumMemberValueHints:boolean;}

Right after initializing, the server sends a custom$/typescriptVersion notification that carries information about the version of TypeScript that is utilized by the server. The editor can then display that information in the UI.

The$/typescriptVersion notification params include two properties:

• version - a semantic version (for example4.8.4)
• source - a string specifying whether used TypeScript version comes from the local workspace (workspace), is explicitly specified through ainitializationOptions.tsserver.path setting (user-setting) or was bundled with the server (bundled)

Server asks the client for file-specific configuration options (tabSize andinsertSpaces) that are required bytsserver to properly format file edits when for example using "Organize imports" or performing other file modifications. Those options have to be dynamically provided by the client/editor since the values can differ for each file. For this reason server sends aworkspace/configuration request withscopeUri equal to file's URI andsection equal toformattingOptions. The client is expected to return a configuration that includes the following properties:

{"tabSize":number"insertSpaces":boolean}

yarn build

Build and rebuild on change.

yarn dev

• yarn test - run all tests in watch mode for developing
• yarn test:commit - run all tests once

By default only console logs of levelwarning and higher are printed to the console. You can override theCONSOLE_LOG_LEVEL level inpackage.json to eitherlog,info,warning orerror to log other levels.

The project useshttps://github.com/google-github-actions/release-please-action Github action to automatically release new version on merging a release PR.