typescript-language-server
Advanced tools
Language Server Protocol (LSP) implementation for TypeScript using tsserver
The TypeScript project/package includes a tsserver component which provides a custom API that can be used for gathering various intelligence about a typescript/javascript project. The VSCode team has built a project called Typescript Language Features (and bundled it as an internal extension in VSCode) that provides code intelligence for your javascript and typescript projects by utilizing that tsserver API. Since that extension doesn't use the standardized Language Server Protocol to communicate with the editor, other editors that implement LSP can't directly utilize it. Here is where the TypeScript 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 from https://github.com/prabirshrestha/typescript-language-server and maintained by TypeFox. Currently maintained by a community of contributors like you.
This project is not directly associated with Microsoft and is not used in their VSCode editor. If you have an issue with VSCode functionality, report it in their repository instead.
Currently Microsoft is working on TypeScript 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
See configuration 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 interfacesource.removeUnused.ts - removes declared but unused variablessource.addMissingImports.ts - adds imports for used but not imported symbolssource.removeUnusedImports.ts - removes unused importssource.sortImports.ts - sorts importssource.organizeImports.ts - organizes and removes unused importsThis 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,
}
workspace/executeCommand)See LSP specification.
Most of the time, you'll execute commands with arguments retrieved from another request like textDocument/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.
{
command: `_typescript.goToSourceDefinition`
arguments: [
lsp.DocumentUri, // String URI of the document
lsp.Position, // Line and character position (zero-based)
]
}
lsp.Location[] | null
(This command is supported from Typescript 4.7.)
{
command: `_typescript.applyRefactoring`
arguments: [
tsp.GetEditsForRefactorRequestArgs,
]
}
void
{
command: `_typescript.organizeImports`
arguments: [
// The "skipDestructiveCodeActions" argument is supported from Typescript 4.4+
[string] | [string, { skipDestructiveCodeActions?: boolean }],
]
}
void
{
command: `_typescript.applyRenameFile`
arguments: [
{ sourceUri: string; targetUri: string; },
]
}
void
{
command: `typescript.tsserverRequest`
arguments: [
string, // command
any, // command arguments in a format that the command expects
ExecuteInfo, // configuration object used for the tsserver request (see below)
]
}
any
The ExecuteInfo object is defined as follows:
type ExecuteInfo = {
executionTarget?: number; // 0 - semantic server, 1 - syntax server; default: 0
expectsResult?: boolean; // default: true
isAsync?: boolean; // default: false
lowPriority?: boolean; // default: true
};
{
command: `_typescript.configurePlugin`
arguments: [pluginName: string, configuration: any]
}
void
textDocument/codeLens)Code lenses can be enabled using the implementationsCodeLens and referencesCodeLens workspace configuration options.
Code lenses provide a count of references and/or implemenations 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 a editor.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,
},
},
},
],
],
}
textDocument/inlayHint)For the request to return any results, some or all of the following options need to be enabled through preferences:
export interface InlayHintsOptions extends UserPreferences {
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 example 4.8.4)source - a string specifying whether used TypeScript version comes from the local workspace (workspace), is explicitly specified through a initializationOptions.tsserver.path setting (user-setting) or was bundled with the server (bundled)yarn build
Build and rebuild on change.
yarn dev
yarn test - run all tests in watch mode for developingyarn test:commit - run all tests onceBy default only console logs of level warning and higher are printed to the console. You can override the CONSOLE_LOG_LEVEL level in package.json to either log, info, warning or error to log other levels.
The project uses https://github.com/google-github-actions/release-please-action Github action to automatically release new version on merging a release PR.
The vscode-json-languageserver is a Language Server Protocol implementation for JSON. It provides similar functionalities like auto-completion, go-to-definition, and diagnostics but is specifically tailored for JSON files. Compared to typescript-language-server, it is focused on JSON rather than TypeScript.
The vscode-css-languageserver-bin is a Language Server Protocol implementation for CSS. It offers features like auto-completion, go-to-definition, and diagnostics for CSS files. While typescript-language-server is for TypeScript, this package is specialized for CSS.
The vscode-html-languageserver-bin is a Language Server Protocol implementation for HTML. It provides functionalities such as auto-completion, go-to-definition, and diagnostics for HTML files. This package is similar to typescript-language-server but is designed for HTML.
FAQs
Language Server Protocol (LSP) implementation for TypeScript using tsserver
The npm package typescript-language-server receives a total of 1,311,651 weekly downloads. As such, typescript-language-server popularity was classified as popular.
We found that typescript-language-server demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 3 open source maintainers collaborating on the project.
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