# VSCode Language Server - Node

This repository contains the code for the following npm modules:

* _vscode-languageclient_: npm module to talk to a VSCode language server from a VSCode extension:<br>
[![NPM Version](https://img.shields.io/npm/v/vscode-languageclient.svg)](https://npmjs.org/package/vscode-languageclient)
[![NPM Downloads](https://img.shields.io/npm/dm/vscode-languageclient.svg)](https://npmjs.org/package/vscode-languageclient)
* _vscode-languageserver_: npm module to implement a VSCode language server using [Node.js](https://nodejs.org/) as a runtime:<br>
[![NPM Version](https://img.shields.io/npm/v/vscode-languageserver.svg)](https://npmjs.org/package/vscode-languageserver)
[![NPM Downloads](https://img.shields.io/npm/dm/vscode-languageserver.svg)](https://npmjs.org/package/vscode-languageserver)
* _vscode-languageserver-textdocument_: npm module to implement text documents usable in a LSP server using [Node.js](https://nodejs.org/) as a runtime:<br>
[![NPM Version](https://img.shields.io/npm/v/vscode-languageserver-textdocument.svg)](https://npmjs.org/package/vscode-languageserver-textdocument)
[![NPM Downloads](https://img.shields.io/npm/dm/vscode-languageserver-textdocument.svg)](https://npmjs.org/package/vscode-languageserver-textdocument)
* _vscode-languageserver-protocol_: the actual language server protocol definition in TypeScript:<br>
[![NPM Version](https://img.shields.io/npm/v/vscode-languageserver-protocol.svg)](https://npmjs.org/package/vscode-languageserver-protocol)
[![NPM Downloads](https://img.shields.io/npm/dm/vscode-languageserver-protocol.svg)](https://npmjs.org/package/vscode-languageserver-protocol)
* _vscode-languageserver-types_: data types used by the language server client and server:<br>
[![NPM Version](https://img.shields.io/npm/v/vscode-languageserver-types.svg)](https://npmjs.org/package/vscode-languageserver-types)
[![NPM Downloads](https://img.shields.io/npm/dm/vscode-languageserver-types.svg)](https://npmjs.org/package/vscode-languageserver-types)
* _vscode-jsonrpc_: the underlying message protocol to communicate between a client and a server:<br>
[![NPM Version](https://img.shields.io/npm/v/vscode-jsonrpc.svg)](https://npmjs.org/package/vscode-jsonrpc)
[![NPM Downloads](https://img.shields.io/npm/dm/vscode-jsonrpc.svg)](https://npmjs.org/package/vscode-jsonrpc)

All four npm modules are built using one travis build. Its status is:

[![Build Status](https://travis-ci.org/Microsoft/vscode-languageserver-node.svg?branch=master)](https://travis-ci.org/Microsoft/vscode-languageserver-node)

Click [here](https://code.visualstudio.com/docs/extensions/example-language-server) for a detailed document on how to use these npm modules to implement
language servers for [VSCode](https://code.visualstudio.com/).

## Contributing

After cloning the repository, run `npm install` to install dependencies and `npm run symlink` to point packages in this repository to each other.

## History

## 3.17.4-next.0 Protocol, 8.2.0-next.0 JSON-RPC, 8.2.0-next.0 Client and 8.2.0-next.0 Server.

- middleware support for general notifications and requests as well as for register and unregister capabilities.
- various [bug fixes](https://github.com/microsoft/vscode-languageserver-node/milestone/46?closed=1).


## 3.17.3 Protocol, 8.1.0 JSON-RPC, 8.1.0 Client and 8.1.0 Server.

- support for custom message handlers
- various [bug fixes](https://github.com/microsoft/vscode-languageserver-node/milestone/49?closed=1). Noteworthy are fixes around request ordering problems with full document sync.

## 3.17.2 Protocol, 8.0.2 JSON-RPC, 8.0.2 Client and 8.0.2 Server.

- make client more robust against unwanted restarts
- added a LanguageClient#dispose method to fully dispose a client
- [various bug fixes](https://github.com/microsoft/vscode-languageserver-node/issues?q=is%3Aclosed+milestone%3A8.0.2).

## 3.17.0 Protocol, 8.0.0 JSON-RPC, 8.0.0 Client and 8.0.0 Server.

Library specific changes are:

- cleanup of client `start` and `stop` methods. Both methods now return a promise since these methods are async. This is a breaking change since start returned a disposable before. Extensions should now implement a deactivate function in their extension main file and correctly return the `stop` promise from the deactivate call. As a consequence the `onReady()` got removed since extensions can await the `start()` call now. Old code like this
```typescript
const client: LanguageClient = ...;
client.start();
await client.onReady();
```
should become:
```typescript
const client: LanguageClient = ...;
await client.start();
```
- notification and request handler registration can now happen before the client is started. This ensures that no messages from the server are missed.
- if an extension sends a notification or request before the client got started the client will auto start.
- all `sendNotification` methods now return a promise. Returning a promise was necessary since the actual writing of the message to the underlying transport is async and a client for example could not determine if a notification was handed off to the transport. This is a breaking change in the sense that it might result in floating promise and might be flagged by a linter.
- all handler registrations now return a Disposable to allow unregistration of the handler.
- the behavior of `handleFailedRequest` has change. Instead of returning a default value when a exception is received from the server the method now rethrows the error. This ensures that VS Code's default behavior on errors is used. The method also handles the `RequestCancelled` and `ServerCancelled` in the following way:
  - if it receives `ServerCancelled` and the client didn't cancel the request as well throw CancellationError to ask the client to rerun the request.
  - if it receives `RequestCancelled` then normally the client should have cancelled the request and the code will return the default value (according to the best interpretation of the 3.16 spec). If the client has not canceled interpret the `RequestCancelled` as `ServerCancelled`.
- the next handler of a client middleware now drops server results if the request got already canceled on the client side by returning VS Code's default value for the corresponding provider (mostly `null`). This is a breaking change since in former releases of the library the middleware would see the result also not used by VS Code. The change was made to save CPU and memory by not converting unused response results.
- all converter functions which take an array are now async, yield and take a cancellation token. This is a breaking change and got introduced to avoid monopolizing the extension host during type conversions.
- the return type of ErrorHandler#error and ErrorHandler#closed changed in a breaking manner. It now supports return an optional message which will be displayed to the user.
- Added support for inline values.
- Added support for inlay hints.
- Added support for type hierarchies.
- Added support for notebook documents.

## 3.16.0 Protocol, 6.0.0 JSON-RPC, 7.0.0 Client and 7.0.0 Server.

For a detailed list of changes made in the 3.16.0 version of the protocol see the [change log](https://microsoft.github.io/language-server-protocol/specifications/specification-3-16/#version_3_16_0) of the 3.16 specification.

Library specific changes are:

* cleanup of Request and Notification types. Removed the unnecessary generic parameter RO. This is a breaking change. To adapt simply remove the type argument.
* added the new concept of a RegistrationType which decouple the registration method from the actual request or notification method. This is a breaking change for implementors of custom features. To adapt rename the `messages` property to `registrationType` and return a corresponding `RegistrationType`. Additional remove the first parameter from the `register` method.
* cleanup of `ErrorCodes`. LSP specific error codes got moved to a new namespace `LSPErrorCodes`. The namespace `ErrorCodes` in `jsonrpc` is not correctly reserved for JSON RPC specific error codes. This is a breaking change. To resolve it use `LSPErrorCodes` instead.
* split code into common, node and browser to allow using the LSP client and server npm modules in a Web browser via webpack. This is a **breaking change** and might lead to compile / runtime errors if not adopted. Every module has now three different exports which represent the split into common, node and browser. Lets look at `vscode-jsonrpc` for an example: (a) the import `vscode-jsonrpc` will only import the common code, (b) the import `vscode-jsonrpc\node` will import the common and the node code and (c) the import `vscode-jsonrpc\browser` will import the common and browser code.
* added support to control the [parameter structure](https://www.jsonrpc.org/specification#parameter_structures) when sending requests and notifications in `vscode-jsonrpc`. The parameter structure can be controlled using the additional `parameterStructures` argument when creating a request or notification type or when sending an untyped request or notification using the `sendRequest` or `sendNotification` function. The default is `ParameterStructures.auto` which does the following:
  * use `byPosition` for messages with zero or greater than one parameter
  * for one parameter it used `byName` for parameters which are object literals. Uses `byPosition` for all other parameters.


## 3.15.3 Protocol, 6.1.x client and 6.1.x server

* Small changes to the proposed support for semantic tokens.

## 3.15.2 Protocol, 6.1.x client and 6.1.x server

* Proposed support for semantic tokens.

## 3.15.0 Protocol, 6.0.0 Client & 6.0.0 Server

* Progress support for work done and partial result progress.
* Proposed implementation for call hierarchies.
* `SelectionRangeRequest` protocol added:
  * New APIs in Types: `SelectionRange`
  * New APIs in Protocol: `SelectionRangeRequest`, `SelectionRangeParams`, `SelectionRangeClientCapabilities`, `SelectionRangeServerCapabilities`, `SelectionRangeProviderOptions`,
* Support for custom text document implementations:
  * new npm package `vscode-languageserver-textdocument` which ships a standard text document implementation with basic incremental update. Server now need to pre-requisite this npm package.
  * deprecated text document implementation in types.
  * this resulted in a small breakage on the server side. Instead of doing `new TextDocuments` you now have to pass in a text document configuration to provide callbacks to create and update a text document. Here are examples in TypeScript and JavaScript

```ts
import { TextDocuments } from 'vscode-languageserver';
import { TextDocument } from 'vscode-languageserver-textdocument';
const documents = new TextDocuments(TextDocument);
```

```js
const server = require("vscode-languageserver");
const textDocument = require("vscode-languageserver-textdocument");
const documents = new server.TextDocuments(textDocument.TextDocument);
```

### 5.1.1 Client

* Fixes [[textDocument/rename] client doesn't obey `RenameOptions` while registering provider](https://github.com/Microsoft/vscode-languageserver-node/issues/416)

### 5.1.0 Client & 5.1.0 Server

* Adopt protocol version 3.13.0

### 3.13.0 Protocol

* `FoldingRangeRequestParam` renamed to 'FoldingRangeParams' (`FoldingRangeRequestParam` still provided for backward compatibility)
* Added support for create, rename and delete file operations in workspace edits.

### 5.0.0 Client & 5.0.0 Server

* Make the client work with Electron 2.x. which is used since VS Code 1.26.x
* Check that the expected client version specified in `engines.vscode` in the `package.json` file matches the VS Code version the client is running on.

### 4.4.0 Client & 4.4.0 Server & 3.10.0 Protocol

* [Implement hierarchical document outline](https://github.com/Microsoft/vscode-languageserver-node/issues/373)
* `Color`, `ColorInformation`, `ColorPresentation` moved to Types
* `FoldingRangeRequest` protocol added:
  * New APIs in Types: `FoldingRange`, `FoldingRangeKind`
  * New APIs in Protocol: `FoldingRangeRequest`, `FoldingRangeRequestParam`, `FoldingRangeClientCapabilities`, `FoldingRangeServerCapabilities`, `FoldingRangeProviderOptions`,

### 4.3.0 Client & 4.3.0 Server & 3.9.0 Protocol

* Add support for `preselect` property on `CompletionItem`

### 4.2.0 Client & 4.2.0 Server & 3.8.0 Protocol

* [Add CodeAction class](https://github.com/Microsoft/language-server-protocol/issues/389)
* [Add support for code action literal as a return value of the textDocument/codeAction request ](https://github.com/Microsoft/vscode-languageserver-node/pull/350)

### 4.1.4 Client & 4.1.3 Server

* [Client: duplicate messages sent after server restart](https://github.com/Microsoft/vscode-languageserver-node/issues/342)

### 4.1.1 Client

* [Information on server crash lost as output channel is closed](https://github.com/Microsoft/vscode-languageserver-node/issues/319)

### 4.1.0 Client & Server

* Add support for related information in diagnostics.

* [Initialization exceptions swallowed](https://github.com/Microsoft/vscode-languageserver-node/issues/330)
* [Errors from rename still not shown in VSCode](https://github.com/Microsoft/vscode-languageserver-node/issues/329)
* [terminateProcess.sh is not shipped in dist package](https://github.com/Microsoft/vscode-languageserver-node/issues/331)
* [Add middleware to intercept textDocument/publishDiagnostics](https://github.com/Microsoft/vscode-languageserver-node/pull/322)

### 4.0.1 Client

* removed unnecessary console log statement.

### 4.0.0 Server and Client

* implemented the latest protocol additions. Noteworthy are completion context, extensible completion item and symbol kind as well as markdown support for completion item and signature help. Moved to 4.0.0 version since the introduction of the completion context required a breaking change in the client middleware. The old signature:
```ts
provideCompletionItem?: (this: void, document: TextDocument, position: VPosition, token: CancellationToken, next: ProvideCompletionItemsSignature) => ProviderResult<VCompletionItem[] | VCompletionList>;
```
contains now an additional argument `context`:
```ts
provideCompletionItem?: (this: void, document: TextDocument, position: VPosition, context: VCompletionContext, token: CancellationToken, next: ProvideCompletionItemsSignature) => ProviderResult<VCompletionItem[] | VCompletionList>;
```

* Noteworthy fixes:
  * [Getting value after executing command programmatically](https://github.com/Microsoft/language-server-protocol/issues/329)
  * [Experiencing infinite recursion in this code in VSCode 1.18.1](https://github.com/Microsoft/language-server-protocol/issues/279)
  * [LanguageClient#handleConnectionClosed fails to restart if this._resolvedConnection.dispose() throws](https://github.com/Microsoft/vscode-languageserver-node/issues/286)

### 6.0.0 Server and Client

* Move to Protocol 3.15.0
* move JS target to ES2017

### 3.15.0 Types and Protocol

* Implement LSP 3.15.0

### 3.6.1 Types
* ESM added as output format (for Webpack and other ESM consumers)

### 3.5.0 Server and Client

* allow the client to start the server in detached mode. If the server is running detached the client will not monitor the server process and kill it on shutdown.
* bug fixing.

### 3.4.0 Server and Client

* a new npm module `vscode-languageserver-protocol` has been added which contains the protocol definitions in TypeScript. This module is now shared between the client and the server.
* support for proposed protocol has been added to the `protocol`, `client` and `server` npm modules. Proposed protocol is subject to change even if it ships in a stable version of the npm modules.
* proposed protocol has been added for the following features:
  * _configuration_: support to fetch configuration settings by sending a request from the server to the client
  * _workspaceFolders_: support to handle more than one root folder per workspace
  * _colorProvider_: support to compute color ranges for a document

### 3.3.0 Server and Client

* splitted the client into a base client and a main client to support reusing the client implementation in other environments.
* made the request processing more async. So instead of processing a request immediately when the code gets notified by a Node.js callback the request is now put into a queue and processed from the queue. This allows for better dropping or folding of events if necessary.
* bugs fixes see [April](https://github.com/Microsoft/vscode-languageserver-node/issues?q=is%3Aissue+milestone%3A%22April+2017%22+is%3Aclosed) and [May](https://github.com/Microsoft/vscode-languageserver-node/issues?q=is%3Aissue+is%3Aclosed+milestone%3A%22Mai+2017%22)

### 3.2.1 Server and Client

* Fixed [Using wrong name for method `client/registerFeature`: should be `client/registerCapability`](https://github.com/Microsoft/vscode-languageserver-node/issues/199)

### 3.2.0 Server and Client

* made `WorkspaceEdit` conform to the 3.x version of the spec and backwards compatible with 2.x version of the library.
* added `RequestCancelled` error code.
* Fixed [nodePath not working (vscode-tslint)](https://github.com/Microsoft/vscode-languageserver-node/issues/179)
* Fixed [update from 3.0.4/3.0.5 to 3.1.0 breaks my extension](https://github.com/Microsoft/vscode-languageserver-node/issues/178)


### 3.1.0 Server and Client

* add support for named pipes and socket file transport
* fixed dead lock problem with node-ipc.

### 3.0.5 Server and 3.0.4 Client

* deprecated `Files.uriToFilePath` in favour of the vscode-uri npm module which provides a more complete implementation of URI for VS Code.
* made `rootPath` optional since it is deprecated in 3.x.

### 3.0.3: Client, Server and JSON-RPC

#### New Features

* Moved all libraries to TypeScript 2.x.x
* Client and Server are compiled to ES6. JSON-RPC is still compiled to ES5.
* JSON-RPC supports n parameter request and notification invocation.
* Support for the 3.0 version of the [Language Server protocol](https://github.com/Microsoft/language-server-protocol). Some highlights are:
  * Support for feature flags.
  * Support for dynamic registration. In the 2.x version of the library a server announced its capabilities statically. In 3.x the server
    can now dynamically register and un-register capability handlers using the new requests `client/registerCapability` and `client/unregisterCapability`.
  * Support to delegate command execution via a new request `workspace/executeCommand` to the server.
* Support for snippets in completion items:
  * New type `InsertTextFormat`
  * CompletionItem.insertTextFormat controls whether the inserted test is interpreted as a plain text or a snippet.

#### Breaking changes:
* to ensure ordered delivery of notifications and requests the language client now throws if sendRequest, onRequest, sendNotification or onNotification is called before the client is ready. Use the onReady() Promise to wait until the client is ready.

```ts
let client = new LanguageClient(...);
client.onReady().then(() => {
  client.onNotification(...);
  client.sendRequest(...);
);
```
* removed the deprecated module functions on code2Protocol and protocol2Code converters. Use the corresponding properties on the LanguageClient instance instead to get access to the same converters used by the LanguageClient.

```ts
// Old
import { Protocol2Code, ... } from 'vscode-languageclient';
Protocol2Code.asTextEdits(edits);
// New
let client = new LanguageClient(...);
client.protocol2CodeConverter.asTextEdits(edits);
```
* due to the use of TypeScript 2.x.x and differences in d.ts generation users of the new version need to move to TypeScript 2.x.x as well. Usually the `LanguageClient` is used in a VS Code extension. You can find detailed steps on how to upgrade a VS Code extension to TypeScript 2.x.x [here](http://code.visualstudio.com/updates/v1_6#_authoring-in-typescript).
* `activeSignature` and `activeParameter` where incorrectly declared as optional in `SignatureHelp`. They are now mandatory.
* the `protocol.ts` file used enum types in 2.x. However the protocol itself is number based since no assumption can be made about the presence of an enum type  in the implementing language. To make this more clear the enum got replace by number types with a or literal type definition. This might result in compile errors if a number was directly assigned to a previous enum type without a proper range check.
* Request and Notification types are now classes instead of interfaces. In addition they now take an additional type argument to type the registration options for dynamic registration. Adopting to that change is quite easy. Simply new the `RequestType` or `NotificationType` and add void as the registration option type. Please remember to update this on both the client and server side:

```ts
// Old
export namespace MyRequest {
  export const type: RequestType<MyParams, MyResult, void> = { get method() { return 'myRequest'; } };
}
export namespace MyNotification {
  export const type: NotificationType<MyParams> = { get method() { return 'myNotification'; } };
}
// New
export namespace MyRequest {
  export const type = new RequestType<MyParams, MyResult, void, void>('myRequest');
}
export namespace MyNotification {
  export const type = new NotificationType<MyParams, void>('myNotification');
}
```

### 2.6.0: Client and server

* Support for Document Link Providers
* Support for additional text edits and commands in completion items.

### 2.5.0: Client and Server

* Better error handling on client side.
* Events for starting and stopping the server.
* Initialization options can be provided as a function.
* Support for stdio / stderr encoding.
* Support to convert URIs between the client and the server.
* Server connection.console logging now appears in the corresponding output channel instead of in the developer console.
* If a non stdio communication channel is used between client and server the server's stdio is redirected to the output channel.
* A client can now have an id and a name.

### 2.4.0 Client and Server

* Data types such as Range, Position, TextDocument, Hover, CompletionItem... extracted to new node module _vscode-languageserver-types_. The new node module is shared between the server and client and can also be used by language service libraries that want to use the same data types.

### 2.3.0: Client only

* the client now restarts the server if the server crashes without a prior exit notification sent. The strategy used to restart the server is plugable (see `LanguageClientOptions.errorHandler`). The default strategy restart the server unless it crashed 5 times or more in the last 3 minutes.

### 2.0: A detailed description of the 2.0 version can be found [here](https://github.com/Microsoft/vscode-languageserver-protocol/blob/master/README.md). A summary of the changes:

* support for request cancellation. Cancellation is automatically hooked to VSCode's cancellation tokens
* document save notification.
* Synced text documents carry VSCode's text document version number

### 1.1.x: Provides all language service feature available in the extension host via the language client / server protocol. Features added:

* Code Actions: provide actions to fix diagnostic problems.
* Code Lens: provide commands that are shown along with source text.
* Formatting: whole document, document ranges and formatting on type.
* Rename refactoring: provides renaming symbols.

### 1.0.x: Version which provides support for the following features:

* Transports: stdio and node IPC can be used as a transport.
* Document synchronization: incremental and full text document synchronization.
* Configuration synchronization: synchronization of configuration settings to the server.
* File events: synchronization of file events to the server.
* Code Complete: provides code complete lists.
* Document Highlights: highlights all 'equal' symbols in a text document.
* Hover: provides hover information for a symbol selected in a text document.
* Signature Help: provides signature help for a symbol selected in a text document.
* Goto Definition: provides goto definition support for a symbol selected in a text document.
* Find References: finds all project-wide references for a symbol selected in a text document.
* List Document Symbols: lists all symbols defined in a text document.
* List Workspace Symbols: lists all project-wide symbols.

### 0.10.x: Initial versions to build a good API for the client and server side


## License
[MIT](https://github.com/Microsoft/vscode-languageserver-node/blob/master/License.txt)