refactor: ship as an ES module (#547)

BREAKING CHANGE: Ship as an ES module. Might be breaking for programmatic users of this server. Read more about consuming ES module packages at gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c

.mocharc.yaml

@@ -2,6 +2,9 @@ require:
     - 'source-map-support/register'
     - 'ts-node/register'
 spec: './src/**/*.spec.ts'
+node-option:
+    - 'experimental-specifier-resolution=node'
+    - 'loader=ts-node/esm'
 # Set to 0 to disable timeout when debugging.
 timeout: 20000
 watch-files: './src/**/*.ts'

package.json

@@ -4,16 +4,14 @@
   "description": "Language Server Protocol (LSP) implementation for TypeScript using tsserver",
   "author": "TypeFox and others",
   "license": "Apache-2.0",
-  "engines": {
-    "node": ">=12"
-  },
-  "eslintIgnore": [
-    "!.eslintrc.js"
-  ],
   "repository": {
     "type": "git",
     "url": "https://github.com/typescript-language-server/typescript-language-server.git"
   },
+  "type": "module",
+  "engines": {
+    "node": ">=14.16"
+  },
   "files": [
     "lib"
   ],
@@ -32,6 +30,9 @@
     "postversion": "git push --follow-tags",
     "prepare": "cd test-data/jsx && yarn"
   },
+  "eslintIgnore": [
+    "!.eslintrc.cjs"
+  ],
   "husky": {
     "hooks": {
       "pre-commit": "yarn lint && yarn build && yarn test:compiled",
@@ -41,10 +42,10 @@
   "dependencies": {
     "commander": "^9.4.0",
     "fs-extra": "^10.1.0",
-    "p-debounce": "^2.1.0",
-    "pkg-up": "^3.1.0",
+    "p-debounce": "^4.0.0",
+    "pkg-up": "^4.0.0",
     "semver": "^7.3.7",
-    "tempy": "^1.0.1",
+    "tempy": "^3.0.0",
     "vscode-languageserver": "^8.0.2",
     "vscode-languageserver-protocol": "^3.17.2",
     "vscode-languageserver-textdocument": "1.0.5",

src/calls.ts

@@ -1,10 +1,10 @@
 
-import tsp from 'typescript/lib/protocol';
-import * as lsp from 'vscode-languageserver/node';
-import * as lspcalls from './lsp-protocol.calls.proposed';
-import { TspClient } from './tsp-client';
-import { CommandTypes } from './tsp-command-types';
-import { uriToPath, toLocation, asRange, Range, toSymbolKind, pathToUri } from './protocol-translation';
+import type tsp from 'typescript/lib/protocol.d.js';
+import * as lsp from 'vscode-languageserver';
+import * as lspcalls from './lsp-protocol.calls.proposed.js';
+import { TspClient } from './tsp-client.js';
+import { CommandTypes } from './tsp-command-types.js';
+import { uriToPath, toLocation, asRange, Range, toSymbolKind, pathToUri } from './protocol-translation.js';
 import { TextDocument } from 'vscode-languageserver-textdocument';
 
 export async function computeCallers(tspClient: TspClient, args: lsp.TextDocumentPositionParams): Promise<lspcalls.CallsResult> {

src/cli.ts

@@ -6,15 +6,16 @@
  * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
  */
 
+import { readFileSync } from 'node:fs';
 import { Command } from 'commander';
-import { createLspConnection } from './lsp-connection';
-import * as lsp from 'vscode-languageserver/node';
+import { createLspConnection } from './lsp-connection.js';
+import * as lsp from 'vscode-languageserver';
 
 const DEFAULT_LOG_LEVEL = lsp.MessageType.Info;
+const { version } = JSON.parse(readFileSync(new URL('../package.json', import.meta.url), { encoding: 'utf8' }));
 
 const program = new Command('typescript-language-server')
-    // eslint-disable-next-line @typescript-eslint/no-require-imports, @typescript-eslint/no-var-requires
-    .version(require('../package.json').version)
+    .version(version)
     .requiredOption('--stdio', 'use stdio')
     .option('--log-level <logLevel>', 'A number indicating the log level (4 = log, 3 = info, 2 = warn, 1 = error). Defaults to `2`.')
     .option('--tsserver-log-file <tsserverLogFile>', 'Specify a tsserver log file. example: --tsserver-log-file ts-logs.txt')

src/completion.ts

@@ -5,16 +5,16 @@
  * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
  */
 
-import * as lsp from 'vscode-languageserver/node';
-import type tsp from 'typescript/lib/protocol';
-import { LspDocument } from './document';
-import { CommandTypes, KindModifiers, ScriptElementKind } from './tsp-command-types';
-import { asRange, toTextEdit, asPlainText, asDocumentation, normalizePath } from './protocol-translation';
-import { Commands } from './commands';
-import { TspClient } from './tsp-client';
-import { CompletionOptions, DisplayPartKind, SupportedFeatures } from './ts-protocol';
-import SnippetString from './utils/SnippetString';
-import * as typeConverters from './utils/typeConverters';
+import * as lsp from 'vscode-languageserver';
+import type tsp from 'typescript/lib/protocol.js';
+import { LspDocument } from './document.js';
+import { CommandTypes, KindModifiers, ScriptElementKind } from './tsp-command-types.js';
+import { asRange, toTextEdit, asPlainText, asDocumentation, normalizePath } from './protocol-translation.js';
+import { Commands } from './commands.js';
+import { TspClient } from './tsp-client.js';
+import { CompletionOptions, DisplayPartKind, SupportedFeatures } from './ts-protocol.js';
+import SnippetString from './utils/SnippetString.js';
+import * as typeConverters from './utils/typeConverters.js';
 
 interface TSCompletionItem extends lsp.CompletionItem {
     data: tsp.CompletionDetailsRequestArgs;

src/diagnostic-queue.ts

@@ -5,13 +5,13 @@
  * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
  */
 
-import tsp from 'typescript/lib/protocol';
-import * as lsp from 'vscode-languageserver/node';
-import { Logger } from './logger';
-import { pathToUri, toDiagnostic } from './protocol-translation';
-import { EventTypes } from './tsp-command-types';
+import type tsp from 'typescript/lib/protocol.d.js';
+import * as lsp from 'vscode-languageserver';
 import debounce from 'p-debounce';
-import { LspDocuments } from './document';
+import { Logger } from './logger.js';
+import { pathToUri, toDiagnostic } from './protocol-translation.js';
+import { EventTypes } from './tsp-command-types.js';
+import { LspDocuments } from './document.js';
 
 class FileDiagnostics {
     private readonly diagnosticsPerKind = new Map<EventTypes, tsp.Diagnostic[]>();

src/document-symbol.ts

@@ -5,10 +5,10 @@
  * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
  */
 
-import * as lsp from 'vscode-languageserver/node';
-import tsp from 'typescript/lib/protocol';
-import { asRange, toSymbolKind, Range } from './protocol-translation';
-import { ScriptElementKind } from './tsp-command-types';
+import * as lsp from 'vscode-languageserver';
+import type tsp from 'typescript/lib/protocol.d.js';
+import { asRange, toSymbolKind, Range } from './protocol-translation.js';
+import { ScriptElementKind } from './tsp-command-types.js';
 
 export function collectDocumentSymbols(parent: tsp.NavigationTree, symbols: lsp.DocumentSymbol[]): boolean {
     return collectDocumentSymbolsInRange(parent, symbols, { start: asRange(parent.spans[0]).start, end: asRange(parent.spans[parent.spans.length - 1]).end });

src/document.ts

@@ -5,7 +5,7 @@
  * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
  */
 
-import * as lsp from 'vscode-languageserver/node';
+import * as lsp from 'vscode-languageserver';
 import { TextDocument } from 'vscode-languageserver-textdocument';
 
 export class LspDocument implements TextDocument {

src/features/fix-all.ts

@@ -3,14 +3,15 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import tsp, { CommandTypes } from 'typescript/lib/protocol';
-import * as lsp from 'vscode-languageserver/node';
-import { LspDocuments } from '../document';
-import { toFileRangeRequestArgs, toTextDocumentEdit } from '../protocol-translation';
-import { TspClient } from '../tsp-client';
-import * as errorCodes from '../utils/errorCodes';
-import * as fixNames from '../utils/fixNames';
-import { CodeActionKind } from '../utils/types';
+import type tsp from 'typescript/lib/protocol.d.js';
+import * as lsp from 'vscode-languageserver';
+import { LspDocuments } from '../document.js';
+import { toFileRangeRequestArgs, toTextDocumentEdit } from '../protocol-translation.js';
+import { TspClient } from '../tsp-client.js';
+import { CommandTypes } from '../tsp-command-types.js';
+import * as errorCodes from '../utils/errorCodes.js';
+import * as fixNames from '../utils/fixNames.js';
+import { CodeActionKind } from '../utils/types.js';
 
 interface AutoFix {
     readonly codes: Set<number>;

src/file-lsp-server.spec.ts

@@ -6,8 +6,8 @@
  */
 
 import chai from 'chai';
-import { LspServer } from './lsp-server';
-import { uri, createServer, lastPosition, filePath, readContents, positionAfter } from './test-utils';
+import { LspServer } from './lsp-server.js';
+import { uri, createServer, lastPosition, filePath, readContents, positionAfter } from './test-utils.js';
 
 const assert = chai.assert;
 

src/hover.ts

@@ -5,9 +5,9 @@
  * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
  */
 
-import * as lsp from 'vscode-languageserver/node';
-import tsp from 'typescript/lib/protocol';
-import { asDocumentation, asPlainText } from './protocol-translation';
+import * as lsp from 'vscode-languageserver';
+import type tsp from 'typescript/lib/protocol.d.js';
+import { asDocumentation, asPlainText } from './protocol-translation.js';
 
 export function asSignatureHelp(info: tsp.SignatureHelpItems): lsp.SignatureHelp {
     return {

src/logger.ts

@@ -5,8 +5,8 @@
  * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
  */
 
-import { LspClient } from './lsp-client';
-import * as lsp from 'vscode-languageserver/node';
+import { LspClient } from './lsp-client.js';
+import * as lsp from 'vscode-languageserver';
 
 /**
  * the logger type

src/lsp-client.ts

@@ -5,8 +5,8 @@
  * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
  */
 
-import * as lsp from 'vscode-languageserver/node';
-import { TypeScriptRenameRequest } from './ts-protocol';
+import * as lsp from 'vscode-languageserver';
+import { TypeScriptRenameRequest } from './ts-protocol.js';
 
 export interface ProgressReporter {
     begin(message?: string): void;

src/lsp-connection.ts

@@ -5,13 +5,12 @@
  * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
  */
 
-import * as lsp from 'vscode-languageserver/node';
-import * as lspcalls from './lsp-protocol.calls.proposed';
-import * as lspinlayHints from './lsp-protocol.inlayHints.proposed';
-
-import { LspClientLogger } from './logger';
-import { LspServer } from './lsp-server';
-import { LspClientImpl } from './lsp-client';
+import * as lsp from 'vscode-languageserver/node.js';
+import * as lspcalls from './lsp-protocol.calls.proposed.js';
+import * as lspinlayHints from './lsp-protocol.inlayHints.proposed.js';
+import { LspClientLogger } from './logger.js';
+import { LspServer } from './lsp-server.js';
+import { LspClientImpl } from './lsp-client.js';
 
 export interface IServerOptions {
     tsserverPath: string;

src/lsp-protocol.calls.proposed.ts

@@ -6,7 +6,7 @@
 
 import { RequestHandler } from 'vscode-jsonrpc';
 import { Location, SymbolKind, Range, DocumentSymbol } from 'vscode-languageserver-types';
-import * as lsp from 'vscode-languageserver/node';
+import * as lsp from 'vscode-languageserver';
 
 export interface CallsClientCapabilities {
     /**

src/lsp-protocol.inlayHints.proposed.ts

@@ -1,5 +1,5 @@
-import * as lsp from 'vscode-languageserver/node';
-import tsp from 'typescript/lib/protocol';
+import * as lsp from 'vscode-languageserver';
+import type tsp from 'typescript/lib/protocol.d.js';
 import { RequestHandler } from 'vscode-jsonrpc';
 
 export type InlayHintsParams = {

src/lsp-server.spec.ts

@@ -6,14 +6,14 @@
  */
 
 import * as chai from 'chai';
-import * as fs from 'fs-extra';
-import * as lsp from 'vscode-languageserver/node';
-import * as lspcalls from './lsp-protocol.calls.proposed';
-import { uri, createServer, position, lastPosition, filePath, getDefaultClientCapabilities, positionAfter, readContents, TestLspServer, toPlatformEOL } from './test-utils';
+import fs from 'fs-extra';
+import * as lsp from 'vscode-languageserver';
+import * as lspcalls from './lsp-protocol.calls.proposed.js';
+import { uri, createServer, position, lastPosition, filePath, getDefaultClientCapabilities, positionAfter, readContents, TestLspServer, toPlatformEOL } from './test-utils.js';
 import { TextDocument } from 'vscode-languageserver-textdocument';
-import { Commands } from './commands';
-import { TypeScriptWorkspaceSettings } from './ts-protocol';
-import { CodeActionKind } from './utils/types';
+import { Commands } from './commands.js';
+import { TypeScriptWorkspaceSettings } from './ts-protocol.js';
+import { CodeActionKind } from './utils/types.js';
 
 const assert = chai.assert;
 
@@ -1426,7 +1426,7 @@ describe('executeCommand', () => {
         const change2 = changes![uri('newFn.ts')];
         assert.isDefined(change2);
         // Clean up file that is created on applying edit.
-        fs.unlink(filePath('newFn.ts'));
+        fs.unlinkSync(filePath('newFn.ts'));
         assert.deepEqual(
             change1,
             [

src/lsp-server.ts

@@ -5,41 +5,40 @@
  * You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
  */
 
-import * as path from 'path';
-import tempy from 'tempy';
-import * as lsp from 'vscode-languageserver/node';
-import * as lspcalls from './lsp-protocol.calls.proposed';
-import * as lspinlayHints from './lsp-protocol.inlayHints.proposed';
-import * as lspsemanticTokens from './semantic-tokens';
-import tsp from 'typescript/lib/protocol';
-import * as fs from 'fs-extra';
+import * as path from 'node:path';
+import fs from 'fs-extra';
 import debounce from 'p-debounce';
-
-import API from './utils/api';
-import { CommandTypes, EventTypes } from './tsp-command-types';
-import { Logger, PrefixingLogger } from './logger';
-import { TspClient } from './tsp-client';
-import { DiagnosticEventQueue } from './diagnostic-queue';
+import { temporaryFile } from 'tempy';
+import * as lsp from 'vscode-languageserver';
+import * as lspcalls from './lsp-protocol.calls.proposed.js';
+import * as lspinlayHints from './lsp-protocol.inlayHints.proposed.js';
+import * as lspsemanticTokens from './semantic-tokens.js';
+import tsp from 'typescript/lib/protocol.d.js';
+import API from './utils/api.js';
+import { CommandTypes, EventTypes } from './tsp-command-types.js';
+import { Logger, PrefixingLogger } from './logger.js';
+import { TspClient } from './tsp-client.js';
+import { DiagnosticEventQueue } from './diagnostic-queue.js';
 import {
     toDocumentHighlight, asRange, asTagsDocumentation,
     uriToPath, toSymbolKind, toLocation, toPosition,
     pathToUri, toTextEdit, toFileRangeRequestArgs, asPlainText, normalizePath
-} from './protocol-translation';
-import { LspDocuments, LspDocument } from './document';
-import { asCompletionItem, asResolvedCompletionItem, getCompletionTriggerCharacter } from './completion';
-import { asSignatureHelp } from './hover';
-import { Commands } from './commands';
-import { provideQuickFix } from './quickfix';
-import { provideRefactors } from './refactor';
-import { provideOrganizeImports } from './organize-imports';
-import { TypeScriptInitializeParams, TypeScriptInitializationOptions, TypeScriptInitializeResult, TypeScriptWorkspaceSettings, TypeScriptWorkspaceSettingsLanguageSettings, SupportedFeatures } from './ts-protocol';
-import { collectDocumentSymbols, collectSymbolInformation } from './document-symbol';
-import { computeCallers, computeCallees } from './calls';
-import { IServerOptions } from './utils/configuration';
-import { TypeScriptVersion, TypeScriptVersionProvider } from './utils/versionProvider';
-import { TypeScriptAutoFixProvider } from './features/fix-all';
-import { LspClient, ProgressReporter } from './lsp-client';
-import { CodeActionKind } from './utils/types';
+} from './protocol-translation.js';
+import { LspDocuments, LspDocument } from './document.js';
+import { asCompletionItem, asResolvedCompletionItem, getCompletionTriggerCharacter } from './completion.js';
+import { asSignatureHelp } from './hover.js';
+import { Commands } from './commands.js';
+import { provideQuickFix } from './quickfix.js';
+import { provideRefactors } from './refactor.js';
+import { provideOrganizeImports } from './organize-imports.js';
+import { TypeScriptInitializeParams, TypeScriptInitializationOptions, TypeScriptInitializeResult, TypeScriptWorkspaceSettings, TypeScriptWorkspaceSettingsLanguageSettings, SupportedFeatures } from './ts-protocol.js';
+import { collectDocumentSymbols, collectSymbolInformation } from './document-symbol.js';
+import { computeCallers, computeCallees } from './calls.js';
+import { IServerOptions } from './utils/configuration.js';
+import { TypeScriptVersion, TypeScriptVersionProvider } from './utils/versionProvider.js';
+import { TypeScriptAutoFixProvider } from './features/fix-all.js';
+import { LspClient, ProgressReporter } from './lsp-client.js';
+import { CodeActionKind } from './utils/types.js';
 
 const DEFAULT_TSSERVER_PREFERENCES: Required<tsp.UserPreferences> = {
     allowIncompleteCompletions: true,
@@ -380,7 +379,7 @@ export class LspServer {
             fs.ensureFileSync(logFile);
             return logFile;
         }
-        return tempy.file(<any>{ name: 'tsserver.log' });
+        return temporaryFile({ name: 'tsserver.log' });
     }
     protected doGetLogFile(): string | undefined {
         if (process.env.TSSERVER_LOG_FILE) {

src/organize-imports.spec.ts

@@ -1,8 +1,8 @@
-import tsp from 'typescript/lib/protocol';
+import type tsp from 'typescript/lib/protocol.d.js';
 import * as chai from 'chai';
-import { provideOrganizeImports } from './organize-imports';
-import { filePath, uri } from './test-utils';
-import { CodeActionKind } from './utils/types';
+import { provideOrganizeImports } from './organize-imports.js';
+import { filePath, uri } from './test-utils.js';
+import { CodeActionKind } from './utils/types.js';
 
 describe('provideOrganizeImports', () => {
     it('converts tsserver response to lsp code actions', () => {