Enable preferConst in TS project

.eslintignore

@@ -14,3 +14,4 @@
 **/extensions/**/build/**
 **/extensions/markdown-language-features/media/**
 **/extensions/typescript-basics/test/colorize-fixtures/**
+**/extensions/typescript-language-features/dist/**

extensions/typescript-language-features/.eslintrc.json

@@ -0,0 +1,5 @@
+{
+ "rules": {
+ "prefer-const": "error"
+ }
+}

extensions/typescript-language-features/src/languageFeatures/completions.ts

@@ -533,7 +533,7 @@ class TypeScriptCompletionItemProvider implements vscode.CompletionItemProvider<
 
  let includesPackageJsonImport = false;
  const items: MyCompletionItem[] = [];
- for (let entry of entries) {
+ for (const entry of entries) {
  if (!shouldExcludeCompletionEntry(entry, completionConfiguration)) {
  items.push(new MyCompletionItem(position, document, entry, completionContext, metadata));
  includesPackageJsonImport = !!entry.isPackageJsonImport;

extensions/typescript-language-features/src/languageFeatures/semanticTokens.ts

@@ -73,7 +73,7 @@ class DocumentSemanticTokensProvider implements vscode.DocumentSemanticTokensPro
  return null;
  }
 
- let versionBeforeRequest = document.version;
+ const versionBeforeRequest = document.version;
 
  const response = await (this.client as ExperimentalProtocol.IExtendedTypeScriptServiceClient).execute('encodedSemanticClassifications-full', requestArg, token, {
  cancelOnResourceChange: document.uri
@@ -137,7 +137,7 @@ class DocumentSemanticTokensProvider implements vscode.DocumentSemanticTokensPro
 function waitForDocumentChangesToEnd(document: vscode.TextDocument) {
  let version = document.version;
  return new Promise<void>((s) => {
- let iv = setInterval(_ => {
+ const iv = setInterval(_ => {
  if (document.version === version) {
  clearInterval(iv);
  s();

extensions/typescript-language-features/src/tsServer/serverProcess.electron.ts

@@ -39,7 +39,7 @@ class ProtocolBuffer {
  if (this.buffer.length - this.index >= toAppend.length) {
  toAppend.copy(this.buffer, this.index, 0, toAppend.length);
  } else {
- let newSize = (Math.ceil((this.index + toAppend.length) / defaultSize) + 1) * defaultSize;
+ const newSize = (Math.ceil((this.index + toAppend.length) / defaultSize) + 1) * defaultSize;
  if (this.index === 0) {
  this.buffer = Buffer.allocUnsafe(newSize);
  toAppend.copy(this.buffer, 0, 0, toAppend.length);
@@ -61,14 +61,14 @@ class ProtocolBuffer {
  return result;
  }
  current += contentLengthSize;
- let start = current;
+ const start = current;
  while (current < this.index && this.buffer[current] !== backslashR) {
  current++;
  }
  if (current + 3 >= this.index || this.buffer[current + 1] !== backslashN || this.buffer[current + 2] !== backslashR || this.buffer[current + 3] !== backslashN) {
  return result;
  }
- let data = this.buffer.toString('utf8', start, current);
+ const data = this.buffer.toString('utf8', start, current);
  result = parseInt(data);
  this.buffer = this.buffer.slice(current + 4);
  this.index = this.index - (current + 4);
@@ -79,7 +79,7 @@ class ProtocolBuffer {
  if (this.index < length) {
  return null;
  }
- let result = this.buffer.toString('utf8', 0, length);
+ const result = this.buffer.toString('utf8', 0, length);
  let sourceStart = length;
  while (sourceStart < this.index && (this.buffer[sourceStart] === backslashR || this.buffer[sourceStart] === backslashN)) {
  sourceStart++;

extensions/typescript-language-features/src/typescriptServiceClient.ts

@@ -374,7 +374,7 @@ export default class TypeScriptServiceClient extends Disposable implements IType
  this.info(`Using tsserver from: ${version.path}`);
 
  const apiVersion = version.apiVersion || API.defaultVersion;
- let mytoken = ++this.token;
+ const mytoken = ++this.token;
  const handle = this.typescriptServerSpawner.spawn(version, this.capabilities, this.configuration, this.pluginManager, this.cancellerFactory, {
  onFatalError: (command, err) => this.fatalError(command, err),
  });