Clean up inferred project config logic

extensions/typescript/src/typescriptServiceClient.ts

@@ -27,6 +27,7 @@ import { TypeScriptServiceConfiguration, TsServerLogLevel } from './utils/config
 import { TypeScriptVersionProvider, TypeScriptVersion } from './utils/versionProvider';
 import { TypeScriptVersionPicker } from './utils/versionPicker';
 import * as fileSchemes from './utils/fileSchemes';
+import { inferredProjectConfig } from './utils/tsconfig';
 
 const localize = nls.loadMessageBundle();
 
@@ -476,20 +477,12 @@ export default class TypeScriptServiceClient implements ITypeScriptServiceClient
 	}
 
 	private getCompilerOptionsForInferredProjects(configuration: TypeScriptServiceConfiguration): Proto.ExternalProjectCompilerOptions {
-		const compilerOptions: Proto.ExternalProjectCompilerOptions = {
-			module: 'CommonJS' as Proto.ModuleKind,
-			target: 'Es2016' as Proto.ScriptTarget,
+		return {
+			...inferredProjectConfig(configuration),
+			allowJs: true,
 			allowSyntheticDefaultImports: true,
 			allowNonTsExtensions: true,
-			allowJs: true,
-			jsx: 'Preserve' as Proto.JsxEmit
 		};
-
-		if (this.apiVersion.has230Features()) {
-			compilerOptions.checkJs = configuration.checkJs;
-			compilerOptions.experimentalDecorators = configuration.experimentalDecorators;
-		}
-		return compilerOptions;
 	}
 
 	private serviceExited(restart: boolean): void {

extensions/typescript/src/utils/tsconfig.ts

@@ -5,27 +5,39 @@
 
 import * as vscode from 'vscode';
 import * as path from 'path';
+import * as Proto from '../protocol';
+
 import { TypeScriptServiceConfiguration } from './configuration';
 
 export function isImplicitProjectConfigFile(configFileName: string) {
 	return configFileName.indexOf('/dev/null/') === 0;
 }
 
-function getEmptyConfig(
-	isTypeScriptProject: boolean,
+export function inferredProjectConfig(
 	config: TypeScriptServiceConfiguration
-) {
-	const compilerOptions = [
-		'"target": "es2016"',
-		'"module": "commonjs"',
-		'"jsx": "preserve"',
-	];
-	if (!isTypeScriptProject && config.checkJs) {
-		compilerOptions.push('"checkJs": true');
+): Proto.ExternalProjectCompilerOptions {
+	const base: Proto.ExternalProjectCompilerOptions = {
+		module: 'commonjs' as Proto.ModuleKind,
+		target: 'es2016' as Proto.ScriptTarget,
+		jsx: 'preserve' as Proto.JsxEmit
+	};
+
+	if (config.checkJs) {
+		base.checkJs = true;
 	}
-	if (!isTypeScriptProject && config.experimentalDecorators) {
-		compilerOptions.push('"experimentalDecorators": true');
+
+	if (config.experimentalDecorators) {
+		base.experimentalDecorators = true;
 	}
+
+	return base;
+}
+
+function getEmptyConfigSnippet(
+	config: TypeScriptServiceConfiguration
+) {
+	const baseConfig = inferredProjectConfig(config);
+	const compilerOptions = Object.keys(baseConfig).map(key => `"${key}": ${JSON.stringify(baseConfig[key])}`);
 	return new vscode.SnippetString(`{
 	"compilerOptions": {
 		${compilerOptions.join(',\n\t\t')}$0
@@ -51,7 +63,7 @@ export async function openOrCreateConfigFile(
 		const doc = await vscode.workspace.openTextDocument(configFile.with({ scheme: 'untitled' }));
 		const editor = await vscode.window.showTextDocument(doc, col);
 		if (editor.document.getText().length === 0) {
-			await editor.insertSnippet(getEmptyConfig(isTypeScriptProject, config));
+			await editor.insertSnippet(getEmptyConfigSnippet(config));
 		}
 		return editor;
 	}