Merge pull request microsoft#151830 from microsoft/joh/independent-lungfish

make sure ts-builder instance is being re-used

Author: jrieken

build/lib/tsb/index.js

@@ -51,8 +51,11 @@ function create(projectPath, existingOptions, config, onError = _defaultOnError)
         }
     }
     // FULL COMPILE stream doing transpile, syntax and semantic diagnostics
+    let _builder;
     function createCompileStream(token) {
-        const _builder = builder.createTypeScriptBuilder({ logFn }, projectPath, cmdLine);
+        if (!_builder) {
+            _builder = builder.createTypeScriptBuilder({ logFn }, projectPath, cmdLine);
+        }
         return through(function (file) {
             // give the file to the compiler
             if (file.isStream()) {

build/lib/tsb/index.ts

@@ -73,9 +73,13 @@ export function create(
 	}
 
 	// FULL COMPILE stream doing transpile, syntax and semantic diagnostics
+
+	let _builder!: builder.ITypeScriptBuilder;
 	function createCompileStream(token?: builder.CancellationToken): Readable & Writable {
 
-		const _builder = builder.createTypeScriptBuilder({ logFn }, projectPath, cmdLine);
+		if (!_builder) {
+			_builder = builder.createTypeScriptBuilder({ logFn }, projectPath, cmdLine);
+		}
 
 		return through(function (this: through.ThroughStream, file: Vinyl) {
 			// give the file to the compiler