fix: try to fix some places of potential performance degradation, refs #366

Author: s-panferov

src/__test__/exclude.ts

@@ -0,0 +1,33 @@
+import {
+    src, webpackConfig, expectErrors,
+    tsconfig, compile, file, entry, spec
+} from './utils';
+
+spec(__filename, async function() {
+    file('vendor/with-err.ts', `
+        export function error(a: number, b: string): number {
+            return a + b
+        }
+    `);
+
+    file('vendor/with-err21.ts', `
+        export function error(a, b)asdf {
+            return a + b
+        }
+    `);
+
+    src('index.tsx', `
+        console.log(1);
+    `);
+
+    tsconfig({
+        jsx: 'react',
+        allowJs: true
+    }, {
+        exclude: ['vendor']
+    });
+
+    let stats = await compile(webpackConfig(entry('index.tsx')));
+
+    expectErrors(stats, 0);
+});

src/checker/runtime.ts

@@ -282,6 +282,7 @@ function createChecker(receive: (cb: (msg: Req) => void) => void, send: (msg: Re
     function updateFile(fileName: string, text: string) {
         const file = files[fileName];
         if (file) {
+            if (file.text === text) { return; }
             projectVersion++;
             file.version++;
             file.text = text;