From 754ee6fc90f41b7520905c2a4ae30278f6e6b579 Mon Sep 17 00:00:00 2001
From: Charles Lyding <charles@thunderpos.com>
Date: Sat, 4 Mar 2017 01:29:04 -0500
Subject: [PATCH] fix(@ngtools/webpack): allow comments in tsconfig files

---
 packages/@ngtools/webpack/src/plugin.ts         | 13 ++++++++-----
 tests/e2e/assets/webpack/test-app/tsconfig.json |  1 +
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/packages/@ngtools/webpack/src/plugin.ts b/packages/@ngtools/webpack/src/plugin.ts
index bff8a01e15ef..5f510ccd5c50 100644
--- a/packages/@ngtools/webpack/src/plugin.ts
+++ b/packages/@ngtools/webpack/src/plugin.ts
@@ -108,13 +108,16 @@ export class AotPlugin implements Tapable {
       basePath = path.resolve(process.cwd(), options.basePath);
     }
 
-    let tsConfigJson: any = null;
-    try {
-      tsConfigJson = JSON.parse(ts.sys.readFile(this._tsConfigPath));
-    } catch (err) {
-      throw new Error(`An error happened while parsing ${this._tsConfigPath} JSON: ${err}.`);
+    const configResult = ts.readConfigFile(this._tsConfigPath, ts.sys.readFile);
+    if (configResult.error) {
+      const diagnostic = configResult.error;
+      const {line, character} = diagnostic.file.getLineAndCharacterOfPosition(diagnostic.start);
+      const message = ts.flattenDiagnosticMessageText(diagnostic.messageText, '\n');
+      throw new Error(`${diagnostic.file.fileName} (${line + 1},${character + 1}): ${message})`);
     }
 
+    const tsConfigJson = configResult.config;
+
     if (options.hasOwnProperty('compilerOptions')) {
       tsConfigJson.compilerOptions = Object.assign({},
         tsConfigJson.compilerOptions,
diff --git a/tests/e2e/assets/webpack/test-app/tsconfig.json b/tests/e2e/assets/webpack/test-app/tsconfig.json
index cee38681d901..f9ca9f3932a5 100644
--- a/tests/e2e/assets/webpack/test-app/tsconfig.json
+++ b/tests/e2e/assets/webpack/test-app/tsconfig.json
@@ -1,4 +1,5 @@
 {
+  // Test comment
   "compilerOptions": {
     "baseUrl": "",
     "module": "es2015",