Avoid extension overwrite app.json in expo application (#1849)

* Add log

* Update

* Update

src/common/utils.ts

@@ -1,10 +1,11 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for details.
 import * as path from "path";
-import json5 = require("json5");
 import { ChildProcess } from "./node/childProcess";
 import { HostPlatform } from "./hostPlatform";
 import customRequire from "./customRequire";
+import stripJsonComments = require("strip-json-comments");
+import { parse } from "json5";
 
 export function removeModuleFromRequireCacheByName(moduleName: string): void {
     const moduleKey = Object.keys(customRequire.cache).find(key => key.includes(moduleName));
@@ -69,6 +70,11 @@ function padZeroes(minDesiredLength: number, numberToPad: string): string {
 export function stripJsonTrailingComma(str: string): any {
     const endOfStringTrailingCommaRegex = /,\s*$/g;
     const result = str.replace(endOfStringTrailingCommaRegex, "");
-    const objResult = json5.parse(result);
+    let objResult;
+    try {
+        objResult = parse(result);
+    } catch {
+        objResult = JSON.parse(stripJsonComments(str));
+    }
     return objResult;
 }

src/extension/exponent/exponentHelper.ts

@@ -9,6 +9,7 @@ import * as semver from "semver";
 import * as vscode from "vscode";
 import { sync as globSync } from "glob";
 import * as nls from "vscode-nls";
+import { logger } from "vscode-debugadapter";
 import { stripJsonTrailingComma, getNodeModulesGlobalPath } from "../../common/utils";
 import { Package, IPackageInformation } from "../../common/node/package";
 import { ProjectVersionHelper } from "../../common/projectVersionHelper";
@@ -309,9 +310,11 @@ require('${entryPoint}');`;
     private async patchAppJson(isExpo: boolean = true): Promise<void> {
         let appJson: AppJson;
         try {
+            logger.log("Reading app.json file.");
             appJson = await this.readAppJson();
         } catch {
-            // if app.json doesn't exist but it's ok, we will create it
+            // If app.json doesn't exist, we will create it
+            logger.log("Cannot get existing app.json file. Create new one.");
             appJson = <AppJson>{};
         }
         const packageName = await this.getPackageName();
@@ -442,6 +445,7 @@ require('${entryPoint}');`;
 
     private async readAppJson(): Promise<AppJson> {
         const appJsonPath = this.pathToFileInWorkspace(APP_JSON);
+        logger.log(`Getting app.json path: ${appJsonPath}`);
         return this.fs.readFile(appJsonPath).then(content => {
             return stripJsonTrailingComma(content.toString());
         });