feat(core): detect config file indentation and keep it

Ovidiu Barabula · Ovidiu Barabula · commit 86c682e3d038 · 2018-04-01T12:56:04.000+03:00
diff --git a/package.json b/package.json
@@ -54,6 +54,7 @@
   "dependencies": {
     "chalk": "^2.3.2",
     "commander": "^2.15.0",
+    "detect-indent": "^5.0.0",
     "gulp": "^4.0.0",
     "inquirer": "^5.2.0"
   },
@@ -65,6 +66,7 @@
     "@types/chai-as-promised": "^7.1.0",
     "@types/chalk": "^2.2.0",
     "@types/commander": "^2.12.2",
+    "@types/detect-indent": "^5.0.0",
     "@types/gulp": "^4.0.5",
     "@types/inquirer": "^0.0.38",
     "@types/lodash": "^4.14.104",
diff --git a/src/util/file-reader.ts b/src/util/file-reader.ts
@@ -5,6 +5,7 @@
  * @since 0.1.0
  */
 
+import * as detectIndent from 'detect-indent';
 import * as fs from 'fs';
 import { Config } from '../config-manager';
 
@@ -37,6 +38,10 @@ function FileReader(filepath: string): FileReader {
     throw new Error(ERRORS.PATH_NOT_STRING);
   }
 
+  // File indentation will be assigned at first read
+  let fileIndent: string;
+  const defaultIndent: string = '  ';
+
 
   /**
    * Get file contents
@@ -49,6 +54,10 @@ function FileReader(filepath: string): FileReader {
           return reject(new Error(`${ERRORS.READ_ERROR}: ${readError.message}`));
         }
 
+        if (typeof fileIndent === 'undefined') {
+          fileIndent = detectIndent(data).indent || defaultIndent;
+        }
+
         let parsedJson;
         try {
           parsedJson = JSON.parse(data);
@@ -68,8 +77,7 @@ function FileReader(filepath: string): FileReader {
    */
   function write(object: Config): Promise<boolean|Error> {
     return new Promise((resolve, reject) => {
-      // TODO: replace 2 with 'detect-indent' module's output
-      const content = JSON.stringify(object, null, 2);
+      const content = JSON.stringify(object, null, fileIndent);
       // Write the file content with an empty line at the end
       fs.writeFile(filepath, `${content}\n`, writeError => {
         if (writeError) {
diff --git a/webpack.config.babel.js b/webpack.config.babel.js
@@ -70,6 +70,7 @@ const configuration = {
     commander: 'commander',
     gulp: 'gulp',
     inquirer: 'inquirer',
+    'detect-indent': 'detect-indent',
   },
 
   optimization: {
diff --git a/yarn.lock b/yarn.lock
@@ -613,6 +613,10 @@
   dependencies:
     commander "*"
 
+"@types/detect-indent@^5.0.0":
+  version "5.0.0"
+  resolved "https://registry.yarnpkg.com/@types/detect-indent/-/detect-indent-5.0.0.tgz#8b1bbd7891268d5ed20d23ecd23ae333d33934cd"
+
 "@types/events@*":
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/@types/events/-/events-1.2.0.tgz#81a6731ce4df43619e5c8c945383b3e62a89ea86"
@@ -2929,6 +2933,10 @@ detect-indent@4.0.0, detect-indent@^4.0.0:
   dependencies:
     repeating "^2.0.0"
 
+detect-indent@^5.0.0:
+  version "5.0.0"
+  resolved "https://registry.yarnpkg.com/detect-indent/-/detect-indent-5.0.0.tgz#3871cc0a6a002e8c3e5b3cf7f336264675f06b9d"
+
 detect-libc@^1.0.2:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/detect-libc/-/detect-libc-1.0.3.tgz#fa137c4bd698edf55cd5cd02ac559f91a4c4ba9b"
