Fix packageDir array support

CHANGELOG.md

@@ -4,6 +4,9 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 This change log adheres to standards from [Keep a CHANGELOG](http://keepachangelog.com).
 
 ## [Unreleased]
+### Fixed
+- [`no-extraneous-dependencies`]: `packageDir` option with array value was clobbering package deps instead of merging them ([#1175] thanks [@aravindet])
+
 
 ## [2.14.0] - 2018-08-13
 *   69e0187 (HEAD -> master, source/master, origin/master, origin/HEAD) Merge pull request #1151 from jf248/jsx

src/rules/no-extraneous-dependencies.js

@@ -42,9 +42,12 @@ function getDependencies(context, packageDir) {
     if (!isEmpty(paths)) {
       // use rule config to find package.json
       paths.forEach(dir => {
-        Object.assign(packageContent, extractDepFields(
+        const _packageContent = extractDepFields(
           JSON.parse(fs.readFileSync(path.join(dir, 'package.json'), 'utf8'))
-        ))
+        )
+        Object.keys(packageContent).forEach(depsKey =>
+          Object.assign(packageContent[depsKey], _packageContent[depsKey])
+        )
       })
     } else {
       // use closest package.json

tests/files/monorepo/package.json

@@ -1,5 +1,8 @@
 {
   "private": true,
+  "dependencies": {
+    "right-pad": "^1.0.1"
+  },
   "devDependencies": {
     "left-pad": "^1.2.0"
   }

tests/src/rules/no-extraneous-dependencies.js

@@ -90,6 +90,22 @@ ruleTester.run('no-extraneous-dependencies', rule, {
       code: 'import leftpad from "left-pad";',
       options: [{packageDir: packageDirMonoRepoRoot}],
     }),
+    test({
+      code: 'import react from "react";',
+      options: [{packageDir: [packageDirMonoRepoRoot, packageDirMonoRepoWithNested]}],
+    }),
+    test({
+      code: 'import leftpad from "left-pad";',
+      options: [{packageDir: [packageDirMonoRepoRoot, packageDirMonoRepoWithNested]}],
+    }),
+    test({
+      code: 'import leftpad from "left-pad";',
+      options: [{packageDir: [packageDirMonoRepoWithNested, packageDirMonoRepoRoot]}],
+    }),
+    test({
+      code: 'import rightpad from "right-pad";',
+      options: [{packageDir: [packageDirMonoRepoRoot, packageDirMonoRepoWithNested]}],
+    }),
   ],
   invalid: [
     test({