Add ability to customize command-line arguments passed to Ruby

README.md

@@ -21,6 +21,10 @@ Your Config in Atom menu):
   # ruby path. run `which ruby` to find the path.
   'rubyExecutablePath': null
 
+  # arguments passed to ruby.
+  # add -Ku if you experience problems with utf-8 encoding on macOS.
+  'rubyExecutableArgs': '-c -w --external-encoding=utf-8 --internal-encoding=utf-8 -Ku'
+
   # ignored extensions, ERB and markdown files by default.
   'ignoredExtensions': 'erb, md'
 ```

lib/main.js

@@ -14,6 +14,9 @@ export default {
       atom.config.observe('linter-ruby.rubyExecutablePath', (value) => {
         this.executablePath = value;
       }),
+      atom.config.observe('linter-ruby.rubyExecutableArgs', (value) => {
+        this.executableArgs = value;
+      }),
       atom.config.observe('linter-ruby.ignoredExtensions', (value) => {
         this.ignoredExtensions = value;
       }),
@@ -44,13 +47,7 @@ export default {
           return [];
         }
 
-        const execArgs = [
-          '-c', // Check syntax only, no execution
-          '-w', // Turns on warnings
-          // Set the encoding to UTF-8
-          '--external-encoding=utf-8',
-          '--internal-encoding=utf-8',
-        ];
+        const execArgs = this.executableArgs.split(/\s+/);
         const execOpts = {
           stdin: fileText,
           stream: 'stderr',

package.json

@@ -17,6 +17,11 @@
       "type": "string",
       "default": "ruby"
     },
+    "rubyExecutableArgs": {
+      "title": "Arguments passed to Ruby",
+      "type": "string",
+      "default": "-c -w --external-encoding=utf-8 --internal-encoding=utf-8"
+    },
     "ignoredExtensions": {
       "type": "array",
       "default": [