🆕 Determine word regexp based on position

package.json

@@ -54,7 +54,10 @@
         "never"
       ],
       "prefer-arrow-callback": 0,
-      "max-len": [2, 200]
+      "max-len": [
+        2,
+        200
+      ]
     },
     "extends": "airbnb/base",
     "parser": "babel-eslint",

src/helpers.js

@@ -5,7 +5,7 @@
 import FS from 'fs'
 import Temp from 'tmp'
 import promisify from 'sb-promisify'
-import type { TextEditor } from 'atom'
+import type { TextEditor, Range } from 'atom'
 import type { TempDirectory } from './types'
 
 export const writeFile = promisify(FS.writeFile)
@@ -19,6 +19,19 @@ export const assign = Object.assign || function (target, source) {
   return target
 }
 
+function escapeRegexp(string: string): string {
+  // Shamelessly stolen from https://github.com/atom/underscore-plus/blob/130913c179fe1d718a14034f4818adaf8da4db12/src/underscore-plus.coffee#L138
+  return string.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\$&')
+}
+
+export function getWordRegexp(textEditor: TextEditor, bufferPosition: Range) {
+  const scopeDescriptor = textEditor.scopeDescriptorForBufferPosition(bufferPosition)
+  const nonWordCharacters = escapeRegexp(atom.config.get('editor.nonWordCharacters', {
+    scope: scopeDescriptor
+  }))
+  return new RegExp(`^[\t ]*$|[^\\s${nonWordCharacters}]+`)
+}
+
 export function getTempDirectory(prefix: string): Promise<TempDirectory> {
   return new Promise(function (resolve, reject) {
     Temp.dir({ prefix }, function (error, directory, cleanup) {

src/index.js

@@ -45,7 +45,7 @@ export function rangeFromLineNumber(textEditor: TextEditor, line: number, column
 
   let colEnd = lineLength
   const rowText = buffer.lineForRow(lineNumber).substr(colStart)
-  const match = /^( +|[\$\w]+)/.exec(rowText)
+  const match = Helpers.getWordRegexp(textEditor, [lineNumber, colStart]).exec(rowText)
   if (match) {
     colEnd = colStart + match.index + match[0].length
   }