Address PR comments.

src/languages.ts

@@ -11,6 +11,17 @@ interface ExtensionsTypes {
 
 export interface DetectorOptions {}
 
+/**
+ * The extension map can contain multiple languages with the same extension,
+ * but we only want a single one. For the moment, these clashes are resolved
+ * by the simple heuristic below listing high-priority languages. We may want
+ * to consider smarter heuristics to correctly identify languages in cases
+ * where the extension is ambiguous. The ordering of the list matters and
+ * languages earlier on will get a higher priority when resolving clashes.
+ */
+const importantLanguages = ["javascript", "typescript", "ruby", "python", "java", "c", "c++", "c#", "rust", "scala", "perl", "go"];
+
+
 /**
  * detecte program language through file extension
  *
@@ -35,30 +46,22 @@ export class Languages {
   private loadExtensionMap = () => {
     const extensions: ExtensionsTypes = {};
 
-    /**
-     * The extension map can contain multiple languages with the same extension,
-     * but we only want a single one. For the moment, these clashes are resolved
-     * by the simple heuristic below listing high-priority languages. We may want
-     * to consider smarter heuristics to correctly identify languages in cases
-     * where the extension is ambiguous. The ordering of the list matters and
-     * languages earlier on will get a higher priority when resolving clashes.
-     */
-    const importantLanguages = ["javascript", "typescript", "ruby", "python", "java", "c", "c++", "c#", "rust", "scala", "perl", "go"];
-
     Object.keys(languageMap).forEach((language) => {
       const languageMode = languageMap[language];
       const languageExtensions = (languageMode && languageMode.extensions) || [];
       languageExtensions.forEach((extension: string) => {
-        if (!extensions[extension.toLowerCase()]) {
-          extensions[extension.toLowerCase()] = language.toLowerCase();
+        const lowerCaseExtension = extension.toLowerCase();
+        const lowerCaseLanguage = language.toLowerCase()
+        if (!extensions[lowerCaseExtension]) {
+          extensions[lowerCaseExtension] = lowerCaseLanguage;
         } else {
-          const currentLanguagePriority = importantLanguages.indexOf(extensions[extension.toLowerCase()]);
-          if (currentLanguagePriority == -1) {
-            extensions[extension.toLowerCase()] = language.toLowerCase();
+          const currentLanguagePriority = importantLanguages.indexOf(extensions[lowerCaseExtension]);
+          if (currentLanguagePriority === -1) {
+            extensions[lowerCaseExtension] = lowerCaseLanguage;
           } else {
-            const otherPriority = importantLanguages.indexOf(language.toLowerCase());
-            if (otherPriority != -1 && otherPriority < currentLanguagePriority)
-              extensions[extension.toLowerCase()] = language.toLowerCase();
+            const otherPriority = importantLanguages.indexOf(lowerCaseLanguage);
+            if (otherPriority !== -1 && otherPriority < currentLanguagePriority)
+              extensions[lowerCaseExtension] = lowerCaseLanguage;
           }
         }
       });