Make file icons extensions case-insensitive

app/assets/javascripts/vue_shared/components/file_icon/file_icon_map.js

@@ -586,5 +586,16 @@ const fileNameIcons = {
 };
 
 export default function getIconForFile(name) {
-  return fileNameIcons[name] || fileExtensionIcons[name ? name.split('.').pop() : ''] || '';
+  return (
+    fileNameIcons[name] ||
+    fileExtensionIcons[
+      name
+        ? name
+            .split('.')
+            .pop()
+            .toLowerCase()
+        : ''
+    ] ||
+    ''
+  );
 }

changelogs/unreleased/231488-file-icons-case-insensitive-extension.yml

+---
+title: Make file icons extension detection be case-insensitive
+merge_request: 37817
+author:
+type: fixed

spec/frontend/vue_shared/components/file_icon_spec.js

@@ -36,6 +36,9 @@ describe('File Icon component', () => {
     fileName        | iconName
     ${'test.js'}    | ${'javascript'}
     ${'test.png'}   | ${'image'}
+    ${'test.PNG'}   | ${'image'}
+    ${'.npmrc'}     | ${'npm'}
+    ${'.Npmrc'}     | ${'file'}
     ${'webpack.js'} | ${'webpack'}
   `('should render a $iconName icon based on file ending', ({ fileName, iconName }) => {
     createComponent({ fileName });