fix: ignore case changes for numbers

Author: pi0

README.md

@@ -68,6 +68,7 @@ Converts first character to lower case
 
 - Splits string by the splitters provided (default: `['-', '_', '/', '.]`)
 - Splits when case changes from lower to upper or upper to lower
+- Ignores numbers for case changes
 - Case is preserved in returned value
 - Is an irreversible function since splitters are omitted
 

src/index.ts

@@ -1,4 +1,9 @@
-export function isUppercase (char: string = '') {
+const NUNBER_CHAR_RE = /[0-9]/
+
+export function isUppercase (char: string = ''): boolean | null {
+  if (NUNBER_CHAR_RE.test(char)) {
+    return null
+  }
   return char.toUpperCase() === char
 }
 

test/scule.test.ts

@@ -9,6 +9,7 @@ describe('splitByCase', () => {
     FooBarBaz: ['Foo', 'Bar', 'Baz'],
     'foo_bar-baz/qux': ['foo', 'bar', 'baz', 'qux'],
     'foo--bar-Baz': ['foo', '', 'bar', 'Baz'],
+    'foo123-bar': ['foo123', 'bar'],
     FOOBar: ['FOO', 'Bar'],
     ALink: ['A', 'Link']
   }