Fix unnamed placeholders extraction (#25)

* Fix unnamed placeholders extraction

* Rearrange test examples into positional group

---------

Co-authored-by: Andrew Duthie <andrew@andrewduthie.com>

Author: sdnunca

packages/sprintf/__tests__/sprintf.test.ts

@@ -36,6 +36,8 @@ sprintf('%1$f, %2$f', [1.2, 1.4]);
 sprintf('%2$f, %1$f', 1.2, 1.4);
 sprintf('%2$f, %1$f', [1.2, 1.4]);
 sprintf('Hello %2$d, Number %1$d, Float %3$f', 1, 1, 1.2);
+sprintf('Test %s with $ after', 'placeholder');
+sprintf('Test $ before %s', 'placeholder');
 
 // / InCorrect
 // @ts-expect-error - argument mismatch, string expected

packages/sprintf/types/index.d.ts

@@ -156,7 +156,7 @@ type ExtractPositionalPlaceholders<T extends string> =
 // Extracts unnamed placeholders like %s, %.2f, %.*d (ignores positional/named)
 type ExtractUnnamedPlaceholders<T extends string> =
 	StripEscapedPercents<T> extends `${infer _}%${infer AfterPercent}`
-		? AfterPercent extends `${infer _Num}$${infer AfterPositional}`
+		? AfterPercent extends `${infer _Num extends `${number}`}$${infer AfterPositional}`
 			? ExtractUnnamedPlaceholders<AfterPositional> // Skip positional
 			: ParsePrecisionAndSpec<AfterPercent> extends [
 						infer Precision extends string,