chore: add overloads for classes method

Author: cexbrayat

src/dom-wrapper.ts

@@ -10,7 +10,9 @@ export class DOMWrapper<ElementType extends Element> {
     this.element = element
   }
 
-  classes(className?: string) {
+  classes(): string[]
+  classes(className: string): boolean
+  classes(className?: string): string[] | boolean {
     const classes = this.element.classList
 
     if (className) return classes.contains(className)

src/vue-wrapper.ts

@@ -50,7 +50,9 @@ export class VueWrapper<T extends ComponentPublicInstance> {
     return selector ? props[selector] : props
   }
 
-  classes(className?: string) {
+  classes(): string[]
+  classes(className: string): boolean
+  classes(className?: string): string[] | boolean {
     return new DOMWrapper(this.element).classes(className)
   }
 

test-dts/wrapper.d-test.ts

@@ -92,3 +92,9 @@ expectType<{ [key: string]: string }>(wrapper.attributes())
 expectType<string>(wrapper.attributes('key'))
 expectType<{ [key: string]: string }>(domWrapper.attributes())
 expectType<string>(domWrapper.attributes('key'))
+
+// classes
+expectType<Array<string>>(wrapper.classes())
+expectType<boolean>(wrapper.classes('class'))
+expectType<Array<string>>(domWrapper.classes())
+expectType<boolean>(domWrapper.classes('class'))