fix(useFavicon): writable return type (#2036)

Co-authored-by: Anthony Fu <anthonyfu117@hotmail.com>

packages/core/useFavicon/index.ts

@@ -1,5 +1,6 @@
-import type { MaybeComputedRef } from '@vueuse/shared'
+import type { MaybeComputedRef, MaybeReadonlyRef, MaybeRef } from '@vueuse/shared'
 import { isString, resolveRef } from '@vueuse/shared'
+import type { ComputedRef, Ref, WritableComputedRef } from 'vue-demi'
 import { watch } from 'vue-demi'
 import type { ConfigurableDocument } from '../_configurable'
 import { defaultDocument } from '../_configurable'
@@ -16,6 +17,14 @@ export interface UseFaviconOptions extends ConfigurableDocument {
  * @param newIcon
  * @param options
  */
+export function useFavicon(
+  newIcon?: MaybeReadonlyRef<string | null | undefined>,
+  options?: UseFaviconOptions
+): ComputedRef<string | null | undefined>
+export function useFavicon(
+  newIcon: MaybeRef<string | null | undefined>,
+  options?: UseFaviconOptions
+): Ref<string | null | undefined>
 export function useFavicon(
   newIcon: MaybeComputedRef<string | null | undefined> = null,
   options: UseFaviconOptions = {},
@@ -43,7 +52,7 @@ export function useFavicon(
     { immediate: true },
   )
 
-  return favicon
+  return favicon as WritableComputedRef<string | null | undefined>
 }
 
 export type UseFaviconReturn = ReturnType<typeof useFavicon>

packages/shared/utils/types.ts

@@ -31,10 +31,19 @@ export type MaybeRef<T> = T | Ref<T>
  * Maybe it's a ref, or a plain value, or a getter function
  *
  * ```ts
- * type MaybeComputedRef<T> = T | Ref<T> | (() => T)
+ * type MaybeComputedRef<T> = (() => T) | T | Ref<T> | ComputedRef<T>
  * ```
  */
-export type MaybeComputedRef<T> = (() => T) | T | Ref<T> | ComputedRef<T>
+export type MaybeComputedRef<T> = MaybeReadonlyRef<T> | MaybeRef<T>
+
+/**
+ * Maybe it's a computed ref, or a getter function
+ *
+ * ```ts
+ * type MaybeReadonlyRef<T> = (() => T) | ComputedRef<T>
+ * ```
+ */
+export type MaybeReadonlyRef<T> = (() => T) | ComputedRef<T>
 
 /**
  * Make all the nested attributes of an object or array to MaybeRef<T>