refactor(isPlainObject): use type predicate

refactor: the only use of isPlainObject to not explicitly set the type when it is inferred by predicate

Author: VividLemon

packages/bootstrap-vue-3/src/utils/inspect.ts

@@ -16,5 +16,5 @@ export const isNumeric = (value: unknown): boolean => /^[0-9]*\.?[0-9]+$/.test(S
  * @param obj
  * @returns
  */
-export const isPlainObject = (obj: unknown): boolean =>
+export const isPlainObject = (obj: unknown): obj is Record<PropertyKey, unknown> =>
   Object.prototype.toString.call(obj) === '[object Object]'

packages/bootstrap-vue-3/src/utils/stringUtils.ts

@@ -18,9 +18,7 @@ export const toString = (val: unknown, spaces = 2): string =>
     ? val
     : val === undefined || val === null
     ? ''
-    : Array.isArray(val) ||
-      (isPlainObject(val) &&
-        (val as Record<string, unknown>).toString === Object.prototype.toString)
+    : Array.isArray(val) || (isPlainObject(val) && val.toString === Object.prototype.toString)
     ? JSON.stringify(val, null, spaces)
     : String(val)