feat(prototype): add validator for prototype

combinator.ts

@@ -12,6 +12,7 @@ import { FixedArrayValidator } from "./validators/array/fixed_array.ts";
 import { DictionaryValidator } from "./validators/object/dictionary.ts";
 import { OptionalValidator } from "./validators/object/optional.ts";
 import { NullishValidator } from "./validators/nullish.ts";
+import { PrototypeValidator } from "./validators/prototype.ts";
 import { IntegerValidator } from "./validators/number/integer.ts";
 import { PositiveNumberValidator } from "./validators/number/positive_number.ts";
 import { NegativeNumberValidator } from "./validators/number/negative_number.ts";
@@ -64,7 +65,9 @@ export const enumerate = /* @__PURE__ */ ctorFn(
 export const instance = /* @__PURE__ */ ctorFn(
   /* @__PURE__ */ bind(InstanceValidator).expect(message1).build(),
 );
-
+export const prototype = /* @__PURE__ */ ctorFn(
+  /* @__PURE__ */ bind(PrototypeValidator).expect(shouldBeBut).build(),
+);
 export const object = /* @__PURE__ */ ctorFn(DictionaryValidator);
 export const optional = /* @__PURE__ */ ctorFn(OptionalValidator);
 export const nullish = /* @__PURE__ */ new NullishValidator();

mod.ts

@@ -50,6 +50,7 @@ export {
   or,
   pattern,
   positive,
+  prototype,
   single,
   string,
   symbol,

validators/prototype.ts

@@ -0,0 +1,21 @@
+// deno-lint-ignore-file ban-types
+// Copyright 2023-latest Tomoki Miyauchi. All rights reserved. MIT license.
+// This module is browser compatible.
+
+import { ScalarValidator } from "../utils.ts";
+
+export class PrototypeValidator extends ScalarValidator<{}> {
+  constructor(public proto: {}) {
+    super();
+  }
+
+  is(input: {}): input is {} {
+    const is = Object.getPrototypeOf(input) === this.proto;
+
+    return is;
+  }
+
+  override toString(): string {
+    return `prototype of ${Object.getPrototypeOf(this.proto)}`;
+  }
+}