feat: Added boolean validator

Author: typeofweb

__tests__/index.test-d.ts

@@ -1,8 +1,18 @@
 import { expectType } from 'tsd';
 
-import { nullable, optional } from '../src/modifiers';
-import type { TypeOf, Schema } from '../src/types';
-import { validate, date, number, oneOf, string, object, array } from '../src/validators';
+import {
+  validate,
+  date,
+  number,
+  oneOf,
+  string,
+  object,
+  array,
+  boolean,
+  nullable,
+  optional,
+} from '../src';
+import type { TypeOf, Schema } from '../src';
 
 // Schema
 declare const str1: TypeOf<Schema<string, {}, never>>;
@@ -55,6 +65,9 @@ expectType<'a' | null>(validate(validator6)(''));
 const validator7 = optional(nullable(oneOf(['a'])));
 expectType<'a' | null | undefined>(validate(validator7)(''));
 
+const validator8 = optional(nullable(boolean()));
+expectType<boolean | null | undefined>(validate(validator8)(false));
+
 // nested
 const nested1 = object({});
 expectType<{}>(validate(nested1)({}));

__tests__/tests.spec.ts

@@ -4,7 +4,7 @@ import Fc from 'fast-check';
 import { complement, identity, is, lt, prop, __ } from 'ramda';
 import tsd from 'tsd';
 
-import { validate, number, string, date, oneOf, object, array } from '../src';
+import { validate, number, string, date, oneOf, object, array, boolean } from '../src';
 
 const throws = <T extends readonly unknown[]>(predicate: (...args: T) => unknown) => (
   ...args: T
@@ -60,6 +60,16 @@ describe('@typeofweb/schema', () => {
       ));
   });
 
+  describe('boolean', () => {
+    it('should validate booleans', () =>
+      Fc.assert(Fc.property(Fc.boolean(), notThrows(validate(boolean())))));
+
+    it('should not allow other values', () =>
+      Fc.assert(
+        Fc.property(Fc.anything().filter(complement(is(Boolean))), throws(validate(boolean()))),
+      ));
+  });
+
   describe('date', () => {
     it('should validate dates', () =>
       Fc.assert(Fc.property(Fc.date(), notThrows(validate(date())))));

src/index.ts

@@ -1,5 +1,5 @@
 export type { VALIDATORS, ValidatorToType } from './validators';
-export { validate, oneOf, string, number, date, array, object } from './validators';
+export { validate, oneOf, string, number, boolean, date, array, object } from './validators';
 
 export type { TypeOf, Schema, AnySchema } from './types';
 export { optional, nullable } from './modifiers';

src/validators.ts

@@ -1,11 +1,13 @@
 const LITERAL_VALIDATOR = Symbol('_literal');
 const STRING_VALIDATOR = Symbol('string');
 const NUMBER_VALIDATOR = Symbol('number');
+const BOOLEAN_VALIDATOR = Symbol('boolean');
 const DATE_VALIDATOR = Symbol('Date');
 export type VALIDATORS =
   | typeof LITERAL_VALIDATOR
   | typeof STRING_VALIDATOR
   | typeof NUMBER_VALIDATOR
+  | typeof BOOLEAN_VALIDATOR
   | typeof DATE_VALIDATOR
   | Record<keyof any, AnySchema>
   | readonly AnySchema[];
@@ -14,6 +16,7 @@ export interface ValidatorToType {
   readonly [STRING_VALIDATOR]: string;
   readonly [NUMBER_VALIDATOR]: number;
   readonly [DATE_VALIDATOR]: Date;
+  readonly [BOOLEAN_VALIDATOR]: boolean;
 }
 
 import { ValidationError } from './errors';
@@ -97,6 +100,11 @@ export const validate = <S extends AnySchema>(schema: S) => (value: unknown): Ty
         throw new ValidationError();
       }
       return value as TypeOf<S>;
+    case BOOLEAN_VALIDATOR:
+      if (typeof value !== 'boolean') {
+        throw new ValidationError();
+      }
+      return value as TypeOf<S>;
     case DATE_VALIDATOR:
       if (Object.prototype.toString.call(value) !== '[object Date]') {
         throw new ValidationError();
@@ -135,6 +143,12 @@ export const number = () => {
   } as Schema<number, { readonly optional: false; readonly nullable: false }, never>;
 };
 
+export const boolean = () => {
+  return {
+    __validator: BOOLEAN_VALIDATOR,
+  } as Schema<boolean, { readonly optional: false; readonly nullable: false }, never>;
+};
+
 export const date = () => {
   return {
     __validator: DATE_VALIDATOR,