Add nullOrBoolean assert

README.md

@@ -46,6 +46,7 @@ The following set of extra asserts are provided by this package:
 - [Json](#json)
 - [NotEmpty](#notempty)
 - [NullOrDate](#nullordate)
+- [NullOrBoolean](#nullorboolean)
 - [NullOrString](#nullorstring)
 - [Phone](#phone) (requires `google-libphonenumber`)
 - [PlainObject](#plainobject)
@@ -191,6 +192,9 @@ Tests if the value is valid json.
 ### NotEmpty
 Tests if the value is not an empty (empty object, empty array, empty string, etc).
 
+### NullOrBoolean
+Tests if the value is a `null` or `boolean`.
+
 ### NullOrString
 Tests if the value is a `null` or `string`, optionally within some boundaries.
 

src/asserts/null-or-boolean-assert.js

@@ -0,0 +1,33 @@
+'use strict';
+
+/**
+ * Module dependencies.
+ */
+
+const { Violation } = require('validator.js');
+
+/**
+ * Export `NullOrBooleanAssert`.
+ */
+
+module.exports = function nullOrBooleanAssert() {
+  /**
+   * Class name.
+   */
+
+  this.__class__ = 'NullOrBoolean';
+
+  /**
+   * Validation algorithm.
+   */
+
+  this.validate = value => {
+    if (value !== null && typeof value !== 'boolean') {
+      throw new Violation(this, value, { value: 'must_be_null_or_a_boolean' });
+    }
+
+    return true;
+  };
+
+  return this;
+};

src/index.js

@@ -29,6 +29,7 @@ const Ip = require('./asserts/ip-assert.js');
 const Iso3166Country = require('./asserts/iso-3166-country-assert.js');
 const Json = require('./asserts/json-assert.js');
 const NotEmpty = require('./asserts/not-empty-assert.js');
+const NullOrBoolean = require('./asserts/null-or-boolean-assert.js');
 const NullOrDate = require('./asserts/null-or-date-assert.js');
 const NullOrString = require('./asserts/null-or-string-assert.js');
 const Phone = require('./asserts/phone-assert.js');
@@ -70,6 +71,7 @@ module.exports = {
   Iso3166Country,
   Json,
   NotEmpty,
+  NullOrBoolean,
   NullOrDate,
   NullOrString,
   Phone,

test/asserts/null-or-boolean-assert.test.js

@@ -0,0 +1,59 @@
+'use strict';
+
+/**
+ * Module dependencies.
+ */
+
+const { Assert: BaseAssert, Violation } = require('validator.js');
+const NullOrBooleanAssert = require('../../src/asserts/null-or-boolean-assert');
+
+/**
+ * Extend `Assert` with `NullOrBooleanAssert`.
+ */
+
+const Assert = BaseAssert.extend({
+  NullOrBoolean: NullOrBooleanAssert
+});
+
+/**
+ * Test `NullOrBooleanAssert`.
+ */
+
+describe('NullOrBooleanAssert', () => {
+  it('should throw an error if the input value is not a `null` or a boolean', () => {
+    const choices = [[], {}, 123, new Boolean(true), 'foo']; // eslint-disable-line no-new-wrappers
+
+    choices.forEach(choice => {
+      try {
+        Assert.nullOrBoolean().validate(choice);
+
+        fail();
+      } catch (e) {
+        expect(e).toBeInstanceOf(Violation);
+        expect(e.violation.value).toBe('must_be_null_or_a_boolean');
+      }
+    });
+  });
+
+  it('should expose `assert` equal to `NullOrBoolean`', () => {
+    try {
+      Assert.nullOrBoolean().validate({});
+
+      fail();
+    } catch (e) {
+      expect(e.show().assert).toBe('NullOrBoolean');
+    }
+  });
+
+  it('should accept `null`', () => {
+    Assert.nullOrBoolean().validate(null);
+  });
+
+  it('should accept a `true` boolean value', () => {
+    Assert.nullOrBoolean().validate(true);
+  });
+
+  it('should accept a `false` boolean value', () => {
+    Assert.nullOrBoolean().validate(false);
+  });
+});

test/index.test.js

@@ -14,7 +14,7 @@ describe('validator.js-asserts', () => {
   it('should export all asserts', () => {
     const assertNames = Object.keys(asserts);
 
-    expect(assertNames).toHaveLength(35);
+    expect(assertNames).toHaveLength(36);
     expect(assertNames).toEqual(
       expect.arrayContaining([
         'AbaRoutingNumber',
@@ -42,6 +42,7 @@ describe('validator.js-asserts', () => {
         'Iso3166Country',
         'Json',
         'NotEmpty',
+        'NullOrBoolean',
         'NullOrDate',
         'NullOrString',
         'Phone',