Add support for timestamp on date assert

src/asserts/date-assert.js

@@ -21,12 +21,24 @@ export default function dateAssert() {
    */
 
   this.validate = value => {
-    if (typeof value !== 'string' && Object.prototype.toString.call(value) !== '[object Date]') {
-      throw new Violation(this, value, { value: 'must_be_a_date_or_a_string' });
+    if (typeof value === 'string') {
+      if (isNaN(Date.parse(value)) === true) {
+        throw new Violation(this, value);
+      }
+
+      return true;
+    }
+
+    if (typeof value === 'number') {
+      if (new Date(value).getTime() < 0) {
+        throw new Violation(this, value);
+      }
+
+      return true;
     }
 
-    if (isNaN(Date.parse(value)) === true) {
-      throw new Violation(this, value);
+    if (Object.prototype.toString.call(value) !== '[object Date]') {
+      throw new Violation(this, value, { value: 'must_be_a_date_or_a_string_or_a_timestamp' });
     }
 
     return true;

test/asserts/date-assert_test.js

@@ -19,9 +19,9 @@ const Assert = BaseAssert.extend({
  * Test `DateAssert`.
  */
 
-describe('DateAssert', () => {
-  it('should throw an error if the input value is not a string or a date', () => {
-    const choices = [[], {}, 123];
+describe.only('DateAssert', () => {
+  it('should throw an error if the input value is not a date or a string or a timestamp', () => {
+    const choices = [[], {}];
 
     choices.forEach(choice => {
       try {
@@ -30,7 +30,7 @@ describe('DateAssert', () => {
         should.fail();
       } catch (e) {
         e.should.be.instanceOf(Violation);
-        e.violation.value.should.equal('must_be_a_date_or_a_string');
+        e.violation.value.should.equal('must_be_a_date_or_a_string_or_a_timestamp');
       }
     });
   });
@@ -52,4 +52,8 @@ describe('DateAssert', () => {
   it('should accept a `string`', () => {
     new Assert().Date().validate('2014-10-16');
   });
+
+  it('should accept a `timestamp`', () => {
+    new Assert().Date().validate(Date.now());
+  });
 });