From afcaeba60efcafcf3d12d5267c1a2911f072266b Mon Sep 17 00:00:00 2001
From: Yousef Soliman <hire@yousefsoliman.com>
Date: Mon, 8 Oct 2018 14:23:12 +0100
Subject: [PATCH 1/2] feat(TinyType): Added new predicate  to check instance
 types

---
 spec/predicates/isInstanceOf.spec.ts | 33 ++++++++++++++++++++++++++++
 src/predicates/index.ts              |  1 +
 src/predicates/isInstanceOf.ts       | 21 ++++++++++++++++++
 3 files changed, 55 insertions(+)
 create mode 100644 spec/predicates/isInstanceOf.spec.ts
 create mode 100644 src/predicates/isInstanceOf.ts

diff --git a/spec/predicates/isInstanceOf.spec.ts b/spec/predicates/isInstanceOf.spec.ts
new file mode 100644
index 00000000..887ec600
--- /dev/null
+++ b/spec/predicates/isInstanceOf.spec.ts
@@ -0,0 +1,33 @@
+import 'mocha';
+import { given } from 'mocha-testdata';
+
+import { ensure, isInstanceOf, TinyType } from '../../src';
+import { expect } from '../expect';
+
+describe('predicates', () => {
+
+    /** @test {isInstanceOf} */
+    describe('::isInstanceOf', () => {
+        class Birthday extends TinyType {
+            constructor(public readonly value: Date) {
+                super();
+
+                ensure('Birthday', value, isInstanceOf(Date));
+            }
+        }
+
+        it('ensures that the argument is an instance of Date', () => {
+            expect(() => new Birthday(new Date())).to.not.throw;              // tslint:disable-line:no-unused-expression
+        });
+
+        given(
+            '2018-10-10',
+            undefined,
+            null,
+            {},
+            'string',
+        ).it('complains if the value does not meet the predicate', (value: any) => {
+            expect(() => new Birthday(value)).to.throw(`Birthday should be instance of Date`);
+        });
+    });
+});
diff --git a/src/predicates/index.ts b/src/predicates/index.ts
index 6a137b88..03f4434f 100644
--- a/src/predicates/index.ts
+++ b/src/predicates/index.ts
@@ -13,6 +13,7 @@ export * from './isLessThanOrEqualTo';
 export * from './isNumber';
 export * from './isOneOf';
 export * from './isString';
+export * from './isInstanceOf';
 export * from './or';
 export * from './Predicate';
 export * from './property';
diff --git a/src/predicates/isInstanceOf.ts b/src/predicates/isInstanceOf.ts
new file mode 100644
index 00000000..e56c1e61
--- /dev/null
+++ b/src/predicates/isInstanceOf.ts
@@ -0,0 +1,21 @@
+import { Predicate } from './Predicate';
+
+/**
+ * @desc Ensures that the `value` is an instance of `type`
+ *
+ * @example
+ * import { ensure, isInstanceOf, TinyType } from 'tiny-types';
+ *
+ * class Birthday extends TinyType {
+ *     constructor(public readonly value: Date) {
+ *         ensure('Date', value, isInstanceOf(Date));
+ *     }
+ * }
+ *
+ * @param {T} value
+ * @param {new (...args: any[]): T} type
+ * @returns {Predicate<T>}
+ */
+export function isInstanceOf<T>(type: { new (...args: any[]): T }): Predicate<T> {
+    return Predicate.to(`be instance of ${type.name}`, (value: T) => value instanceof type);
+}

From 4cee120bc94f09f8894c3db30b3c628aa0114ba6 Mon Sep 17 00:00:00 2001
From: Jan Molak <jan.molak@smartcodeltd.co.uk>
Date: Mon, 8 Oct 2018 15:41:55 +0100
Subject: [PATCH 2/2] docs(predicates): Corrected the jsdoc for isInstance so
 that esdoc doesn't complain

---
 src/predicates/isInstanceOf.ts | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/predicates/isInstanceOf.ts b/src/predicates/isInstanceOf.ts
index e56c1e61..4b293603 100644
--- a/src/predicates/isInstanceOf.ts
+++ b/src/predicates/isInstanceOf.ts
@@ -12,8 +12,7 @@ import { Predicate } from './Predicate';
  *     }
  * }
  *
- * @param {T} value
- * @param {new (...args: any[]): T} type
+ * @param {Constructor<T>} type
  * @returns {Predicate<T>}
  */
 export function isInstanceOf<T>(type: { new (...args: any[]): T }): Predicate<T> {