From 4500f33ae9eaf8756879ffe586c22afda61ab428 Mon Sep 17 00:00:00 2001
From: Tobe O <thosakwe@gmail.com>
Date: Sun, 26 Aug 2018 18:55:21 -0400
Subject: [PATCH] add Container.has<T>

---
 angel_container/CHANGELOG.md           |  3 ++
 angel_container/lib/src/container.dart | 31 ++++++++++++-------
 angel_container/pubspec.yaml           |  2 +-
 angel_container/test/has_test.dart     | 42 ++++++++++++++++++++++++++
 4 files changed, 66 insertions(+), 12 deletions(-)
 create mode 100644 angel_container/test/has_test.dart

diff --git a/angel_container/CHANGELOG.md b/angel_container/CHANGELOG.md
index 08bf944b..c0458ccf 100644
--- a/angel_container/CHANGELOG.md
+++ b/angel_container/CHANGELOG.md
@@ -1,3 +1,6 @@
+# 1.0.0-alpha.9
+* Added `Container.has<T>`.
+
 # 1.0.0-alpha.8
 * Fixed a bug where `_ReflectedTypeInstance.isAssignableTo` always failed.
 * Added `@GenerateReflector` annotation.
diff --git a/angel_container/lib/src/container.dart b/angel_container/lib/src/container.dart
index 19844b0e..38ecf942 100644
--- a/angel_container/lib/src/container.dart
+++ b/angel_container/lib/src/container.dart
@@ -20,6 +20,23 @@ class Container {
     return new Container._child(this);
   }
 
+  bool has<T>([Type t]) {
+    var search = this;
+    t ??= T == dynamic ? t : T;
+
+    while (search != null) {
+      if (search._singletons.containsKey(t)) {
+        return true;
+      } else if (search._factories.containsKey(t)) {
+        return true;
+      } else {
+        search = search._parent;
+      }
+    }
+
+    return false;
+  }
+
   /// Instantiates an instance of [T].
   ///
   /// In contexts where a static generic type cannot be used, use
@@ -27,22 +44,14 @@ class Container {
   T make<T>([Type type]) {
     type ??= T;
 
-    // Find a singleton, if any.
     var search = this;
 
     while (search != null) {
       if (search._singletons.containsKey(type)) {
+        // Find a singleton, if any.
         return search._singletons[type] as T;
-      } else {
-        search = search._parent;
-      }
-    }
-
-    // Find a factory, if any.
-    search = this;
-
-    while (search != null) {
-      if (search._factories.containsKey(type)) {
+      } else if (search._factories.containsKey(type)) {
+        // Find a factory, if any.
         return search._factories[type](this) as T;
       } else {
         search = search._parent;
diff --git a/angel_container/pubspec.yaml b/angel_container/pubspec.yaml
index a1417fe2..e9717ef1 100644
--- a/angel_container/pubspec.yaml
+++ b/angel_container/pubspec.yaml
@@ -1,5 +1,5 @@
 name: angel_container
-version: 1.0.0-alpha.8
+version: 1.0.0-alpha.9
 author: Tobe O <thosakwe@gmail.com>
 description: "A better IoC container and dependency injector for Angel, ultimately allowing Angel to be used without dart:mirrors."
 homepage: https://github.com/angel-dart/container.git
diff --git a/angel_container/test/has_test.dart b/angel_container/test/has_test.dart
new file mode 100644
index 00000000..0a831c19
--- /dev/null
+++ b/angel_container/test/has_test.dart
@@ -0,0 +1,42 @@
+import 'package:angel_container/angel_container.dart';
+import 'package:test/test.dart';
+
+void main() {
+  Container container;
+
+  setUp(() {
+    container = new Container(const EmptyReflector())
+      ..registerSingleton<Song>(new Song(title: 'I Wish'))
+      ..registerFactory<Artist>((container) {
+        return new Artist(
+          name: 'Stevie Wonder',
+          song: container.make<Song>(),
+        );
+      });
+  });
+
+  test('has on singleton', () {
+    expect(container.has<Song>(), true);
+  });
+
+  test('has on factory', () {
+    expect(container.has<Artist>(), true);
+  });
+
+  test('false if neither', () {
+    expect(container.has<bool>(), false);
+  });
+}
+
+class Artist {
+  final String name;
+  final Song song;
+
+  Artist({this.name, this.song});
+}
+
+class Song {
+  final String title;
+
+  Song({this.title});
+}