Adding Angular's DI package & Dart unittests which test it.

third_party/pkg/di/test/main.dart

+@Injectables(const [
+  ClassOne,
+  CircularA,
+  CircularB,
+  MultipleConstructors,
+  NumDependency,
+  IntDependency,
+  DoubleDependency,
+  BoolDependency,
+  StringDependency
+])
+library di.tests;
+
+import 'fixed-unittest.dart';
+import 'package:di/di.dart';
+import 'package:di/dynamic_injector.dart';
+import 'package:di/static_injector.dart';
+import 'package:di/annotations.dart';
+
+// Generated file. Run ../test_tf_gen.sh.
+import 'type_factories_gen.dart' as type_factories_gen;
+
+/**
+ * Annotation used to mark classes for which static type factory must be
+ * generated. For testing purposes not all classes are marked with this
+ * annotation, some classes are included in @Injectables at the top.
+ */
+class Injectable {
+  const Injectable();
+}
+
+// just some classes for testing
+@Injectable()
+class Engine {
+  String id = 'v8-id';
+}
+
+@Injectable()
+class MockEngine implements Engine {
+  String id = 'mock-id';
+}
+
+@Injectable()
+class MockEngine2 implements Engine {
+  String id = 'mock-id-2';
+}
+
+@Injectable()
+class Car {
+  Engine engine;
+  Injector injector;
+
+  Car(this.engine, this.injector);
+}
+
+class NumDependency {
+  NumDependency(num value) {}
+}
+
+class IntDependency {
+  IntDependency(int value) {}
+}
+
+class DoubleDependency {
+  DoubleDependency(double value) {}
+}
+
+class StringDependency {
+  StringDependency(String value) {}
+}
+
+class BoolDependency {
+  BoolDependency(bool value) {}
+}
+
+
+class CircularA {
+  CircularA(CircularB b) {}
+}
+
+class CircularB {
+  CircularB(CircularA a) {}
+}
+
+typedef int CompareInt(int a, int b);
+
+int compareIntAsc(int a, int b) => b.compareTo(a);
+
+class WithTypeDefDependency {
+  CompareInt compare;
+
+  WithTypeDefDependency(CompareInt c) {
+    compare = c;
+  }
+}
+
+class MultipleConstructors {
+  String instantiatedVia;
+  MultipleConstructors() : instantiatedVia = 'default';
+  MultipleConstructors.named() : instantiatedVia = 'named';
+}
+
+class InterfaceOne {
+}
+
+class ClassOne implements InterfaceOne {
+  ClassOne(Log log) {
+    log.add('ClassOne');
+  }
+}
+
+@Injectable()
+class Log {
+  var log = [];
+
+  add(String message) => log.add(message);
+}
+
+class EmulatedMockEngineFactory {
+  call(Injector i) => new MockEngine();
+}
+
+void main() {
+  createInjectorSpec('DynamicInjector',
+      (modules, [name]) => new DynamicInjector(modules: modules, name: name));
+
+  // Initialize generated type factories.
+  type_factories_gen.main();
+
+  createInjectorSpec('StaticInjector',
+      (modules, [name]) => new StaticInjector(modules: modules, name: name,
+          typeFactories: type_factories_gen.typeFactories));
+}
+
+typedef Injector InjectorFactory(List<Module> modules, [String name]);
+
+createInjectorSpec(String injectorName, InjectorFactory injectorFactory) {
+
+  describe(injectorName, () {
+
+    it('should instantiate a type', () {
+      var injector = injectorFactory([new Module()..type(Engine)]);
+      var instance = injector.get(Engine);
+
+      expect(instance, instanceOf(Engine));
+      expect(instance.id, toEqual('v8-id'));
+    });
+
+    it('should fail if no binding is found', () {
+      var injector = injectorFactory([]);
+      expect(() {
+        injector.get(Engine);
+      }, toThrow(NoProviderError, 'No provider found for Engine! '
+      '(resolving Engine)'));
+    });
+
+
+    it('should resolve basic dependencies', () {
+      var injector = injectorFactory([new Module()..type(Car)..type(Engine)]);
+      var instance = injector.get(Car);
+
+      expect(instance, instanceOf(Car));
+      expect(instance.engine.id, toEqual('v8-id'));
+    });
+
+
+    it('should allow modules and overriding providers', () {
+      var module = new Module()..type(Engine, implementedBy: MockEngine);
+
+      // injector is immutable
+      // you can't load more modules once it's instantiated
+      // (you can create a child injector)
+      var injector = injectorFactory([module]);
+      var instance = injector.get(Engine);
+
+      expect(instance.id, toEqual('mock-id'));
+    });
+
+
+    it('should only create a single instance', () {
+      var injector = injectorFactory([new Module()..type(Engine)]);
+      var first = injector.get(Engine);
+      var second = injector.get(Engine);
+
+      expect(first, toBe(second));
+    });
+
+
+    it('should allow providing values', () {
+      var module = new Module()
+        ..value(Engine, 'str value')
+        ..value(Car, 123);
+
+      var injector = injectorFactory([module]);
+      var abcInstance = injector.get(Engine);
+      var complexInstance = injector.get(Car);
+
+      expect(abcInstance, toEqual('str value'));
+      expect(complexInstance, toEqual(123));
+    });
+
+
+    it('should allow providing factory functions', () {
+      var module = new Module()..factory(Engine, (Injector injector) {
+        return 'factory-product';
+      });
+
+      var injector = injectorFactory([module]);
+      var instance = injector.get(Engine);
+
+      expect(instance, toEqual('factory-product'));
+    });
+
+
+    it('should allow providing with emulated factory functions', () {
+      var module = new Module();
+      module.factory(Engine, new EmulatedMockEngineFactory());
+
+      var injector = injectorFactory([module]);
+      var instance = injector.get(Engine);
+
+      expect(instance, new isInstanceOf<MockEngine>());
+    });
+
+
+    it('should inject injector into factory function', () {
+      var module = new Module()
+        ..type(Engine)
+        ..factory(Car, (Injector injector) {
+        return new Car(injector.get(Engine), injector);
+      });
+
+      var injector = injectorFactory([module]);
+      var instance = injector.get(Car);
+
+      expect(instance, instanceOf(Car));
+      expect(instance.engine.id, toEqual('v8-id'));
+    });
+
+
+    it('should throw an exception when injecting a primitive type', () {
+      var injector = injectorFactory([
+        new Module()
+          ..type(NumDependency)
+          ..type(IntDependency)
+          ..type(DoubleDependency)
+          ..type(BoolDependency)
+          ..type(StringDependency)
+      ]);
+
+      expect(() {
+        injector.get(NumDependency);
+      }, toThrow(NoProviderError, 'Cannot inject a primitive type of num! '
+      '(resolving NumDependency -> num)'));
+
+      expect(() {
+        injector.get(IntDependency);
+      }, toThrow(NoProviderError, 'Cannot inject a primitive type of int! '
+      '(resolving IntDependency -> int)'));
+
+      expect(() {
+        injector.get(DoubleDependency);
+      }, toThrow(NoProviderError, 'Cannot inject a primitive type of double! '
+      '(resolving DoubleDependency -> double)'));
+
+      expect(() {
+        injector.get(BoolDependency);
+      }, toThrow(NoProviderError, 'Cannot inject a primitive type of bool! '
+      '(resolving BoolDependency -> bool)'));
+
+      expect(() {
+        injector.get(StringDependency);
+      }, toThrow(NoProviderError, 'Cannot inject a primitive type of String! '
+      '(resolving StringDependency -> String)'));
+    });
+
+
+    it('should throw an exception when circular dependency', () {
+      var injector = injectorFactory([new Module()..type(CircularA)..type(CircularB)]);
+
+      expect(() {
+        injector.get(CircularA);
+      }, toThrow(CircularDependencyError, 'Cannot resolve a circular dependency! '
+          '(resolving CircularA -> '
+      'CircularB -> CircularA)'));
+    });
+
+
+    it('should provide the injector as Injector', () {
+      var injector = injectorFactory([]);
+
+      expect(injector.get(Injector), toBe(injector));
+    });
+
+
+    // Typedef injection is not supported in dart2js: http://dartbug.com/11612
+    xit('should inject a typedef', () {
+      var module = new Module()..value(CompareInt, compareIntAsc);
+
+      var injector = injectorFactory([module]);
+      var compare = injector.get(CompareInt);
+
+      expect(compare(1, 2), toBe(1));
+      expect(compare(5, 2), toBe(-1));
+    });
+
+
+    // Typedef injection is not supported in dart2js: http://dartbug.com/11612
+    xit('should throw an exception when injecting typedef without providing it', () {
+      var injector = injectorFactory([new Module()..type(WithTypeDefDependency)]);
+
+      expect(() {
+        injector.get(WithTypeDefDependency);
+      }, toThrow(NoProviderError, 'No provider found for CompareInt! '
+      '(resolving WithTypeDefDependency -> CompareInt)'));
+    });
+
+
+    it('should instantiate via the default/unnamed constructor', () {
+      var injector = injectorFactory([new Module()..type(MultipleConstructors)]);
+      MultipleConstructors instance = injector.get(MultipleConstructors);
+      expect(instance.instantiatedVia, 'default');
+    });
+
+    // CHILD INJECTORS
+    it('should inject from child', () {
+      var module = new Module()..type(Engine, implementedBy: MockEngine);
+
+      var parent = injectorFactory([new Module()..type(Engine)]);
+      var child = parent.createChild([module]);
+
+      var abcFromParent = parent.get(Engine);
+      var abcFromChild = child.get(Engine);
+
+      expect(abcFromParent.id, toEqual('v8-id'));
+      expect(abcFromChild.id, toEqual('mock-id'));
+    });
+
+
+    it('should enumerate across children', () {
+      var parent = injectorFactory([new Module()..type(Engine)]);
+      var child = parent.createChild([new Module()..type(MockEngine)]);
+
+      expect(parent.types, unorderedEquals(new Set.from([Engine, Injector])));
+      expect(child.types, unorderedEquals(new Set.from([Engine, MockEngine, Injector])));
+    });
+
+
+    it('should inject instance from parent if not provided in child', () {
+      var module = new Module()..type(Car);
+
+      var parent = injectorFactory([new Module()..type(Car)..type(Engine)]);
+      var child = parent.createChild([module]);
+
+      var complexFromParent = parent.get(Car);
+      var complexFromChild = child.get(Car);
+      var abcFromParent = parent.get(Engine);
+      var abcFromChild = child.get(Engine);
+
+      expect(complexFromChild, not(toBe(complexFromParent)));
+      expect(abcFromChild, toBe(abcFromParent));
+    });
+
+
+    it('should inject instance from parent but never use dependency from child', () {
+      var module = new Module()..type(Engine, implementedBy: MockEngine);
+
+      var parent = injectorFactory([new Module()..type(Car)..type(Engine)]);
+      var child = parent.createChild([module]);
+
+      var complexFromParent = parent.get(Car);
+      var complexFromChild = child.get(Car);
+      var abcFromParent = parent.get(Engine);
+      var abcFromChild = child.get(Engine);
+
+      expect(complexFromChild, toBe(complexFromParent));
+      expect(complexFromChild.engine, toBe(abcFromParent));
+      expect(complexFromChild.engine, not(toBe(abcFromChild)));
+    });
+
+
+    it('should force new instance in child even if already instantiated in parent', () {
+      var parent = injectorFactory([new Module()..type(Engine)]);
+      var abcAlreadyInParent = parent.get(Engine);
+
+      var child = parent.createChild([], forceNewInstances: [Engine]);
+      var abcFromChild = child.get(Engine);
+
+      expect(abcFromChild, not(toBe(abcAlreadyInParent)));
+    });
+
+
+    it('should force new instance in child using provider from grand parent', () {
+      var module = new Module()..type(Engine, implementedBy: MockEngine);
+
+      var grandParent = injectorFactory([module]);
+      var parent = grandParent.createChild([]);
+      var child = parent.createChild([], forceNewInstances: [Engine]);
+
+      var abcFromGrandParent = grandParent.get(Engine);
+      var abcFromChild = child.get(Engine);
+
+      expect(abcFromChild.id, toEqual(('mock-id')));
+      expect(abcFromChild, not(toBe(abcFromGrandParent)));
+    });
+
+
+    it('should provide child injector as Injector', () {
+      var injector = injectorFactory([]);
+      var child = injector.createChild([]);
+
+      expect(child.get(Injector), toBe(child));
+    });
+
+
+    it('should set the injector name', () {
+      var injector = injectorFactory([], 'foo');
+      expect(injector.name, 'foo');
+    });
+
+
+    it('should set the child injector name', () {
+      var injector = injectorFactory([], 'foo');
+      var childInjector = injector.createChild(null, name: 'bar');
+      expect(childInjector.name, 'bar');
+    });
+
+
+    it('should instantiate class only once (Issue #18)', () {
+      var injector = injectorFactory([
+          new Module()
+            ..type(Log)
+            ..type(ClassOne)
+            ..factory(InterfaceOne, (i) => i.get(ClassOne))
+      ]);
+
+      expect(injector.get(InterfaceOne), same(injector.get(ClassOne)));
+      expect(injector.get(Log).log.join(' '), 'ClassOne');
+    });
+
+
+    describe('creation strategy', () {
+
+      it('should get called for instance creation', () {
+
+        List creationLog = [];
+        dynamic creation(Injector requesting, Injector defining, factory) {
+          creationLog.add([requesting, defining]);
+          return factory();
+        }
+
+        var parentModule = new Module()
+          ..type(Engine, implementedBy: MockEngine, creation: creation)
+          ..type(Car, creation: creation);
+
+        var parentInjector = injectorFactory([parentModule]);
+        var childInjector = parentInjector.createChild([]);
+        childInjector.get(Car);
+        expect(creationLog, [
+          [childInjector, parentInjector],
+          [childInjector, parentInjector]
+        ]);
+      });
+
+      it('should be able to prevent instantiation', () {
+
+        List creationLog = [];
+        dynamic creation(Injector requesting, Injector defining, factory) {
+          throw 'not allowing';
+        }
+
+        var module = new Module()
+          ..type(Engine, implementedBy: MockEngine, creation: creation);
+        var injector = injectorFactory([module]);
+        expect(() {
+          injector.get(Engine);
+        }, throwsA('not allowing'));
+      });
+    });
+
+
+    describe('visiblity', () {
+
+      it('should hide instances', () {
+
+        var rootMock = new MockEngine();
+        var childMock = new MockEngine();
+
+        var parentModule = new Module()
+          ..value(Engine, rootMock);
+        var childModule = new Module()
+          ..value(Engine, childMock, visibility: (_, __) => false);
+
+        var parentInjector = injectorFactory([parentModule]);
+        var childInjector = parentInjector.createChild([childModule]);
+
+        var val = childInjector.get(Engine);
+        expect(val, same(rootMock));
+      });
+
+      it('should throw when an instance in not visible in the root injector', () {
+        var module = new Module()
+          ..value(Car, 'Invisible', visibility: (_, __) => false);
+
+        var injector = injectorFactory([module]);
+
+        expect(() {
+          injector.get(Car);
+        }, toThrow(
+            NoProviderError,
+            'No provider found for Car! (resolving Car)'
+        ));
+      });
+
+    });
+
+  });
+
+}