allow to create the instantiation service with a strict flag such that it throw on missing services, #5653

src/vs/platform/instantiation/common/instantiationService.ts

@@ -19,9 +19,11 @@ export class InstantiationService implements IInstantiationService {
 	serviceId: any;
 
 	private _services: ServiceCollection;
+	private _strict: boolean;
 
-	constructor(services: ServiceCollection = new ServiceCollection()) {
+	constructor(services: ServiceCollection = new ServiceCollection(), strict: boolean = false) {
 		this._services = services;
+		this._strict = strict;
 
 		this._services.set(IInstantiationService, this);
 	}
@@ -32,7 +34,7 @@ export class InstantiationService implements IInstantiationService {
 				services.set(id, thing);
 			}
 		});
-		return new InstantiationService(services);
+		return new InstantiationService(services, this._strict);
 	}
 
 	invokeFunction<R>(signature: (accessor: ServicesAccessor, ...more: any[]) => R, ...args: any[]): R {
@@ -113,9 +115,9 @@ export class InstantiationService implements IInstantiationService {
 		let serviceDependencies = _util.getServiceDependencies(desc.ctor).sort((a, b) => a.index - b.index);
 		let serviceArgs = serviceDependencies.map(dependency => {
 			let service = this._getOrCreateServiceInstance(dependency.id);
-			// if (!service && !dependency.optional) {
-			// 	throw new Error(`[createInstance] ${desc.ctor.name} depends on UNKNOWN service ${dependency.id}.`);
-			// }
+			if (!service && this._strict && !dependency.optional) {
+				throw new Error(`[createInstance] ${desc.ctor.name} depends on UNKNOWN service ${dependency.id}.`);
+			}
 			return service;
 		});
 		let firstServiceArgPos = serviceDependencies.length > 0 ? serviceDependencies[0].index : staticArgs.length;

src/vs/platform/instantiation/test/common/instantiationService.test.ts

@@ -87,12 +87,12 @@ class TargetWithStaticParam {
 	}
 }
 
-class TargetOptional1 {
+class TargetNotOptional {
 	constructor( @IService1 service1: IService1, @IService2 service2: IService2) {
-		assert.ok(false, 'should not be here');
+
 	}
 }
-class TargetOptional2 {
+class TargetOptional {
 	constructor( @IService1 service1: IService1, @optional(IService2) service2: IService2) {
 		assert.ok(service1);
 		assert.equal(service1.c, 1);
@@ -200,13 +200,15 @@ suite('Instantiation Service', () => {
 	});
 
 	test('@Param - optional', function () {
-		let collection = new ServiceCollection();
-		let service = new InstantiationService(collection);
-		collection.set(IService1, new Service1());
-		// service.addSingleton(IService2, new Service2());
+		let collection = new ServiceCollection([IService1, new Service1()]);
+		let service = new InstantiationService(collection, true);
 
-		// assert.throws(() => service.createInstance(TargetOptional1));
-		service.createInstance(TargetOptional2);
+		service.createInstance(TargetOptional);
+		assert.throws(() => service.createInstance(TargetNotOptional));
+
+		service = new InstantiationService(collection, false);
+		service.createInstance(TargetOptional);
+		service.createInstance(TargetNotOptional);
 	});
 
 	// we made this a warning