feat: Add decorator for deregistration of injectables

packages/injectable/index.js

@@ -8,6 +8,7 @@ import lifecycleEnum from './src/dependency-injection-container/lifecycleEnum';
 import createContainer, {
   injectionDecoratorToken,
   registrationDecoratorToken,
+  deregistrationDecoratorToken,
 } from './src/dependency-injection-container/createContainer';
 
 export {
@@ -16,6 +17,7 @@ export {
   getInjectionToken,
   injectionDecoratorToken,
   registrationDecoratorToken,
+  deregistrationDecoratorToken,
   injectionTokenSymbol,
   lifecycleEnum,
 };

packages/injectable/src/dependency-injection-container/createContainer.decoration-of-deregistration.test.js

@@ -0,0 +1,39 @@
+import getInjectable from '../getInjectable/getInjectable';
+import { createContainer } from '../../index';
+import { deregistrationDecoratorToken } from './createContainer';
+
+describe('createContainer.decoration-of-deregistration', () => {
+  describe('given there is decorator for deregistration, when an injectable is deregistered, ', () => {
+    let someInjectable;
+    let di;
+    let deregisterDecoratorMock;
+
+    beforeEach(() => {
+      di = createContainer();
+
+      deregisterDecoratorMock = jest.fn();
+
+      const someDeregistrationDecorator = getInjectable({
+        id: 'some-deregistration-decorator',
+
+        instantiate: () => () => deregisterDecoratorMock,
+
+        injectionToken: deregistrationDecoratorToken,
+      });
+
+      someInjectable = getInjectable({
+        id: 'some-injectable',
+        instantiate: () => 'irrelevant',
+      });
+
+      di.register(someDeregistrationDecorator);
+      di.register(someInjectable);
+    });
+
+    it('when the injectable is deregistered, calls decorator with injectable', () => {
+      di.deregister(someInjectable);
+
+      expect(deregisterDecoratorMock).toHaveBeenCalledWith(someInjectable);
+    });
+  });
+});

packages/injectable/src/dependency-injection-container/createContainer.js

@@ -96,6 +96,10 @@ export default () => {
     nonDecoratedPrivateInjectMany,
   );
 
+  const withDeregistrationDecorators = withDeregistrationDecoratorsFor(
+    nonDecoratedPrivateInjectMany,
+  );
+
   const nonDecoratedRegister = (...externalInjectables) => {
     externalInjectables.forEach(externalInjectable => {
       if (!externalInjectable.id) {
@@ -131,31 +135,33 @@ export default () => {
     injectableMap.get(injectable.id).clear();
   };
 
+  const nonDecoratedDeregister = (...aliases) => {
+    aliases.forEach(alias => {
+      if (!injectableMap.has(alias.id)) {
+        throw new Error(
+          `Tried to deregister non-registered injectable "${alias.id}".`,
+        );
+      }
+
+      purgeInstances(alias);
+
+      injectables = pipeline(injectables, reject(isRelatedTo(alias)));
+
+      overridingInjectables = pipeline(
+        overridingInjectables,
+        reject(isRelatedTo(alias)),
+      );
+    });
+  };
+
   const privateDi = {
     inject: decoratedPrivateInject,
 
     injectMany: decoratedPrivateInjectMany,
 
     register: withRegistrationDecorators(nonDecoratedRegister),
 
-    deregister: (...aliases) => {
-      aliases.forEach(alias => {
-        if (!injectableMap.has(alias.id)) {
-          throw new Error(
-            `Tried to deregister non-registered injectable "${alias.id}".`,
-          );
-        }
-
-        purgeInstances(alias);
-
-        injectables = pipeline(injectables, reject(isRelatedTo(alias)));
-
-        overridingInjectables = pipeline(
-          overridingInjectables,
-          reject(isRelatedTo(alias)),
-        );
-      });
-    },
+    deregister: withDeregistrationDecorators(nonDecoratedDeregister),
 
     override: (alias, instantiateStub) => {
       const originalInjectable = pipeline(
@@ -312,6 +318,11 @@ export const registrationDecoratorToken = getInjectionToken({
   decorable: false,
 });
 
+export const deregistrationDecoratorToken = getInjectionToken({
+  id: 'deregistration-decorator-token',
+  decorable: false,
+});
+
 export const instantiationDecoratorToken = getInjectionToken({
   id: 'instantiate-decorator-token',
   decorable: false,
@@ -331,6 +342,15 @@ const withRegistrationDecoratorsFor =
     pipeline(toBeDecorated, ...decorators)(...injectables);
   };
 
+const withDeregistrationDecoratorsFor =
+  injectMany =>
+  toBeDecorated =>
+  (...injectables) => {
+    const decorators = injectMany(deregistrationDecoratorToken);
+
+    pipeline(toBeDecorated, ...decorators)(...injectables);
+  };
+
 const withInstantiationDecoratorsFor = ({ injectMany, injectable }) => {
   const isRelevantDecorator = isRelevantDecoratorFor(injectable);