feat(core): make ExternalsValidator optional for the FeatureServiceRe…

…gistry (#343)

packages/core/src/__tests__/feature-service-registry.test.ts

@@ -43,7 +43,7 @@ describe('FeatureServiceRegistry', () => {
   beforeEach(() => {
     mockExternalsValidator = {validate: jest.fn()};
 
-    featureServiceRegistry = new FeatureServiceRegistry(mockExternalsValidator);
+    featureServiceRegistry = new FeatureServiceRegistry();
 
     featureServiceA = {kind: 'featureServiceA'};
     bindingA = {featureService: featureServiceA};
@@ -131,10 +131,7 @@ describe('FeatureServiceRegistry', () => {
     }
     beforeEach(() => {
       configs = {a: {kind: 'a'}, c: {kind: 'c'}};
-      featureServiceRegistry = new FeatureServiceRegistry(
-        mockExternalsValidator,
-        {configs}
-      );
+      featureServiceRegistry = new FeatureServiceRegistry({configs});
     });
 
     it('registers the Feature Services "a", "b", "c" one after the other', () => {
@@ -339,65 +336,133 @@ describe('FeatureServiceRegistry', () => {
       );
     });
 
-    it('fails to register a Feature Service due to failing externals validation', () => {
-      const mockError = new Error('mockError');
+    describe('without an ExternalsValidator provided to the FeatureServiceRegistry', () => {
+      describe('with a Feature Service definition that is declaring external dependencies', () => {
+        beforeEach(() => {
+          providerDefinitionA = {
+            ...providerDefinitionA,
+            dependencies: {
+              externals: {
+                react: '^16.0.0'
+              }
+            }
+          };
+        });
 
-      mockExternalsValidator.validate = jest.fn(() => {
-        throw mockError;
+        it("doesn't throw an error", () => {
+          expect(() => {
+            featureServiceRegistry.registerFeatureServices(
+              [providerDefinitionA],
+              'test'
+            );
+          }).not.toThrowError();
+        });
       });
+    });
 
-      featureServiceRegistry = new FeatureServiceRegistry(
-        mockExternalsValidator
-      );
+    describe('with an ExternalsValidator provided to the FeatureServiceRegistry', () => {
+      beforeEach(() => {
+        featureServiceRegistry = new FeatureServiceRegistry({
+          externalsValidator: mockExternalsValidator
+        });
+      });
 
-      expect(() => {
-        featureServiceRegistry.registerFeatureServices(
-          [
-            {
-              id: 'failing-externals',
-              create: jest.fn(),
-              dependencies: {
-                externals: {
-                  react: '^16.0.0'
-                }
+      describe('with a Feature Service definition that is failing the externals validation', () => {
+        let mockError: Error;
+
+        beforeEach(() => {
+          mockError = new Error('mockError');
+
+          mockExternalsValidator.validate = jest.fn(() => {
+            throw mockError;
+          });
+
+          providerDefinitionA = {
+            ...providerDefinitionA,
+            dependencies: {
+              externals: {
+                react: '^16.0.0'
               }
             }
-          ],
-          'test'
-        );
-      }).toThrowError(mockError);
+          };
+        });
 
-      expect(mockExternalsValidator.validate).toHaveBeenCalledWith({
-        react: '^16.0.0'
-      });
-    });
+        it('calls the provided ExternalsValidator with the defined externals', () => {
+          try {
+            featureServiceRegistry.registerFeatureServices(
+              [providerDefinitionA],
+              'test'
+            );
+          } catch {}
 
-    it('does not fail to register a Feature Service with valid externals', () => {
-      mockExternalsValidator.validate = jest.fn();
+          expect(mockExternalsValidator.validate).toHaveBeenCalledWith({
+            react: '^16.0.0'
+          });
+        });
 
-      featureServiceRegistry = new FeatureServiceRegistry(
-        mockExternalsValidator
-      );
+        it('throws the validation error', () => {
+          expect(() => {
+            featureServiceRegistry.registerFeatureServices(
+              [providerDefinitionA],
+              'test'
+            );
+          }).toThrowError(mockError);
+        });
+      });
 
-      expect(() => {
-        featureServiceRegistry.registerFeatureServices(
-          [
-            {
-              id: 'with-externals',
-              create: jest.fn(() => ({})),
-              dependencies: {
-                externals: {
-                  react: '^16.0.0'
-                }
+      describe('with a Feature Service definition that is not failing the externals validation', () => {
+        beforeEach(() => {
+          providerDefinitionA = {
+            ...providerDefinitionA,
+            dependencies: {
+              externals: {
+                react: '^16.0.0'
               }
             }
-          ],
-          'test'
-        );
-      }).not.toThrowError();
+          };
+        });
+
+        it('calls the provided ExternalsValidator with the defined externals', () => {
+          try {
+            featureServiceRegistry.registerFeatureServices(
+              [providerDefinitionA],
+              'test'
+            );
+          } catch {}
+
+          expect(mockExternalsValidator.validate).toHaveBeenCalledWith({
+            react: '^16.0.0'
+          });
+        });
+
+        it("doesn't throw an error", () => {
+          expect(() => {
+            featureServiceRegistry.registerFeatureServices(
+              [providerDefinitionA],
+              'test'
+            );
+          }).not.toThrowError();
+        });
+      });
 
-      expect(mockExternalsValidator.validate).toHaveBeenCalledWith({
-        react: '^16.0.0'
+      describe('with a Feature Service definition that declares no externals', () => {
+        it('does not call the provided ExternalsValidator', () => {
+          featureServiceRegistry.registerFeatureServices(
+            [providerDefinitionA],
+            'test'
+          );
+
+          expect(mockExternalsValidator.validate).not.toHaveBeenCalled();
+        });
+
+        it("doesn't throw an error", () => {
+          expect(() => {
+            featureServiceRegistry.registerFeatureServices(
+              [providerDefinitionA],
+              'test'
+            );
+          }).not.toThrowError();
+        });
       });
     });
   });
@@ -416,9 +481,7 @@ describe('FeatureServiceRegistry', () => {
 
     describe('for a Feature Service consumer with an id specifier and dependencies', () => {
       it('creates a bindings object with Feature Services', () => {
-        featureServiceRegistry = new FeatureServiceRegistry(
-          mockExternalsValidator
-        );
+        featureServiceRegistry = new FeatureServiceRegistry();
 
         featureServiceRegistry.registerFeatureServices(
           [providerDefinitionA],
@@ -443,9 +506,7 @@ describe('FeatureServiceRegistry', () => {
 
     describe('for a Feature Service consumer without an id specifier and dependencies', () => {
       it('creates a bindings object with Feature Services', () => {
-        featureServiceRegistry = new FeatureServiceRegistry(
-          mockExternalsValidator
-        );
+        featureServiceRegistry = new FeatureServiceRegistry();
 
         featureServiceRegistry.registerFeatureServices(
           [providerDefinitionA],
@@ -471,9 +532,7 @@ describe('FeatureServiceRegistry', () => {
     describe('for a Feature Service consumer and two optional dependencies', () => {
       describe('with the first dependency missing', () => {
         it('creates a bindings object with Feature Services', () => {
-          featureServiceRegistry = new FeatureServiceRegistry(
-            mockExternalsValidator
-          );
+          featureServiceRegistry = new FeatureServiceRegistry();
 
           featureServiceRegistry.registerFeatureServices(
             [providerDefinitionA],
@@ -498,9 +557,7 @@ describe('FeatureServiceRegistry', () => {
 
       describe('with the second dependency missing', () => {
         it('creates a bindings object with Feature Services', () => {
-          featureServiceRegistry = new FeatureServiceRegistry(
-            mockExternalsValidator
-          );
+          featureServiceRegistry = new FeatureServiceRegistry();
 
           featureServiceRegistry.registerFeatureServices(
             [providerDefinitionA],
@@ -525,9 +582,7 @@ describe('FeatureServiceRegistry', () => {
 
       describe('with no dependency missing', () => {
         it('creates a bindings object with Feature Services', () => {
-          featureServiceRegistry = new FeatureServiceRegistry(
-            mockExternalsValidator
-          );
+          featureServiceRegistry = new FeatureServiceRegistry();
 
           featureServiceRegistry.registerFeatureServices(
             [providerDefinitionA, providerDefinitionB],

packages/core/src/feature-service-registry.ts

@@ -109,6 +109,20 @@ export interface FeatureServiceRegistryOptions {
    * registered.
    */
   readonly configs?: FeatureServiceConfigs;
+
+  /**
+   * If the {@link FeatureAppManager} is configured with a
+   * {@link FeatureAppManager#moduleLoader}, to load Feature Apps from a remote
+   * location that also provide their own Feature Services, i.e. the Feature
+   * Services are included in a different bundle than the integrator bundle, it
+   * might make sense to validate external dependencies that are required by
+   * those Feature Services against the shared dependencies that are provided by
+   * the integrator. This makes it possible that an error is already thrown when
+   * registering a Feature Service with incompatible external dependencies, and
+   * thus enables early feedback as to whether a Feature Service is compatible
+   * with the integration environment.
+   */
+  readonly externalsValidator?: ExternalsValidatorLike;
 }
 
 type ProviderId = string;
@@ -200,7 +214,6 @@ export class FeatureServiceRegistry implements FeatureServiceRegistryLike {
   private readonly consumerUids = new Set<string>();
 
   public constructor(
-    private readonly externalsValidator: ExternalsValidatorLike,
     private readonly options: FeatureServiceRegistryOptions = {}
   ) {}
 
@@ -429,12 +442,18 @@ export class FeatureServiceRegistry implements FeatureServiceRegistryLike {
   }
 
   private validateExternals(
-    consumerDefinition: FeatureServiceConsumerDefinition
+    featureAppDefinition: FeatureServiceConsumerDefinition
   ): void {
-    const {dependencies} = consumerDefinition;
+    const {externalsValidator} = this.options;
+
+    if (!externalsValidator) {
+      return;
+    }
+
+    const {dependencies} = featureAppDefinition;
 
     if (dependencies && dependencies.externals) {
-      this.externalsValidator.validate(dependencies.externals);
+      externalsValidator.validate(dependencies.externals);
     }
   }
 

packages/demos/src/feature-app-in-feature-app/integrator.node.tsx

@@ -18,7 +18,10 @@ export default async function renderApp({
   });
 
   const featureAppNodeUrl = `http://localhost:${port}/feature-app.commonjs.js`;
-  const featureServiceRegistry = new FeatureServiceRegistry(externalsValidator);
+
+  const featureServiceRegistry = new FeatureServiceRegistry({
+    externalsValidator
+  });
 
   const featureAppManager = new FeatureAppManager(featureServiceRegistry, {
     moduleLoader: loadCommonJsModule,

packages/demos/src/feature-app-in-feature-app/integrator.tsx

@@ -19,7 +19,7 @@ const externalsValidator = new ExternalsValidator({
   '@feature-hub/react': '0.12.0'
 });
 
-const featureServiceRegistry = new FeatureServiceRegistry(externalsValidator);
+const featureServiceRegistry = new FeatureServiceRegistry({externalsValidator});
 
 const featureAppManager = new FeatureAppManager(featureServiceRegistry, {
   moduleLoader: loadAmdModule,

packages/demos/src/history-service/integrator.node.tsx

@@ -1,8 +1,4 @@
-import {
-  ExternalsValidator,
-  FeatureAppManager,
-  FeatureServiceRegistry
-} from '@feature-hub/core';
+import {FeatureAppManager, FeatureServiceRegistry} from '@feature-hub/core';
 import {defineHistoryService} from '@feature-hub/history-service';
 import {defineServerRequest} from '@feature-hub/server-request';
 import * as React from 'react';
@@ -14,8 +10,7 @@ import {rootLocationTransformer} from './root-location-transformer';
 export default async function renderApp({
   req
 }: AppRendererOptions): Promise<AppRendererResult> {
-  const externalsValidator = new ExternalsValidator({});
-  const featureServiceRegistry = new FeatureServiceRegistry(externalsValidator);
+  const featureServiceRegistry = new FeatureServiceRegistry();
 
   const featureServiceDefinitions = [
     defineServerRequest(req),

packages/demos/src/history-service/integrator.tsx

@@ -1,17 +1,12 @@
-import {
-  ExternalsValidator,
-  FeatureAppManager,
-  FeatureServiceRegistry
-} from '@feature-hub/core';
+import {FeatureAppManager, FeatureServiceRegistry} from '@feature-hub/core';
 import {defineHistoryService} from '@feature-hub/history-service';
 import * as React from 'react';
 import * as ReactDOM from 'react-dom';
 import '../blueprint-css';
 import {App} from './app';
 import {rootLocationTransformer} from './root-location-transformer';
 
-const externalsValidator = new ExternalsValidator({});
-const featureServiceRegistry = new FeatureServiceRegistry(externalsValidator);
+const featureServiceRegistry = new FeatureServiceRegistry();
 
 featureServiceRegistry.registerFeatureServices(
   [defineHistoryService(rootLocationTransformer)],

packages/demos/src/module-loader-amd/integrator.tsx

@@ -15,7 +15,7 @@ const externalsValidator = new ExternalsValidator({
   react: '16.7.0'
 });
 
-const featureServiceRegistry = new FeatureServiceRegistry(externalsValidator);
+const featureServiceRegistry = new FeatureServiceRegistry({externalsValidator});
 
 const featureAppManager = new FeatureAppManager(featureServiceRegistry, {
   moduleLoader: loadAmdModule,

packages/demos/src/module-loader-commonjs/integrator.node.tsx

@@ -1,8 +1,4 @@
-import {
-  ExternalsValidator,
-  FeatureAppManager,
-  FeatureServiceRegistry
-} from '@feature-hub/core';
+import {FeatureAppManager, FeatureServiceRegistry} from '@feature-hub/core';
 import {loadCommonJsModule} from '@feature-hub/module-loader-commonjs';
 import {FeatureAppLoader, FeatureHubContextProvider} from '@feature-hub/react';
 import * as React from 'react';
@@ -13,8 +9,7 @@ export default async function renderApp({
   port
 }: AppRendererOptions): Promise<AppRendererResult> {
   const featureAppNodeUrl = `http://localhost:${port}/feature-app.commonjs.js`;
-  const externalsValidator = new ExternalsValidator({});
-  const featureServiceRegistry = new FeatureServiceRegistry(externalsValidator);
+  const featureServiceRegistry = new FeatureServiceRegistry();
 
   const featureAppManager = new FeatureAppManager(featureServiceRegistry, {
     moduleLoader: loadCommonJsModule