feat: Create an OperationRouterHandler

This allows us to route after an Operation has been parsed

test/unit/server/util/OperationRouterHandler.test.ts

@@ -0,0 +1,44 @@
+import type { Operation } from '../../../../src/http/Operation';
+import { BasicRepresentation } from '../../../../src/http/representation/BasicRepresentation';
+import type { HttpRequest } from '../../../../src/server/HttpRequest';
+import type { HttpResponse } from '../../../../src/server/HttpResponse';
+import type { OperationHttpHandler } from '../../../../src/server/OperationHttpHandler';
+import { OperationRouterHandler } from '../../../../src/server/util/OperationRouterHandler';
+
+describe('An OperationRouterHandler', (): void => {
+  const request: HttpRequest = {} as any;
+  const response: HttpResponse = {} as any;
+  let operation: Operation;
+  let handler: jest.Mocked<OperationHttpHandler>;
+  let router: OperationRouterHandler;
+
+  beforeEach(async(): Promise<void> => {
+    operation = {
+      method: 'GET',
+      target: { path: 'http://example.com/foo' },
+      preferences: {},
+      body: new BasicRepresentation(),
+    };
+
+    handler = {
+      canHandle: jest.fn(),
+      handle: jest.fn(),
+    } as any;
+
+    router = new OperationRouterHandler({
+      baseUrl: 'http://example.com/',
+      handler,
+      allowedPathNames: [ '^/foo$' ],
+      allowedMethods: [ 'GET' ],
+    });
+  });
+
+  it('passes the operation values.', async(): Promise<void> => {
+    await expect(router.canHandle({ operation, request, response })).resolves.toBeUndefined();
+    operation.method = 'POST';
+    await expect(router.canHandle({ operation, request, response })).rejects.toThrow('POST is not allowed.');
+    operation.method = 'GET';
+    operation.target = { path: 'http://example.com/wrong' };
+    await expect(router.canHandle({ operation, request, response })).rejects.toThrow('Cannot handle route /wrong');
+  });
+});