test apps api

apps/api/src/shared/testing/httpContractHarness.ts

@@ -0,0 +1,57 @@
+import { ValidationPipe } from '@nestjs/common';
+import type { Provider, Type } from '@nestjs/common';
+import { Test } from '@nestjs/testing';
+import type { TestingModule } from '@nestjs/testing';
+import request from 'supertest';
+
+export type ProviderOverride = {
+  provide: unknown;
+  useValue: unknown;
+};
+
+export type HttpContractHarness = {
+  // Avoid exporting INestApplication here because this repo can end up with
+  // multiple @nestjs/common type roots (workspace hoisting), which makes the
+  // INestApplication types incompatible.
+  app: unknown;
+  module: TestingModule;
+  http: ReturnType<typeof request>;
+  close: () => Promise<void>;
+};
+
+export async function createHttpContractHarness(options: {
+  controllers: Array<Type<unknown>>;
+  providers?: Provider[];
+  overrides?: ProviderOverride[];
+}): Promise<HttpContractHarness> {
+  let moduleBuilder = Test.createTestingModule({
+    controllers: options.controllers,
+    providers: options.providers ?? [],
+  });
+
+  for (const override of options.overrides ?? []) {
+    moduleBuilder = moduleBuilder.overrideProvider(override.provide).useValue(override.useValue);
+  }
+
+  const module = await moduleBuilder.compile();
+  const app = module.createNestApplication();
+
+  app.useGlobalPipes(
+    new ValidationPipe({
+      whitelist: true,
+      forbidNonWhitelisted: true,
+      transform: true,
+    }),
+  );
+
+  await app.init();
+
+  return {
+    app,
+    module,
+    http: request(app.getHttpServer()),
+    close: async () => {
+      await app.close();
+    },
+  };
+}