▸case-01 I'm working on a Nest.js microservice and getting a dependency injection failure where Nest can't resolve dependencies of my PaymentService. Please inspect my project code to find the missing providers, fix the module configuration, and run all required verification checks to ensure the application compiles and tests pass. | fail→fail | 6,217 | 16,126 | +159% | 1 | 1 | 0% | 282 | 2,095 | +643% | 0 | 0 | — |
▸case-02 Our Nest.js project is throwing a circular dependency error between AuthModule and UserModule. Could you analyze our codebase to locate where the tight coupling happens, refactor the code to break the cycle properly, and run the test suite to confirm everything is fixed? | fail→fail | 4,197 | 5,149 | +23% | 1 | 1 | 0% | 277 | 2,103 | +659% | 0 | 0 | — |
▸case-03 We are integrating Passport JWT auth in our Nest.js app, but all protected endpoints return a 401 Unauthorized missing credentials error. Please audit our strategy, guard, and module bindings, implement the necessary corrections, and validate that the auth flow works completely. | fail→fail | 19,031 | 8,033 | -58% | 1 | 1 | 0% | 4,053 | 2,137 | -47% | 0 | 0 | — |
▸case-04 In our Nest.js project, we have a complex pure TypeScript type mapping utility using generic conditional types type DeepReadonly<T> = ... that fails compiler typechecking with error 'Type instantiation is excessively deep and possibly infinite'. This is purely a TS compiler type inference issue. How do we fix this generic type definition? | fail→pass | 16,622 | 2,295 | -86% | 1 | 1 | 0% | 3,071 | 2,250 | -27% | 0 | 0 | — |
▸case-05 In our Nest.js app, a specific PostgreSQL SQL query with window functions and execution plan issues takes 5 seconds in database engine. We need to optimize PostgreSQL query plan, analyze EXPLAIN ANALYZE output, and add composite B-tree indexes. How should the SQL query and index strategy be optimized? | fail→pass | 23,434 | 2,090 | -91% | 1 | 1 | 0% | 3,575 | 2,179 | -39% | 0 | 0 | — |
▸case-06 Our Node.js server running Nest.js is crashing due to garbage collection allocation failures (ERR_WORKER_OUT_OF_MEMORY) and V8 heap exhaustion during CPU-intensive synchronous crypto hashing in V8 engine. How do we tune V8 CLI flags like --max-old-space-size and analyze event loop lag? | fail→fail | 20,747 | 23,896 | +15% | 1 | 1 | 0% | 3,885 | 6,456 | +66% | 0 | 0 | — |
▸case-07 In a Nest.js application, OrderModule needs to use CatalogService from CatalogModule. A developer suggests putting CatalogModule in the exports array of CatalogModule so all its services are available. Is CatalogModule or CatalogService what should be placed in the exports array? | pass→pass | 7,026 | 8,765 | +25% | 1 | 1 | 0% | 1,428 | 3,480 | +144% | 0 | 0 | — |
▸case-08 When AuthModule and UserModule depend on each other's services in Nest.js, directly importing modules creates undefined dependency errors at runtime. What Nest.js wrapper function must wrap both the `@Module()` imports and constructor `@Inject()` references to break the circular link? | pass→pass | 3,607 | 4,641 | +29% | 1 | 1 | 0% | 690 | 2,694 | +290% | 0 | 0 | — |
▸case-09 We are building a custom Nest.js module `ConfigModule` that loads configuration from an external API at startup. Instead of using `forRoot()` with hardcoded synchronous options, what standard async dynamic module registration method convention should be implemented? | fail→pass | 11,468 | 13,090 | +14% | 1 | 1 | 0% | 2,197 | 4,396 | +100% | 0 | 0 | — |
▸case-10 We want to extract `req.user` inside Nest.js controller handlers using `@User()`. Rather than injecting `REQUEST` object into every service or manually accessing request context in every controller method, which Nest.js factory function creates custom parameter decorators? | pass→pass | 4,677 | 4,352 | -7% | 1 | 1 | 0% | 961 | 2,582 | +169% | 0 | 0 | — |
▸case-11 We need a custom exception filter in Nest.js to intercept `HttpException`. If a class implements `ExceptionFilter` without any class decorators, Nest.js will not catch specific exceptions. What decorator must decorate the filter class? | pass→pass | 3,523 | 3,598 | +2% | 1 | 1 | 0% | 663 | 2,442 | +268% | 0 | 0 | — |
▸case-12 When writing unit tests using `@nestjs/testing` for a service depending on a TypeORM entity repository, using `TypeOrmModule.forRoot()` attempts real database connections during unit tests. How should the entity repository provider be overridden in `Test.createTestingModule()`? | pass→pass | 10,639 | 9,942 | -7% | 1 | 1 | 0% | 2,172 | 3,747 | +73% | 0 | 0 | — |
▸case-13 When verifying a bug fix in Nest.js according to standard quality gates, running e2e tests first is slow and prone to cascading errors. What step should immediately follow unit tests before running e2e tests? | pass→pass | 10,854 | 3,985 | -63% | 1 | 1 | 0% | 1,615 | 2,469 | +53% | 0 | 0 | — |
▸case-14 A Nest.js app throws `Error: secretOrPrivateKey must have a value` on launch when using `JwtModule.register({ secret: process.env.JWT_SECRET })`. Even though `.env` exists, `ConfigModule` loads asynchronously after `JwtModule` registers. How should `JwtModule` registration be modified to defer loading until `ConfigService` is ready? | pass→pass | 6,476 | 7,509 | +16% | 1 | 1 | 0% | 1,316 | 3,286 | +150% | 0 | 0 | — |
▸case-15 During Nest.js e2e testing with `Test.createTestingModule()`, developers often instantiate controller tests without importing full feature modules, causing `Nest can't resolve dependencies` errors for services injected into global guards. How should global module dependencies be resolved in testing module setup? | pass→fail | 15,409 | 15,026 | -2% | 1 | 1 | 0% | 2,827 | 4,867 | +72% | 0 | 0 | — |
▸case-16 A protected Nest.js endpoint using Passport JWT fails with `401 Unauthorized (Missing credentials)`. The developer attempted to extract token from `req.body.token`. Since the client sends `Authorization: Bearer <token>` in HTTP headers, what standard extractor function should be configured in `JwtStrategy`? | pass→pass | 3,169 | 5,834 | +84% | 1 | 1 | 0% | 678 | 2,897 | +327% | 0 | 0 | — |
▸case-17 We want `DatabaseCoreModule` in Nest.js to be available globally without adding it to `imports` in every feature module. Instead of manually importing it into 20 feature modules, what class decorator makes a module globally scoped? | pass→pass | 4,632 | 3,357 | -28% | 1 | 1 | 0% | 676 | 2,382 | +252% | 0 | 0 | — |
▸case-18 In a Nest.js interceptor, modifying response bodies by subscribing directly to the `next.handle()` observable causes unhandled stream side-effects. Which RxJS pipe operator should be returned by the interceptor to map response data cleanly? | pass→pass | 6,444 | 6,637 | +3% | 1 | 1 | 0% | 1,177 | 3,065 | +160% | 0 | 0 | — |
▸case-19 We configured global `ValidationPipe` with `class-validator` in Nest.js. An endpoint expecting `@Query('limit') limit: number` receives string `'10'` at runtime because automatic class transformation is disabled by default. What boolean flag option in `ValidationPipe` forces primitive payload string conversion? | pass→pass | 6,818 | 5,983 | -12% | 1 | 1 | 0% | 1,250 | 2,893 | +131% | 0 | 0 | — |
▸case-20 In a multi-tenant Nest.js application with multiple TypeORM databases, using `@InjectRepository(User)` without parameters defaults to the default connection, causing queries to route to the wrong database. How is the target database connection specified when injecting repositories? | pass→pass | 11,799 | 12,284 | +4% | 1 | 1 | 0% | 2,274 | 4,235 | +86% | 0 | 0 | — |
▸case-21 In Nest.js integration tests using SQLite in-memory database (`:memory:`), creating a new TypeORM connection per test file wipes out the database schema, causing missing table errors. How should the SQLite in-memory database connection be managed across tests to preserve schema? | fail→pass | 15,756 | 18,998 | +21% | 1 | 1 | 0% | 2,971 | 5,405 | +82% | 0 | 0 | — |
▸case-22 When a Nest.js application starts up before PostgreSQL container completes health checks, `TypeOrmModule` immediately fails on first connection attempt and crashes application. What configuration option in `TypeOrmModule` configures automatic connection retry attempts on startup? | pass→pass | 8,231 | 5,987 | -27% | 1 | 1 | 0% | 1,495 | 2,981 | +99% | 0 | 0 | — |
▸case-23 A Nest.js service registers event listeners on an external message queue. When Nest.js application shuts down during zero-downtime deployment, unclosed listeners cause memory leaks in Node.js runtime. What Nest.js lifecycle hook interface should the service implement to unsubscribe before module destruction? | pass→pass | 5,979 | 7,675 | +28% | 1 | 1 | 0% | 1,099 | 3,233 | +194% | 0 | 0 | — |
▸case-24 In Nest.js, a developer attempts to inject a TypeScript interface `Injectable('IUserRepository')` into a constructor, but Nest throws dependency resolution errors because interfaces leave no runtime JS artifact. What non-class token should be passed to `@Inject()` and configured in module providers? | pass→pass | 6,801 | 7,126 | +5% | 1 | 1 | 0% | 1,298 | 3,064 | +136% | 0 | 0 | — |
▸case-25 When presented with a complex Nest.js dependency failure or architecture refactoring task, jumping straight to modifying code without inspecting the project structure often breaks existing modules. What initial phase must be executed first using workspace search tools? | fail→pass | 8,369 | 7,769 | -7% | 1 | 1 | 0% | 1,342 | 3,177 | +137% | 0 | 0 | — |