shancheas
0550cbe764
- Introduced `@Pagination()` decorator to mark list endpoints for pagination.
- Added `TransformInterceptor` to wrap responses in a standardized format `{ data, meta }`.
- Created pagination-related utility functions and constants for managing pagination logic.
- Defined `PaginationQueryDto` for handling pagination query parameters.
- Established `PaginationMetaDto` for OpenAPI documentation of pagination metadata.
- Updated existing controller and service structures to support pagination in responses.
- Added unit tests for pagination utilities and interceptor to ensure correct functionality.
59 lines
1.6 KiB
TypeScript
59 lines
1.6 KiB
TypeScript
import {
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CallHandler,
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ExecutionContext,
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Injectable,
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NestInterceptor,
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StreamableFile,
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} from '@nestjs/common';
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import { Reflector } from '@nestjs/core';
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import { Observable } from 'rxjs';
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import { map } from 'rxjs/operators';
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import { PAGINATION_RESPONSE, RAW_RESPONSE } from './constants';
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import {
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createPaginationResponse,
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resolvePaginationQuery,
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} from './pagination-meta.helper';
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/**
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* Applies pagination enveloping when a handler is marked with `@Pagination()`.
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*
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* Non-paginated handlers pass through unchanged. `@RawResponse()`, empty
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* bodies, and `StreamableFile` downloads are never wrapped.
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*/
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@Injectable()
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export class TransformInterceptor implements NestInterceptor {
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constructor(private readonly reflector: Reflector) {}
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intercept(context: ExecutionContext, next: CallHandler): Observable<unknown> {
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const isRaw = this.reflector.getAllAndOverride<boolean>(RAW_RESPONSE, [
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context.getHandler(),
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context.getClass(),
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]);
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if (isRaw) {
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return next.handle();
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}
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const isPagination = this.reflector.getAllAndOverride<boolean>(
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PAGINATION_RESPONSE,
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[context.getHandler(), context.getClass()],
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);
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if (!isPagination) {
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return next.handle();
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}
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const request = context.switchToHttp().getRequest<{
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query: Record<string, unknown>;
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}>();
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const { page, limit } = resolvePaginationQuery(request.query);
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return next.handle().pipe(
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map((payload: unknown): unknown => {
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if (payload == null || payload instanceof StreamableFile) {
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return payload;
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}
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return createPaginationResponse(payload, page, limit);
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}),
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);
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}
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}
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