zod-validation.pipe.ts

zod-validation.pipe.tsapps/api/src/common/pipes/zod-validation.pipe.tsraw ← pipes2,295 B← Back to the app
1import { ArgumentMetadata, Injectable, PipeTransform } from "@nestjs/common";
2import { z, type ZodTypeAny } from "zod";
3import { ApiError } from "../errors.js";
4 
5/**
6 * Zod validation pipe.
7 *
8 *   @Body(ZodValidate(schema)) body
9 *   @Query(ZodValidate(querySchema)) query
10 *   @Params(ZodValidate(paramsSchema)) params
11 *
12 * Parses the raw input against the schema (with `.parse`) and returns the
13 * transformed/validated object; failures throw VALIDATION_ERROR with
14 * field-level details — handled by the global filter into the canonical
15 * {error:{code:"VALIDATION_ERROR",details:[...]}} envelope.
16 *
17 * NOTE: constructed manually by the `ZodValidate` factory below — it is
18 * `@Injectable()`-marked but NEVER provided to Nest DI, so its ctor takes
19 * no `@Inject` (the schema is a value, not a DI token; TASK-0100 S0).
20 */
21@Injectable()
22// Declared as `Promise<T>` because `transform` is `async` (it returns a
23// promise). NestJS awaits pipe results at runtime (pipes-consumer), so the
24// downstream handler still receives the resolved `T` — type-accurate, no
25// behavioral change.
26export class ZodValidationPipe<T = unknown> implements PipeTransform<unknown, Promise<T>> {
27  constructor(private readonly schema: ZodTypeAny) {}
28 
29  async transform(value: unknown, _metadata: ArgumentMetadata): Promise<T> {
30    const result = this.schema.safeParse(value);
31    if (!result.success) {
32      const details = result.error.issues.slice(0, 20).map((i) => ({
33        field: i.path.join("."),
34        issue: i.message
35      }));
36      throw ApiError.validation("Request validation failed.", details);
37    }
38    return result.data as T;
39  }
40}
41 
42/** Convenience factory: `ZodValidate(schema)`. */
43export function ZodValidate(schema: ZodTypeAny): ZodValidationPipe {
44  return new ZodValidationPipe(schema);
45}
46 
47/**
48 * Validate a plain query object (e.g. the result of parsePagination inputs)
49 * against a schema — used by services for non-route validation.
50 */
51export function parseOrThrow<T>(schema: z.ZodType<T>, value: unknown): T {
52  const r = schema.safeParse(value);
53  if (!r.success) {
54    const details = r.error.issues.slice(0, 20).map((i) => ({ field: i.path.join("."), issue: i.message }));
55    throw ApiError.validation("Request validation failed.", details);
56  }
57  return r.data;
58}
59