Function JSONStringified

A helper function to parse a JSON string and validate it against a schema.

Use it for built-in schemas like AlbSchema, ApiGatewaySchema, etc. that have some fields that are JSON stringified and extend them with your custom schema.

For example, if you have an event with a JSON stringified body similar to the following:

{
  // ... other fields
  "body": "{\"name\": \"John\", \"age\": 30}",
  "isBase64Encoded": false,
}
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You can extend any built-in schema with your custom schema using the JSONStringified helper function.

import { JSONStringified } from '@aws-lambda-powertools/parser/helpers';
import { AlbSchema } from '@aws-lambda-powertools/parser/schemas/alb';
import { z } from 'zod';

const customSchema = z.object({
  name: z.string(),
  age: z.number(),
});

const extendedSchema = AlbSchema.extend({
  body: JSONStringified(customSchema),
});

type ExtendedAlbEvent = z.infer<typeof extendedSchema>;
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