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Schema Validation

Cuple uses Zod for schema validation. It was choosen because of the good defaults and the great type inference. Within Cuple the ZodIssue is also extended for additional type-safety. You can validate, parse, and convert each part of an HTTP request.

Headers validation​

Internally it parses express' req.headers object, so you should use the same naming. Successfully parsed result will be added to data.headers.

builder
  .headersSchema(z.object({ authorization: z.string() }))
  .get(async ({ data }) => {

    data.headers.authorization // this has a string value

  });

Body validation​

Currently only json requests are supported. Successfully parsed result will be added to data.body.

.bodySchema(z.object({
    user: z.object({
        name: z.string().min(3),
        age: z.number()
    })
}))

Query validation​

Note: Query parameters are always strings! Luckily zod can convert it to number if you use z.coerce.number(). Successfully parsed result will be added to data.query.

// For URL query parsing (e.g.: ?somevar=12)
.querySchema(z.object({ somevar: z.coerce.number() }))

Path validation​

Note: Path parameters are always strings! Luckily zod can convert it to number if you use z.coerce.number(). Successfully parsed result will be added to data.body.

// For URL params parsing
.path("/post/:id")
.paramsSchema(z.object({ id: z.coerce.number() }))

On error​

In case of error Cuple sends a ZodValidationError error. An example response:

{
    result: 'validation-error',
    statusCode: 422,
    message: "We found some incorrect field(s) during validating the form.",
    issues: [{
        path: ["email"]
        message: 'This field is required.'
        code: 'invalid_type'
    }]
}