Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the bug has not already been reported

Fastify version

4.0.0

Plugin version

5.2.0

Node.js version

19.4

Operating system

macOS

Operating system version (i.e. 20.04, 11.3, 10)

13

Description

Currently, fastify schema validation and the pg: {transact: true} option are not compatible.

The validation schema is executed before the transaction initialization, which is expected behavior. However, when an error response with code FST_ERR_VALIDATION is sent, it triggers the onSend handler of the fastify-postgres hook, which assumes the initialization of a client.

This cause the Cannot read properties of null (reading 'release') error.

Steps to Reproduce

Configure your server:

fastify.post('/strictValidateFail', {
      schema: {
        body: {
          type: 'object',
          properties: {
            hello: { type: 'string' }
          },
          required: ['hello']
        }
      },
      pg: { transact: true }
    }, async (req, reply) => {
      await req.pg.query('THIS QUERY SHOULD NEVER BE EXECUTED WITH WRONG BODY', [])
      return 'never catched'
    });

Send a wrong body post

const response = await fastify.inject({
      url: '/strictValidateFail',
      method: 'POST',
      body: { notValid: 'json input' }
    })

the result is:

{"statusCode":400,"error":"Bad Request","message":"Cannot read properties of null (reading 'release')"}

Expected Behavior

The response should be

{"statusCode":400,"code":"FST_ERR_VALIDATION","error":"Bad Request","message":"body must have required property 'hello'"}