[Help] fastify.validatorCompiler is null

[giovanni-bertoncelli]

💬 Question here

Is there a way to know exactly when fastify.validatorCompiler is not null and is ready? Since it seems not to be added through the decorate API and I have to use it internally for validation in a not-covered scenario sometimes I get the ajv instance, sometimes null... If there is no way how can I rely on the internal AJV instance of Fastify?

[jsumners]

Without an example to look at, all I can suggest is to explore the new https://www.fastify.io/docs/latest/Server/#schemacontroller option.

[giovanni-bertoncelli]

Mmm I can try to write a snippet:

// myplugin.js
function plugin(fastify, opts, done) {
  fastify.decorate('customValidator', (objectToValidate, schema) => {
     const { validatorCompiler } = fastify;
     // there is no way to know if fastify.validatorCompiler is not null....
     const validator = validatorCompiler({
       schema
     });
    return validator(objectToValidate);
  })
}

[jsumners]

Your plugin would need to be registered after fastify.setValidatorCompiler(aCompiler). I cannot assume you are doing that without a full minimal example. fastify/fastify#2446 is a good example of showing the full context of an issue and keeping it narrow.

[Eomm]

The compilers are ready, after the ready event.

Here there are the tests that cover this behaviour:

https://github.com/fastify/fastify/blob/d1972a6ba6f06bd462f33dfd7a338eed969b51e5/test/schema-feature.test.js#L1074-L1077

This is needed because the ajv instance is built async and when needed and it is not created by default

[giovanni-bertoncelli]

Thank you @Eomm. I figured that out.