Serverless-offline: implement Request validation

[dnalborczyk]

serverless: https://github.com/serverless/serverless/pull/5956

https://serverless.com/framework/docs/providers/aws/events/apigateway/#request-schema-validation

https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-request-validation-set-up.html

former PR, could maybe re-use tests: https://github.com/dherault/serverless-offline/pull/589

[alefpereira]

Dears, other day I implemented a poc using Ajv for an API middleware. I'll try to work on that this weekend.

It is something like this:

const Ajv = require('ajv');
const ajv = new Ajv({$data: true});

// Actually, load all scheme first and put them in a object.
// schemeFile = loaded from yml:function:events:http:requests:schema:
const testSchema = ajv.compile(schemeFile);

Validation could be something like this:

// Content-Type: application/json
const parsedBody = JSON.parse(event.body)
const valid = testSchema(parsedBody);
  if (valid){
    // call function
  }else {
    return {
      statusCode: 422,
      body: JSON.stringify(errorTemplate)
  };}

[rohit-sourcefuse]

Any update on this feature guys?

[ItayElgazar]

Bump