intermittent 500 errors on manual errors thrown

[paul590]

Hello,

I recently started using your library and I am encountering a weird issue. I am using typescript and graphql. Whenever I throw an error in the format of: new Error("This is an error"). The graph ql ui provides the following:

"error": {
"statusCode": 500,
"error": "Internal Server Error",
"message": "Internal Server Error"
}

the strange part happens when i press the run button again on the ui, the proper error message is displayed. This 500 error only appears the first time I try to run a query that throws an error, subsequent calls do not throw this error. I was using Apollo server before and everything worked as expected. Can you please provide some assistance?

Thank you in advance!

[RafaelGSS]

Can you provide a reproduction repository/code?

[paul590]

Hi Rafael, sure thing! I added you to the repo I created https://github.com/paul590/toSendGraphQL

Also, I added a readme where i explain what issues I am seeing. If you would like me to add other developer please let me know. Thank you for your help!

[Eomm]

The link is broken. Is the repo public?

[paul590]

Can you try again please, the repo is private and i added you to it

[Eomm]

It would be better a public repo.

you will see 500 error. On code remove the errorHandler: false it throws correct format on manual error but format changes when system throws error such as when using an incorrect function like test2(code: "test").

Anyway, I think you should define an errorHandler function:

• false would mean you are using the fastify standard error handler
• true you are using the GrapQL standard error handler
• a function would mean you can support both

[paul590]

@Eomm Thank you for your response! I understand I can use this approach, however, is there a reason why when using false we see a 500 error at first and then on the second call the appropriate response? Please let me know. Thank you!

[paul590]

Hi @Eomm I implemented a simple error handler and unfortunately, the 500 error persisted.

this.server.setErrorHandler((error, request, reply) => {
            console.log(error);
            console.log(request);
            console.log(reply);
            reply.send(error);
       })

[RafaelGSS]

Hi @paul590 I'll take a closer look more later, but after a fast investigation, sounds like a bug inside cache of GQL.

[Eomm]

I can't debug it right, now.

The @RafaelGSS 's suggestion could help to spot the issue: you could try to disable the cache to check it rapidly 👍

[paul590]

Hi @RafaelGSS and @Eomm thank you for your help with this. That would make sense as to why we see the second result as intended. What I am failing to understand is why would the first error would be in the format of:

{
"error": {
"statusCode": 500,
"error": "Internal Server Error",
"message": "Internal Server Error"
}
}

if the caching is acting properly shouldnt it be the same error for the second error?

Also, when creating a custom error handler I noticed the object I create is wrapped by an error object. for example { error: { new object variables } } is there a way to remove this error object wrap? Thank you for all your help!

[RafaelGSS]

@paul590 I just changed on fastify-gql/index.js:

- const lru = buildCache(opts)
+ const lru = buildCache({ ...opts, cache: false })

and works fine (the request did not change the result). So, maybe you can define cache at here to you use in your application without transpilation error.

[RafaelGSS]

Btw, is good to create an issue on this plugin to inform the behaviour of the cache.

[paul590]

@RafaelGSS Thank you for letting me know this information. The link that your provided me with didnt seem to show me where I would the cache. would I add this information when initializing the server? If the cache is the issue, is there a way to only remove the cache on errors or would this be a plugin issue? Thank you again!!

server.register(GQL, {
schema,
jit: 1,
path: "/",
graphiql: "playground",
})

[RafaelGSS]

Do you will use:

server.register(GQL, {
  schema,
  jit: 1,
  path: "/",
  graphiql: "playground",
+ cache: false,
})

However, you are using typescript and could have an error because cache property is not defined on the link that I sent. An workaround is:

server.register(GQL, {
  schema,
  jit: 1,
  path: "/",
  graphiql: "playground",
+ cache: false,
+ } as any)

Obs: I do not tried the example above, but should work

[mcollina]

@RafaelGSS can you send a PR to fix the cache issue?