The resolver's value must be of type object.

[james-tindal]

What is going on here?

Error: "logIn" defined in resolvers, but has invalid value "(parent, { username, password }, context) => context.logIn(username, password)
        .then(userId => LogIn.Success(userId))
        .catch(() => LogIn.Failure)". The resolver's value must be of type object.

[ardatan]

I am not sure :) You need to give more details. A reproduction on CodeSandbox maybe?
Resolvers should be in the following format;

{
  Mutation: {
      logIn: (...) => ...
  }
}

[james-tindal]

Thanks! I figured out what was broken.

[Harshit369]

I also find myself in the same issue. @james-tindal can you share how you fixed it?

[JHerwig]

Some people deserve the hell.

[james-tindal]

I was composing this object from other objects.

{
  Mutation: {
      logIn: (...) => ...
  }
}

Turned out the composed object was not in the proper format.

[Sequoia]

I wish either:

1. an answer with an explanation would be posted here or
2. this question would be deleted so it's purged from google. Currently it's the top result for "The resolver's value must be of type object." and this page doesn't help at all.

Suggestion: delete this q/a page so it is removed from google results.

[james-tindal]

Like the error message says, every top-level value in the resolvers object must be an object. Top-level keys are names of types in the schema.

type SchemaTypeName = string
type SchemaTypeKey = string
type ResolverFunction = (root, args, context, info) => any
type ResolverObject = Record<SchemaTypeKey, ResolverFunction>
type ResolversObject = Record<SchemaTypeName, ResolverObject>

type Query {
  event(id: ID!): Event
}
type Event {
  title: String!
  photoUrl: String!
  related(first: Int, count: Int): [Event]!
}

const resolvers: ResolversObject = {
  Query: {
    event: (root, args, context, info) => {/* ... */}
  },
  Event: {
    title: (root, args, context, info) => {/* ... */},
    photoUrl: (root, args, context, info) => {/* ... */},
    related: (root, args, context, info) => {/* ... */}
  }
}

https://medium.com/paypal-tech/graphql-resolvers-best-practices-cd36fdbcef55

[bdentino]

I'm a little confused by this as well. I think the error message is clear, but I would expect to be able pass a class definition as a resolver (which is type function, not object), seeing as how it's fairly common practice to implement resolvers as a class and return an instance of that class from any point in the graph. I guess you can initialize a dummy instance of the class as described here and pass it through, but it feels like a weird workaround when the this that you're creating will never actually be used.

Is this a reasonable expectation, or am I missing something about the spec or implementation that would make this impractical/discouraged?