GraphQL Mutation how to make fields optional to update fields only by selection and generate schema

Question

I have a graphql mutation defined as follows

type Mutation {
    updateParts(
      partId: String!
      parts: PartRequest!
    ): UpdatePartsResponse!
}

input PartRequest {
    name: String!
    image: Strings!
    boltTypes: [Bolts]!
}

input Bolts {
    code: String!
    metadata: String!
}

Mhy requirement was to update fields upon selection as following.

• update all

mutation {
  updateParts(
    partId: "0x1223"
    parts: {
      name: "some"
      image: "dark.png"
      boltTypes: [
        { code: "A", metadata: "B" }
      ]
    }
  ) 
  }
}

• Update by selection: name only

mutation {
  updateParts(
    partId: "0x1223"
    parts: {
      name: "some"
    }
  ) 
  }
}

• Update by selection: parts only

mutation {
  updateParts(
    partId: "0x1223"
    parts: {
      boltTypes: [
        { code: "A", metadata: "B" }
      ]
    }
  ) 
  }
}

How to construct a schema to achieve this ?

Answer 1

You have to make your arguments optional to achieve this. Try the following schema:

type Mutation {
    updateParts(
        partId: String!
        parts: PartRequest!
    ): UpdatePartsResponse!
}

input PartRequest {
    name: String
    image: String
    boltTypes: [Bolts!]
}

input Bolts {
    code: String!
    metadata: String!
}

Notice the PartRequest input object. The fields are nullable. That means you don't necessarily need to provide a value for those arguments. The ! means they are NON_NULL types, which means you have to provide a value for those always.

I have made the boltTypes field type to [Bolts!] which means the boltTypes field can be null, but the array cannot have null as an element.