Help on using Mutation in Additional Resolver

[neerajkr666]

Need help in making use of a mutation from an underlying open API schema

Scenario:
Have setup with multiple sources and from one of the underlying source (openapi) need to fetch data and set to a new field. Need to use additional resolvers code since the input object for this mutation requires building an complex input object.
This fetch needs to be from a mutation since the underlying schema has this as POST api.
I found documentation/example where I can use Query but could not find anything on Mutation.

I saw how context.sourceName.Query.fieldName can be used for queries and tried out context.sourceName.Mutation.fieldName which did not work. I tried to directly call fetch method and it worked.

Isn't it possible to call Mutation? Or is there any other way?

Thanks in Advance.

Part of .meshrc.yaml:

sources:
-name: Source1
    handler:
      openapi:
        baseUrl:<baseUrl>
        source: .<schema>
additionalTypeDefs: |
  extend type ExistingType{
    newField: NewType1
  }
  type NewType1 {
    subField1: [Type2]
  }


additionalResolvers:
  - ./additionalResolvers/additionalResolvers.js

Additional Resolver Code, which did not work:

resolvers = {
 NewType1: {
        subField1: {
            resolve: async(root, args, context, info) => {
                return fetchsubField1(context, root,info)
            }
        }
}
async function fetchSubField1(context, root, info) {
    let value1 = 100
    let value 2 =200

    const result =  await context.api
        .Mutation.postApi({
            root,
            context,
            info,
            args: {
                subFieldFetchRequest: { queryField1: value1, queryField2: value2 }
            },
        });
    const responseJson = await result.json()
    return responseJson 
}

The fetch call which worked:

async function fetchSubField1(context, root) {
    let value1 = 100
    let value 2 =200
    var query = mutation PostApi($subFieldFetchRequest: SubFieldFetchRequest!) {
        postApi(subFieldFetchRequest: $subFieldFetchRequest) {
            result{
                responseField1
                responseField1
            }
         }
    };

    const result = await fetch('http://localhost:4000/graphql', {
        method: 'POST',
        headers: reqHeaders,
        body: JSON.stringify({
            query,
            variables: {
                subFieldFetchRequest: { queryField1: value1, queryField2: value2 }
            }
        })
    })
    const responseJson  = await result .json();
    return responseJson 

[ardatan]

I think you saw a wrong example, it is actually SourceName.TypeName.FieldName. There is no api;
https://github.com/Urigo/graphql-mesh/blob/master/examples/json-schema-covid/src/additionalResolvers.ts#L6

[neerajkr666]

the term api was used for the fieldName. I will re-word the question.
The issue is SourceName.TypeName.FieldName is correctly working in case of Query but not for Mutation. It's returning as null.

[neerajkr666]

Can anyone please help on this? How to use mutation for fetching