Improve typings by providing `mutation`, `query`, `subscription` instead of `graphql`

Currently, HOCs for apollo-react generated using graphql which is quite obvious, but it actually has some flaws described in this issue: https://github.com/apollographql/react-apollo/issues/2568

Long story short, both Mutation and Query function arguments are merged using | so both mutation and data end up in props arguments object.

To provide better typing you can import query, mutation, subscription from react-apollo and use them instead of graphql E.g

import { mutation } from 'react-apollo/mutation-hoc' // import directly, since not exported from root.

export function CreateMessageHOC<TProps, TChildProps = any>(
  operationOptions:
    | ReactApollo.OperationOption<
        TProps,
        CreateMessageMutation,
        CreateMessageVariables,
        CreateMessageProps<TChildProps>
      >
    | undefined,
) {
  return mutation< // mutation here instead of graphql
    TProps,
    CreateMessageMutation,
    CreateMessageVariables,
    CreateMessageProps<TChildProps>
  >(CreateMessageDocument, operationOptions)

This way typings are a little more correct.

Although this is hopefully will be addressed from react-apollo side as well if this will be merged https://github.com/apollographql/react-apollo/pull/2573 It will change signature to withMutation etc. And will be exported from the root, so ReactApollo.withMutation will be possible.

You can fix it right away now, or you can postpone it until PR above is not merged and released.

[RIP21]

@dotansimha @ardatan https://github.com/apollographql/react-apollo/pull/2573 PR mentioned above has been merged. So with* thing will be real very soon.

[dotansimha]

@ardatan I think you can use the codegen core to expose hasQueries, hasMutations and hasSubscriptions here: https://github.com/dotansimha/graphql-code-generator/blob/master/packages/graphql-codegen-core/src/operations/transform-document.ts#L110-L111 and then it will make it easier to know which imports do you actually need.