Referred doc: http://graphql.org/graphql-js/mutations-and-input-types/
Source: https://github.com/graphql/graphql.github.io/blob/c22ba1a/site/graphql-js/Tutorial-Mutations.md

The result type of createMessage and updateMessage is missing in the schema and the "runnable code" example.
I was expecting the doc to specify the result of mutation types -- a simple boolean that indicates success/fail of the mutation? or just return the newly updated message instance?

Although it may not be the main concern of the article "Mutations and Input Types", but some insights on the design of return type of mutations would be great.