The build object contains a number of helpers and sources of information relevant to the current build of the GraphQL API. If you're in watch mode then every time a new schema is generated a new build object will be used.

The following properties/methods are available on the initial build object (more may be added by plugins via the build hook):

newWithHooks(type, spec, scope)

The bread-and-butter of Graphile Engine, this method is how we build hooked GraphQL objects:

const MyType = newWithHooks(type, spec, scope);

• type is a GraphQL object type, such as GraphQLEnumType or GraphQLInputObjectType
• spec is a valid specification that will be passed through the relevant hooks before ultimately being passed to the constructor of the aforementioned type and returning an instance of that type
• scope is where you can add scope information that will be available through the scope property in the context object passed to hooks (see Context below)

extend(input, extensions)

Returns a new object by merging the properties of input and extensions without overwriting. If any clashes occur an error will be throw. It is advisable to use this instead of Object.assign or {...input, ...extensions} because it will warn you if you're accidentally overwriting something.

graphql

Equivalent to require('graphql'), by using this property you don't have to import graphql and you're less likely to get version conflicts which are hard to diagnose and resolve. Use of this property over importing graphql yourself is highly recommended.

getTypeByName(typeName)

Returns the GraphQL type associated with the given name, if it is known to the current build, or null otherwise. Objects built with newWithHooks are automatically registered, but external objects must be registered via:

addType(type: GraphQLNamedType)

Registers an external (un-hooked) GraphQL type with the system so that it may be referenced via getTypeByName()

getAliasFromResolveInfo(resolveInfo)

Use this in your resolver to quickly retrieve the alias that this field was requested as.

From graphql-parse-resolve-info

resolveAlias

Can be used in place of the resolve method for a field if you wish it to resolve to the alias the field was requested as (as opposed to its name).

resolveAlias(data, _args, _context, resolveInfo) {
  const alias = getAliasFromResolveInfo(resolveInfo);
  return data[alias];
}