typename doesn't work on basic types.

[csilvers]

It seems like the typename directive only works on structs. But it would be great if it worked on basic types like string, so you could do:

query x {
    # @genqlient(typename: "RenderType")
    renderType
}

where renderType is a string in the graphql schema, and the generated code would be:

type RenderType string
struct x {
    renderType RenderType
}

[csilvers]

I tried to implement this by modifying convertDefinition, but I don't think that will work: that function assumes that there's a 1-to-1 mapping from Go types to Graphql types, and that isn't necessarily true in this case. So maybe this is more a feature request than a bug.

I think the real issue is that directives apply not only to a node but also its children. So if you have:

  # @genqlient(typename: "User")
  users { id name }

then it tries to apply the typename: "User" to id and name as well.

I don't understand how this doesn't cause problems elsewhere, like if you had:

  # @genqlient(typename: "User")
  users { id name { first last } }

wouldn't it cause the type for name { first last } to be User as well? But it definitely causes problems for this!

[csilvers]

OK, I think it is a bug in genqlient. WIll file separately.

[csilvers]

I think this can't be implemented until #131 is resolved. But once it is, this diff might be sufficient:

--- a/generate/convert.go
+++ b/generate/convert.go
@@ -289,7 +289,7 @@ func (g *generator) convertDefinition(
                }, err
        }
        goBuiltinName, ok := builtinTypes[def.Name]
-       if ok {
+       if ok && options.TypeName == "" {
                return &goOpaqueType{GoRef: goBuiltinName, GraphQLName: def.Name
}, nil
        }
 
@@ -479,6 +479,12 @@ func (g *generator) convertDefinition(
                return g.addType(goType, goType.GoName, pos)
 
        case ast.Scalar:
+               if builtinTypes[def.Name] != "" {
+                       // In this case, the user asked for a custom Go type-nam
e
+                       // for a built-in type, e.g. `typename MyString string`.
+                       return &goOpaqueType{GoRef: name, GraphQLName: def.Name}
, nil
+               }
+

(plus changing the tests to test for it: I changed it liks this:

--- a/generate/testdata/queries/TypeNames.graphql
+++ b/generate/testdata/queries/TypeNames.graphql
@@ -3,7 +3,11 @@ query TypeNames {
   # @genqlient(typename: "User")
   user { id name }
   # @genqlient(typename: "Item")
-  randomItem { id name }
+  randomItem {
+     id
+     # @genqlient(typename: "NameType")
+     name
+  }
   # (ok to reuse the name as long as they match)
   # @genqlient(typename: "User")
   users { id name }

)