Codegen: implement description for custom derives + improve tests

Description attribute was available, but not actually used for derive
Object, InputObject and enum and the fields on input object.

Description is now properly set in each of those cases.

Also, tests for all three derives now properly verify the meta
information (name and description) for the derived GraphQLType.

juniper_codegen/src/derive_enum.rs

@@ -84,6 +84,11 @@ pub fn impl_enum(ast: &syn::DeriveInput) -> Tokens {
     let attrs = EnumAttrs::from_input(ast);
     let name = attrs.name.unwrap_or(ast.ident.to_string());
 
+    let meta_description = match attrs.description {
+        Some(descr) => quote!{ let meta = meta.description(#descr); },
+        None => quote!{ let meta = meta; },
+    };
+
     let mut values = Vec::<Tokens>::new();
     let mut resolves = Vec::<Tokens>::new();
     let mut from_inputs = Vec::<Tokens>::new();
@@ -146,10 +151,11 @@ pub fn impl_enum(ast: &syn::DeriveInput) -> Tokens {
             }
 
             fn meta<'r>(registry: &mut ::juniper::Registry<'r>) -> ::juniper::meta::MetaType<'r> {
-                registry.build_enum_type::<#ident>(&[
+                let meta = registry.build_enum_type::<#ident>(&[
                     #(#values)*
-                ])
-                .into_meta()
+                ]);
+                #meta_description
+                meta.into_meta()
             }
 
             fn resolve(&self, _: Option<&[::juniper::Selection]>, _: &::juniper::Executor<Self::Context>) -> ::juniper::Value {

juniper_codegen/src/derive_input_object.rs

@@ -90,6 +90,11 @@ pub fn impl_input_object(ast: &syn::DeriveInput) -> Tokens {
     let attrs = ObjAttrs::from_input(ast);
     let name = attrs.name.unwrap_or(ast.ident.to_string());
 
+    let meta_description = match attrs.description {
+        Some(descr) => quote!{ let meta = meta.description(#descr); },
+        None => quote!{ let meta = meta; },
+    };
+
     let mut meta_fields = Vec::<Tokens>::new();
     let mut from_inputs = Vec::<Tokens>::new();
     let mut to_inputs = Vec::<Tokens>::new();
@@ -110,9 +115,9 @@ pub fn impl_input_object(ast: &syn::DeriveInput) -> Tokens {
                 ::util::to_camel_case(field_ident.as_ref())
             },
         };
-        let descr = match field_attrs.description {
-            Some(s) => quote!{ Some(#s.to_string())  },
-            None => quote!{ None },
+        let field_description = match field_attrs.description {
+            Some(s) => quote!{ let field = field.description(#s); },
+            None => quote!{ let field = field; },
         };
 
         let default = match field_attrs.default {
@@ -127,18 +132,25 @@ pub fn impl_input_object(ast: &syn::DeriveInput) -> Tokens {
             None => None,
         };
 
-        let meta_field = match default {
+        let create_meta_field = match default {
             Some(ref def) => {
                 quote!{
-                    registry.arg_with_default::<#field_ty>( #name, &#def),
+                    let field = registry.arg_with_default::<#field_ty>( #name, &#def);
                 }
             },
             None => {
                 quote!{
-                    registry.arg::<#field_ty>(#name),
+                    let field = registry.arg::<#field_ty>(#name);
                 }
             }
         };
+        let meta_field = quote!{
+            {
+                #create_meta_field
+                #field_description
+                field
+            },
+        };
         meta_fields.push(meta_field);
 
         // Buil from_input clause.
@@ -183,7 +195,9 @@ pub fn impl_input_object(ast: &syn::DeriveInput) -> Tokens {
                 let fields = &[
                     #(#meta_fields)*
                 ];
-                registry.build_input_object_type::<#ident>(fields).into_meta()
+                let meta = registry.build_input_object_type::<#ident>(fields);
+                #meta_description
+                meta.into_meta()
             }
         }
 

juniper_codegen/src/derive_object.rs

@@ -101,7 +101,6 @@ pub fn impl_object(ast: &syn::DeriveInput) -> Tokens {
         let field_ty = &field.ty;
         let field_attrs = ObjFieldAttrs::from_input(field);
         let field_ident = field.ident.as_ref().unwrap();
-        let field_ident_name = field_ident.to_string();
 
         // Build value.
         let name = match field_attrs.name {

juniper_tests/src/codegen/derive_enum.rs

@@ -24,6 +24,9 @@ fn test_derived_enum() {
   let mut registry = juniper::Registry::new(HashMap::new());
   let meta = SomeEnum::meta(&mut registry);
 
+  assert_eq!(meta.name(), Some("Some"));
+  assert_eq!(meta.description(), Some(&"enum descr".to_string()));
+
   // Test Regular variant.
   assert_eq!(
     SomeEnum::Regular.to(),

juniper_tests/src/codegen/derive_input_object.rs

@@ -1,10 +1,12 @@
-use juniper::{ToInputValue, GraphQLType, FromInputValue};
+use std::collections::HashMap;
+
+use juniper::{self, ToInputValue, GraphQLType, FromInputValue};
 
 #[derive(GraphQLInputObject, Debug, PartialEq)]
-#[graphql(name="MyInput")]
+#[graphql(name="MyInput", description="input descr")]
 struct Input {
   regular_field: String,
-  #[graphql(name="haha", default="33")]
+  #[graphql(name="haha", default="33", description="haha descr")]
   c: i32,
 }
 
@@ -12,6 +14,12 @@ struct Input {
 fn test_derived_input_object() {
   assert_eq!(Input::name(), Some("MyInput"));
 
+  // Validate meta info.
+  let mut registry = juniper::Registry::new(HashMap::new());
+  let meta = Input::meta(&mut registry);
+  assert_eq!(meta.name(), Some("MyInput"));
+  assert_eq!(meta.description(), Some(&"input descr".to_string()));
+
   let obj = Input {
     regular_field: "a".to_string(),
     c: 33,

juniper_tests/src/codegen/derive_object.rs

@@ -1,4 +1,6 @@
-use juniper::{execute, GraphQLType, Value, Variables, EmptyMutation, RootNode};
+use std::collections::HashMap;
+
+use juniper::{self, execute, GraphQLType, Value, Variables, EmptyMutation, RootNode};
 
 #[derive(GraphQLObject, Debug, PartialEq)]
 #[graphql(name="MyObj", description="obj descr")]
@@ -22,6 +24,14 @@ graphql_object!(Query: () |&self| {
 #[test]
 fn test_derived_object() {
   assert_eq!(Obj::name(), Some("MyObj"));
+
+  // Verify meta info.
+  let mut registry = juniper::Registry::new(HashMap::new());
+  let meta = Obj::meta(&mut registry);
+
+  assert_eq!(meta.name(), Some("MyObj"));
+  assert_eq!(meta.description(), Some(&"obj descr".to_string()));
+
   let doc = r#"
         {
             obj {