Add basic enum introspection tests

Contrived for now - will need to expand on the graphql_enum! macro to
include descriptions and deprecations

src/executor_tests/introspection.rs

@@ -0,0 +1,70 @@
+use std::collections::HashMap;
+
+use executor::FieldResult;
+use value::Value;
+use schema::model::RootNode;
+
+enum Sample {
+    One,
+    Two,
+}
+
+struct Root {}
+
+graphql_enum!(Sample as "SampleEnum" {
+    Sample::One => "ONE",
+    Sample::Two => "TWO",
+});
+
+graphql_object!(Root: () as "Root" |&self| {
+    field sample_enum() -> FieldResult<Sample> {
+        Ok(Sample::One)
+    }
+});
+
+#[test]
+fn enum_introspection() {
+    let doc = r#"
+    {
+        __type(name: "SampleEnum") {
+            enumValues {
+                name
+                description
+                isDeprecated
+                deprecationReason
+            }
+        }
+    }
+    "#;
+    let schema = RootNode::new(Root {}, ());
+
+    let (result, errs) = ::execute(doc, None, &schema, &HashMap::new(), &())
+        .expect("Execution failed");
+
+    assert_eq!(errs, []);
+
+    println!("Result: {:?}", result);
+
+    let values = result
+        .as_object_value().expect("Result is not an object")
+        .get("__type").expect("__type field missing")
+        .as_object_value().expect("__type field not an object value")
+        .get("enumValues").expect("enumValues field missing")
+        .as_list_value().expect("enumValues not a list");
+
+    assert_eq!(values.len(), 2);
+
+    assert!(values.contains(&Value::object(vec![
+        ("name", Value::string("ONE")),
+        ("description", Value::null()),
+        ("isDeprecated", Value::boolean(false)),
+        ("deprecationReason", Value::null()),
+    ].into_iter().collect())));
+
+    assert!(values.contains(&Value::object(vec![
+        ("name", Value::string("TWO")),
+        ("description", Value::null()),
+        ("isDeprecated", Value::boolean(false)),
+        ("deprecationReason", Value::null()),
+    ].into_iter().collect())));
+}

src/executor_tests/mod.rs

@@ -0,0 +1 @@
+mod introspection;

src/lib.rs

@@ -189,6 +189,8 @@ mod integrations;
 #[cfg(all(test, not(feature="expose-test-schema")))] mod tests;
 #[cfg(feature="expose-test-schema")] pub mod tests;
 
+#[cfg(test)] mod executor_tests;
+
 use std::collections::HashMap;
 
 use rustc_serialize::json::{ToJson, Json};