graphql_client_codegen: require items referenced from fragments

Fixes: #286

Author: mathstuf

graphql_client_codegen/src/fragments.rs

@@ -56,4 +56,9 @@ impl<'query> GqlFragment<'query> {
     pub(crate) fn is_recursive(&self) -> bool {
         self.selection.contains_fragment(&self.name)
     }
+
+    pub(crate) fn require<'schema>(&self, context: &QueryContext<'query, 'schema>) {
+        self.is_required.set(true);
+        self.selection.require_items(context);
+    }
 }

graphql_client_codegen/src/query.rs

@@ -40,7 +40,7 @@ impl<'query, 'schema> QueryContext<'query, 'schema> {
     /// Mark a fragment as required, so code is actually generated for it.
     pub(crate) fn require_fragment(&self, typename_: &str) {
         if let Some(fragment) = self.fragments.get(typename_) {
-            fragment.is_required.set(true)
+            fragment.require(&self);
         }
     }
 

graphql_client_codegen/src/selection.rs

@@ -167,6 +167,14 @@ impl<'query> Selection<'query> {
     pub(crate) fn len(&self) -> usize {
         self.0.len()
     }
+
+    pub(crate) fn require_items<'s>(&self, context: &crate::query::QueryContext<'query, 's>) {
+        self.0.iter().for_each(|item| {
+            if let SelectionItem::FragmentSpread(SelectionFragmentSpread { fragment_name }) = item {
+                context.require_fragment(fragment_name);
+            }
+        })
+    }
 }
 
 impl<'query> std::convert::From<&'query SelectionSet> for Selection<'query> {