From 7aad6ba78fc19e4b89b0eae12263e79f56eeb97b Mon Sep 17 00:00:00 2001
From: Richard Musiol <mail@richard-musiol.de>
Date: Wed, 31 May 2017 16:25:13 +0200
Subject: [PATCH] refactor: use schema.NamedType

---
 internal/validation/validation.go | 33 +++++++++++++++++++------------
 1 file changed, 20 insertions(+), 13 deletions(-)

diff --git a/internal/validation/validation.go b/internal/validation/validation.go
index ac3cec7161..28c40c6a51 100644
--- a/internal/validation/validation.go
+++ b/internal/validation/validation.go
@@ -87,7 +87,7 @@ func Validate(s *schema.Schema, doc *query.Document) []*errors.QueryError {
 			}
 		}
 
-		var entryPoint common.Type
+		var entryPoint schema.NamedType
 		switch op.Type {
 		case query.Query:
 			entryPoint = s.EntryPoints["query"]
@@ -116,7 +116,7 @@ func Validate(s *schema.Schema, doc *query.Document) []*errors.QueryError {
 		validateName(c, fragNames, frag.Name, "UniqueFragmentNames", "fragment")
 		validateDirectives(opc, "FRAGMENT_DEFINITION", frag.Directives)
 
-		t := resolveType(c, &frag.On)
+		t := unwrapType(resolveType(c, &frag.On))
 		// continue even if t is nil
 		if t != nil && !canBeFragment(t) {
 			c.addErr(frag.On.Loc, "FragmentsOnCompositeTypes", "Fragment %q cannot condition on non composite type %q.", frag.Name.Name, t)
@@ -154,13 +154,13 @@ func Validate(s *schema.Schema, doc *query.Document) []*errors.QueryError {
 	return c.errs
 }
 
-func validateSelectionSet(c *opContext, selSet *query.SelectionSet, t common.Type) {
+func validateSelectionSet(c *opContext, selSet *query.SelectionSet, t schema.NamedType) {
 	for _, sel := range selSet.Selections {
 		validateSelection(c, sel, t)
 	}
 }
 
-func validateSelection(c *opContext, sel query.Selection, t common.Type) {
+func validateSelection(c *opContext, sel query.Selection, t schema.NamedType) {
 	switch sel := sel.(type) {
 	case *query.Field:
 		validateDirectives(c, "FIELD", sel.Directives)
@@ -223,7 +223,7 @@ func validateSelection(c *opContext, sel query.Selection, t common.Type) {
 	case *query.InlineFragment:
 		validateDirectives(c, "INLINE_FRAGMENT", sel.Directives)
 		if sel.On.Name != "" {
-			fragTyp := resolveType(c.context, &sel.On)
+			fragTyp := unwrapType(resolveType(c.context, &sel.On))
 			if fragTyp != nil && !compatible(t, fragTyp) {
 				c.addErr(sel.Loc, "PossibleFragmentSpreads", "Fragment cannot be spread here as objects of type %q can never be of type %q.", t, fragTyp)
 			}
@@ -373,14 +373,21 @@ func fields(t common.Type) schema.FieldList {
 	}
 }
 
-func unwrapType(t common.Type) common.Type {
-	switch t := t.(type) {
-	case *common.List:
-		return unwrapType(t.OfType)
-	case *common.NonNull:
-		return unwrapType(t.OfType)
-	default:
-		return t
+func unwrapType(t common.Type) schema.NamedType {
+	if t == nil {
+		return nil
+	}
+	for {
+		switch t2 := t.(type) {
+		case schema.NamedType:
+			return t2
+		case *common.List:
+			t = t2.OfType
+		case *common.NonNull:
+			t = t2.OfType
+		default:
+			panic("unreachable")
+		}
 	}
 }