1 files changed, 68 insertions, 0 deletions
diff --git a/vendor/github.com/vektah/gqlparser/validator/rules/possible_fragment_spreads.go b/vendor/github.com/vektah/gqlparser/validator/rules/possible_fragment_spreads.go
new file mode 100644
index 00000000..971decbf
--- /dev/null
+++ b/vendor/github.com/vektah/gqlparser/validator/rules/possible_fragment_spreads.go
@@ -0,0 +1,68 @@
+package validator
+
+import (
+	"github.com/vektah/gqlparser/ast"
+	. "github.com/vektah/gqlparser/validator"
+)
+
+func init() {
+	AddRule("PossibleFragmentSpreads", func(observers *Events, addError AddErrFunc) {
+
+		validate := func(walker *Walker, parentDef *ast.Definition, fragmentName string, emitError func()) {
+			if parentDef == nil {
+				return
+			}
+
+			var parentDefs []*ast.Definition
+			switch parentDef.Kind {
+			case ast.Object:
+				parentDefs = []*ast.Definition{parentDef}
+			case ast.Interface, ast.Union:
+				parentDefs = walker.Schema.GetPossibleTypes(parentDef)
+			default:
+				panic("unexpected type")
+			}
+
+			fragmentDefType := walker.Schema.Types[fragmentName]
+			if fragmentDefType == nil {
+				return
+			}
+			if !fragmentDefType.IsCompositeType() {
+				// checked by FragmentsOnCompositeTypes
+				return
+			}
+			fragmentDefs := walker.Schema.GetPossibleTypes(fragmentDefType)
+
+			for _, fragmentDef := range fragmentDefs {
+				for _, parentDef := range parentDefs {
+					if parentDef.Name == fragmentDef.Name {
+						return
+					}
+				}
+			}
+
+			emitError()
+		}
+
+		observers.OnInlineFragment(func(walker *Walker, inlineFragment *ast.InlineFragment) {
+			validate(walker, inlineFragment.ObjectDefinition, inlineFragment.TypeCondition, func() {
+				addError(
+					Message(`Fragment cannot be spread here as objects of type "%s" can never be of type "%s".`, inlineFragment.ObjectDefinition.Name, inlineFragment.TypeCondition),
+					At(inlineFragment.Position),
+				)
+			})
+		})
+
+		observers.OnFragmentSpread(func(walker *Walker, fragmentSpread *ast.FragmentSpread) {
+			if fragmentSpread.Definition == nil {
+				return
+			}
+			validate(walker, fragmentSpread.ObjectDefinition, fragmentSpread.Definition.TypeCondition, func() {
+				addError(
+					Message(`Fragment "%s" cannot be spread here as objects of type "%s" can never be of type "%s".`, fragmentSpread.Name, fragmentSpread.ObjectDefinition.Name, fragmentSpread.Definition.TypeCondition),
+					At(fragmentSpread.Position),
+				)
+			})
+		})
+	})
+}