1 files changed, 24 insertions, 0 deletions
diff --git a/vendor/github.com/vektah/gqlparser/validator/rules/unique_directives_per_location.go b/vendor/github.com/vektah/gqlparser/validator/rules/unique_directives_per_location.go
new file mode 100644
index 00000000..077c4687
--- /dev/null
+++ b/vendor/github.com/vektah/gqlparser/validator/rules/unique_directives_per_location.go
@@ -0,0 +1,24 @@
+package validator
+
+import (
+	"github.com/vektah/gqlparser/ast"
+	. "github.com/vektah/gqlparser/validator"
+)
+
+func init() {
+	AddRule("UniqueDirectivesPerLocation", func(observers *Events, addError AddErrFunc) {
+		observers.OnDirectiveList(func(walker *Walker, directives []*ast.Directive) {
+			seen := map[string]bool{}
+
+			for _, dir := range directives {
+				if seen[dir.Name] {
+					addError(
+						Message(`The directive "%s" can only be used once at this location.`, dir.Name),
+						At(dir.Position),
+					)
+				}
+				seen[dir.Name] = true
+			}
+		})
+	})
+}