flow like the river

BACK_BACK/node_modules/graphql/validation/rules/UniqueArgumentNamesRule.js

@@ -0,0 +1,37 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.UniqueArgumentNamesRule = UniqueArgumentNamesRule;
+
+var _GraphQLError = require("../../error/GraphQLError.js");
+
+/**
+ * Unique argument names
+ *
+ * A GraphQL field or directive is only valid if all supplied arguments are
+ * uniquely named.
+ */
+function UniqueArgumentNamesRule(context) {
+  var knownArgNames = Object.create(null);
+  return {
+    Field: function Field() {
+      knownArgNames = Object.create(null);
+    },
+    Directive: function Directive() {
+      knownArgNames = Object.create(null);
+    },
+    Argument: function Argument(node) {
+      var argName = node.name.value;
+
+      if (knownArgNames[argName]) {
+        context.reportError(new _GraphQLError.GraphQLError("There can be only one argument named \"".concat(argName, "\"."), [knownArgNames[argName], node.name]));
+      } else {
+        knownArgNames[argName] = node.name;
+      }
+
+      return false;
+    }
+  };
+}