Initialisation

Added the packages and files for the backend server

node_modules/graphql/validation/rules/PossibleFragmentSpreadsRule.js

@@ -0,0 +1,95 @@
+'use strict';
+
+Object.defineProperty(exports, '__esModule', {
+  value: true,
+});
+exports.PossibleFragmentSpreadsRule = PossibleFragmentSpreadsRule;
+
+var _inspect = require('../../jsutils/inspect.js');
+
+var _GraphQLError = require('../../error/GraphQLError.js');
+
+var _definition = require('../../type/definition.js');
+
+var _typeComparators = require('../../utilities/typeComparators.js');
+
+var _typeFromAST = require('../../utilities/typeFromAST.js');
+
+/**
+ * Possible fragment spread
+ *
+ * A fragment spread is only valid if the type condition could ever possibly
+ * be true: if there is a non-empty intersection of the possible parent types,
+ * and possible types which pass the type condition.
+ */
+function PossibleFragmentSpreadsRule(context) {
+  return {
+    InlineFragment(node) {
+      const fragType = context.getType();
+      const parentType = context.getParentType();
+
+      if (
+        (0, _definition.isCompositeType)(fragType) &&
+        (0, _definition.isCompositeType)(parentType) &&
+        !(0, _typeComparators.doTypesOverlap)(
+          context.getSchema(),
+          fragType,
+          parentType,
+        )
+      ) {
+        const parentTypeStr = (0, _inspect.inspect)(parentType);
+        const fragTypeStr = (0, _inspect.inspect)(fragType);
+        context.reportError(
+          new _GraphQLError.GraphQLError(
+            `Fragment cannot be spread here as objects of type "${parentTypeStr}" can never be of type "${fragTypeStr}".`,
+            {
+              nodes: node,
+            },
+          ),
+        );
+      }
+    },
+
+    FragmentSpread(node) {
+      const fragName = node.name.value;
+      const fragType = getFragmentType(context, fragName);
+      const parentType = context.getParentType();
+
+      if (
+        fragType &&
+        parentType &&
+        !(0, _typeComparators.doTypesOverlap)(
+          context.getSchema(),
+          fragType,
+          parentType,
+        )
+      ) {
+        const parentTypeStr = (0, _inspect.inspect)(parentType);
+        const fragTypeStr = (0, _inspect.inspect)(fragType);
+        context.reportError(
+          new _GraphQLError.GraphQLError(
+            `Fragment "${fragName}" cannot be spread here as objects of type "${parentTypeStr}" can never be of type "${fragTypeStr}".`,
+            {
+              nodes: node,
+            },
+          ),
+        );
+      }
+    },
+  };
+}
+
+function getFragmentType(context, name) {
+  const frag = context.getFragment(name);
+
+  if (frag) {
+    const type = (0, _typeFromAST.typeFromAST)(
+      context.getSchema(),
+      frag.typeCondition,
+    );
+
+    if ((0, _definition.isCompositeType)(type)) {
+      return type;
+    }
+  }
+}