Initialisation

Added the packages and files for the backend server

node_modules/graphql/validation/rules/UniqueEnumValueNamesRule.mjs

@@ -0,0 +1,64 @@
+import { GraphQLError } from '../../error/GraphQLError.mjs';
+import { isEnumType } from '../../type/definition.mjs';
+
+/**
+ * Unique enum value names
+ *
+ * A GraphQL enum type is only valid if all its values are uniquely named.
+ */
+export function UniqueEnumValueNamesRule(context) {
+  const schema = context.getSchema();
+  const existingTypeMap = schema ? schema.getTypeMap() : Object.create(null);
+  const knownValueNames = Object.create(null);
+  return {
+    EnumTypeDefinition: checkValueUniqueness,
+    EnumTypeExtension: checkValueUniqueness,
+  };
+
+  function checkValueUniqueness(node) {
+    var _node$values;
+
+    const typeName = node.name.value;
+
+    if (!knownValueNames[typeName]) {
+      knownValueNames[typeName] = Object.create(null);
+    } // FIXME: https://github.com/graphql/graphql-js/issues/2203
+
+    /* c8 ignore next */
+
+    const valueNodes =
+      (_node$values = node.values) !== null && _node$values !== void 0
+        ? _node$values
+        : [];
+    const valueNames = knownValueNames[typeName];
+
+    for (const valueDef of valueNodes) {
+      const valueName = valueDef.name.value;
+      const existingType = existingTypeMap[typeName];
+
+      if (isEnumType(existingType) && existingType.getValue(valueName)) {
+        context.reportError(
+          new GraphQLError(
+            `Enum value "${typeName}.${valueName}" already exists in the schema. It cannot also be defined in this type extension.`,
+            {
+              nodes: valueDef.name,
+            },
+          ),
+        );
+      } else if (valueNames[valueName]) {
+        context.reportError(
+          new GraphQLError(
+            `Enum value "${typeName}.${valueName}" can only be defined once.`,
+            {
+              nodes: [valueNames[valueName], valueDef.name],
+            },
+          ),
+        );
+      } else {
+        valueNames[valueName] = valueDef.name;
+      }
+    }
+
+    return false;
+  }
+}