| import { GraphQLError } from '../../error/GraphQLError.mjs'; |
| |
| /** |
| * No unused variables |
| * |
| * A GraphQL operation is only valid if all variables defined by an operation |
| * are used, either directly or within a spread fragment. |
| * |
| * See https://spec.graphql.org/draft/#sec-All-Variables-Used |
| */ |
| export function NoUnusedVariablesRule(context) { |
| let variableDefs = []; |
| return { |
| OperationDefinition: { |
| enter() { |
| variableDefs = []; |
| }, |
| |
| leave(operation) { |
| const variableNameUsed = Object.create(null); |
| const usages = context.getRecursiveVariableUsages(operation); |
| |
| for (const { node } of usages) { |
| variableNameUsed[node.name.value] = true; |
| } |
| |
| for (const variableDef of variableDefs) { |
| const variableName = variableDef.variable.name.value; |
| |
| if (variableNameUsed[variableName] !== true) { |
| context.reportError( |
| new GraphQLError( |
| operation.name |
| ? `Variable "$${variableName}" is never used in operation "${operation.name.value}".` |
| : `Variable "$${variableName}" is never used.`, |
| { |
| nodes: variableDef, |
| }, |
| ), |
| ); |
| } |
| } |
| }, |
| }, |
| |
| VariableDefinition(def) { |
| variableDefs.push(def); |
| }, |
| }; |
| } |