| /** @category Validation Rules */ |
| import { GraphQLError } from '../../error/GraphQLError.mjs'; |
| |
| /** |
| * No unused fragments |
| * |
| * A GraphQL document is only valid if all fragment definitions are spread |
| * within operations, or spread within other fragments spread within operations. |
| * |
| * See https://spec.graphql.org/draft/#sec-Fragments-Must-Be-Used |
| * @param context - The validation context used while checking the document. |
| * @returns A visitor that reports validation errors for this rule. |
| * @example |
| * ```ts |
| * import { buildSchema, parse, validate } from 'graphql'; |
| * import { NoUnusedFragmentsRule } from 'graphql/validation'; |
| * |
| * const schema = buildSchema(` |
| * type Query { |
| * name: String |
| * } |
| * `); |
| * |
| * const invalidDocument = parse(` |
| * fragment Unused on Query { name } query { name } |
| * `); |
| * const invalidErrors = validate(schema, invalidDocument, [NoUnusedFragmentsRule]); |
| * |
| * invalidErrors.length; // => 1 |
| * |
| * const validDocument = parse(` |
| * fragment Used on Query { name } query { ...Used } |
| * `); |
| * const validErrors = validate(schema, validDocument, [NoUnusedFragmentsRule]); |
| * |
| * validErrors; // => [] |
| * ``` |
| */ |
| export function NoUnusedFragmentsRule(context) { |
| const operationDefs = []; |
| const fragmentDefs = []; |
| return { |
| OperationDefinition(node) { |
| operationDefs.push(node); |
| return false; |
| }, |
| |
| FragmentDefinition(node) { |
| fragmentDefs.push(node); |
| return false; |
| }, |
| |
| Document: { |
| leave() { |
| const fragmentNameUsed = Object.create(null); |
| |
| for (const operation of operationDefs) { |
| for (const fragment of context.getRecursivelyReferencedFragments( |
| operation, |
| )) { |
| fragmentNameUsed[fragment.name.value] = true; |
| } |
| } |
| |
| for (const fragmentDef of fragmentDefs) { |
| const fragName = fragmentDef.name.value; |
| |
| if (fragmentNameUsed[fragName] !== true) { |
| context.reportError( |
| new GraphQLError(`Fragment "${fragName}" is never used.`, { |
| nodes: fragmentDef, |
| }), |
| ); |
| } |
| } |
| }, |
| }, |
| }; |
| } |