| "use strict"; |
| |
| Object.defineProperty(exports, "__esModule", { |
| value: true |
| }); |
| exports.NoFragmentCyclesRule = NoFragmentCyclesRule; |
| |
| var _GraphQLError = require("../../error/GraphQLError"); |
| |
| function NoFragmentCyclesRule(context) { |
| // Tracks already visited fragments to maintain O(N) and to ensure that cycles |
| // are not redundantly reported. |
| var visitedFrags = Object.create(null); // Array of AST nodes used to produce meaningful errors |
| |
| var spreadPath = []; // Position in the spread path |
| |
| var spreadPathIndexByName = Object.create(null); |
| return { |
| OperationDefinition: function OperationDefinition() { |
| return false; |
| }, |
| FragmentDefinition: function FragmentDefinition(node) { |
| detectCycleRecursive(node); |
| return false; |
| } |
| }; // This does a straight-forward DFS to find cycles. |
| // It does not terminate when a cycle was found but continues to explore |
| // the graph to find all possible cycles. |
| |
| function detectCycleRecursive(fragment) { |
| if (visitedFrags[fragment.name.value]) { |
| return; |
| } |
| |
| var fragmentName = fragment.name.value; |
| visitedFrags[fragmentName] = true; |
| var spreadNodes = context.getFragmentSpreads(fragment.selectionSet); |
| |
| if (spreadNodes.length === 0) { |
| return; |
| } |
| |
| spreadPathIndexByName[fragmentName] = spreadPath.length; |
| |
| for (var _i2 = 0; _i2 < spreadNodes.length; _i2++) { |
| var spreadNode = spreadNodes[_i2]; |
| var spreadName = spreadNode.name.value; |
| var cycleIndex = spreadPathIndexByName[spreadName]; |
| spreadPath.push(spreadNode); |
| |
| if (cycleIndex === undefined) { |
| var spreadFragment = context.getFragment(spreadName); |
| |
| if (spreadFragment) { |
| detectCycleRecursive(spreadFragment); |
| } |
| } else { |
| var cyclePath = spreadPath.slice(cycleIndex); |
| var viaPath = cyclePath.slice(0, -1).map(function (s) { |
| return '"' + s.name.value + '"'; |
| }).join(', '); |
| context.reportError(new _GraphQLError.GraphQLError("Cannot spread fragment \"".concat(spreadName, "\" within itself") + (viaPath !== '' ? " via ".concat(viaPath, ".") : '.'), cyclePath)); |
| } |
| |
| spreadPath.pop(); |
| } |
| |
| spreadPathIndexByName[fragmentName] = undefined; |
| } |
| } |