85 lines
2.8 KiB
JavaScript
85 lines
2.8 KiB
JavaScript
import { GraphQLError } from '../../error/GraphQLError';
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export function cycleErrorMessage(fragName, spreadNames) {
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var via = spreadNames.length ? ' via ' + spreadNames.join(', ') : '';
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return "Cannot spread fragment \"".concat(fragName, "\" within itself").concat(via, ".");
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}
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export function NoFragmentCycles(context) {
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// Tracks already visited fragments to maintain O(N) and to ensure that cycles
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// are not redundantly reported.
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var visitedFrags = Object.create(null); // Array of AST nodes used to produce meaningful errors
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var spreadPath = []; // Position in the spread path
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var spreadPathIndexByName = Object.create(null);
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return {
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OperationDefinition: function OperationDefinition() {
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return false;
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},
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FragmentDefinition: function FragmentDefinition(node) {
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detectCycleRecursive(node);
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return false;
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}
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}; // This does a straight-forward DFS to find cycles.
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// It does not terminate when a cycle was found but continues to explore
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// the graph to find all possible cycles.
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function detectCycleRecursive(fragment) {
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if (visitedFrags[fragment.name.value]) {
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return;
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}
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var fragmentName = fragment.name.value;
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visitedFrags[fragmentName] = true;
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var spreadNodes = context.getFragmentSpreads(fragment.selectionSet);
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if (spreadNodes.length === 0) {
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return;
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}
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spreadPathIndexByName[fragmentName] = spreadPath.length;
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var _iteratorNormalCompletion = true;
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var _didIteratorError = false;
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var _iteratorError = undefined;
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try {
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for (var _iterator = spreadNodes[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
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var spreadNode = _step.value;
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var spreadName = spreadNode.name.value;
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var cycleIndex = spreadPathIndexByName[spreadName];
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spreadPath.push(spreadNode);
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if (cycleIndex === undefined) {
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var spreadFragment = context.getFragment(spreadName);
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if (spreadFragment) {
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detectCycleRecursive(spreadFragment);
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}
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} else {
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var cyclePath = spreadPath.slice(cycleIndex);
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var fragmentNames = cyclePath.slice(0, -1).map(function (s) {
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return s.name.value;
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});
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context.reportError(new GraphQLError(cycleErrorMessage(spreadName, fragmentNames), cyclePath));
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}
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spreadPath.pop();
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}
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} catch (err) {
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_didIteratorError = true;
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_iteratorError = err;
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} finally {
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try {
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if (!_iteratorNormalCompletion && _iterator.return != null) {
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_iterator.return();
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}
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} finally {
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if (_didIteratorError) {
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throw _iteratorError;
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}
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}
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}
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spreadPathIndexByName[fragmentName] = undefined;
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}
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}
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