@graphql-inspector/core/esm/validate/query-depth.js

Tooling for GraphQL. Compare GraphQL Schemas, check documents, find breaking changes, find similar types.

import { GraphQLError, Kind, } from 'graphql';
export function validateQueryDepth({ source, doc, maxDepth, fragmentGraph, }) {
    try {
        calculateDepth({
            node: doc,
            currentDepth: 0,
            maxDepth,
            getFragment(name) {
                return fragmentGraph.getNodeData(name);
            },
        });
    }
    catch (errorOrNode) {
        if (errorOrNode instanceof Error) {
            throw errorOrNode;
        }
        const node = errorOrNode;
        return new GraphQLError(`Query exceeds maximum depth of ${maxDepth}`, node, source, node.loc?.start ? [node.loc.start] : undefined);
    }
}
export function calculateDepth({ node, currentDepth, maxDepth, getFragment, }) {
    if (maxDepth && currentDepth > maxDepth) {
        throw node;
    }
    switch (node.kind) {
        case Kind.FIELD: {
            if (node.name.value.startsWith('__') || !node.selectionSet) {
                return 0;
            }
            const maxInnerDepth = calculateDepth({
                node: node.selectionSet,
                currentDepth: currentDepth + 1,
                maxDepth,
                getFragment,
            });
            return 1 + maxInnerDepth;
        }
        case Kind.SELECTION_SET: {
            return Math.max(...node.selections.map(selection => {
                return calculateDepth({
                    node: selection,
                    currentDepth,
                    maxDepth,
                    getFragment,
                });
            }));
        }
        case Kind.DOCUMENT: {
            return Math.max(...node.definitions.map(def => {
                return calculateDepth({
                    node: def,
                    currentDepth,
                    maxDepth,
                    getFragment,
                });
            }));
        }
        case Kind.OPERATION_DEFINITION:
        case Kind.INLINE_FRAGMENT:
        case Kind.FRAGMENT_DEFINITION: {
            return Math.max(...node.selectionSet.selections.map(selection => {
                return calculateDepth({
                    node: selection,
                    currentDepth,
                    maxDepth,
                    getFragment,
                });
            }));
        }
        case Kind.FRAGMENT_SPREAD:
            return calculateDepth({
                node: getFragment(node.name.value),
                currentDepth,
                maxDepth,
                getFragment,
            });
        default: {
            throw new Error(`Couldn't handle ${node.kind}`);
        }
    }
}
export function countDepth(node, parentDepth, getFragmentReference) {
    let depth = parentDepth;
    if ('selectionSet' in node && node.selectionSet) {
        for (const child of node.selectionSet.selections) {
            depth = Math.max(depth, countDepth(child, parentDepth + 1, getFragmentReference));
        }
    }
    if (node.kind === Kind.FRAGMENT_SPREAD) {
        const fragment = getFragmentReference(node.name.value);
        if (fragment) {
            depth = Math.max(depth, countDepth(fragment, parentDepth + 1, getFragmentReference));
        }
    }
    return depth;
}