@graphql-mesh/fusion-execution/esm/flattenSelections.js

Runtime for Fusion Supergraph

import { Kind } from 'graphql';
export function flattenSelections(selections, fragments, defer = false) {
    return selections.flatMap(selection => {
        switch (selection.kind) {
            case Kind.FIELD:
                return [
                    {
                        ...selection,
                        selectionSet: selection.selectionSet && {
                            ...selection.selectionSet,
                            selections: flattenSelections(selection.selectionSet.selections, fragments, defer),
                        },
                        defer,
                    },
                ];
            case Kind.INLINE_FRAGMENT:
                if (selection.directives?.some(directive => directive.name.value === 'defer')) {
                    defer = true;
                }
                return flattenSelections(selection.selectionSet.selections, fragments, defer);
            case Kind.FRAGMENT_SPREAD: {
                const fragment = fragments[selection.name.value];
                if (!fragment) {
                    throw new Error(`No fragment found for ${selection.name.value}`);
                }
                if (fragment.directives?.some(directive => directive.name.value === 'defer')) {
                    defer = true;
                }
                return flattenSelections(fragment.selectionSet.selections, fragments, defer);
            }
            default:
                throw new Error(`Unexpected selection node kind ${selection.kind}`);
        }
    });
}