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import { inspect } from '../../jsutils/inspect.mjs';
import { GraphQLError } from '../../error/GraphQLError.mjs';
import { getNamedType, isLeafType } from '../../type/definition.mjs';
/**
* Scalar leafs
*
* A GraphQL document is valid only if all leaf fields (fields without
* sub selections) are of scalar or enum types.
*/
export function ScalarLeafsRule(context) {
return {
Field(node) {
const type = context.getType();
const selectionSet = node.selectionSet;
if (type) {
if (isLeafType(getNamedType(type))) {
if (selectionSet) {
const fieldName = node.name.value;
const typeStr = inspect(type);
context.reportError(
new GraphQLError(
`Field "${fieldName}" must not have a selection since type "${typeStr}" has no subfields.`,
{
nodes: selectionSet,
},
),
);
}
} else if (!selectionSet) {
const fieldName = node.name.value;
const typeStr = inspect(type);
context.reportError(
new GraphQLError(
`Field "${fieldName}" of type "${typeStr}" must have a selection of subfields. Did you mean "${fieldName} { ... }"?`,
{
nodes: node,
},
),
);
}
}
},
};
}