@ardatan/relay-compiler/lib/util/joinArgumentDefinitions.js

A compiler tool for building GraphQL-driven applications.

/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * 
 * @format
 */
// flowlint ambiguous-object-type:error
'use strict';

var _require = require('../core/CompilerError'),
    createUserError = _require.createUserError;

/**
 * Attempts to join the argument definitions for a root fragment
 * and any unmasked fragment spreads reachable from that root fragment,
 * returning a combined list of arguments or throwing if the same
 * variable(s) are used in incompatible ways in different fragments.
 */
function joinArgumentDefinitions(schema, fragment, reachableArguments, directiveName) {
  var joinedArgumentDefinitions = new Map();
  fragment.argumentDefinitions.forEach(function (prevArgDef) {
    joinedArgumentDefinitions.set(prevArgDef.name, prevArgDef);
  });
  reachableArguments.forEach(function (nextArgDef) {
    var prevArgDef = joinedArgumentDefinitions.get(nextArgDef.name);
    var joinedArgDef = prevArgDef == null ? nextArgDef : joinArgumentDefinition(schema, prevArgDef, nextArgDef, directiveName);
    joinedArgumentDefinitions.set(joinedArgDef.name, joinedArgDef);
  });
  return Array.from(joinedArgumentDefinitions.values());
}
/**
 * @private
 *
 * Attempts to join two argument definitions, returning a single argument
 * definition that is compatible with both of the inputs:
 * - If the kind, name, or defaultValue is different then the arguments
 *   cannot be joined, indicated by returning null.
 * - If either of next/prev is a subtype of the other, return the one
 *   that is the subtype: a more narrow type can flow into a more general
 *   type but not the inverse.
 * - Otherwise there is no subtyping relation between prev/next, so return
 *   null to indicate they cannot be joined.
 */


function joinArgumentDefinition(schema, prevArgDef, nextArgDef, directiveName) {
  if (prevArgDef.kind !== nextArgDef.kind) {
    throw createUserError('Cannot combine global and local variables when applying ' + "".concat(directiveName, "."), [prevArgDef.loc, nextArgDef.loc]);
  } else if (prevArgDef.kind === 'LocalArgumentDefinition' && nextArgDef.kind === 'LocalArgumentDefinition' && prevArgDef.defaultValue !== nextArgDef.defaultValue) {
    throw createUserError('Cannot combine local variables with different defaultValues when ' + "applying ".concat(directiveName, "."), [prevArgDef.loc, nextArgDef.loc]);
  } else if (schema.isTypeSubTypeOf(nextArgDef.type, prevArgDef.type)) {
    // prevArgDef is less strict than nextArgDef
    return nextArgDef;
  } else if (schema.isTypeSubTypeOf(prevArgDef.type, nextArgDef.type)) {
    return prevArgDef;
  } else {
    var prevArgType = prevArgDef.type != null ? schema.getTypeString(prevArgDef.type) : 'unknown';
    var nextArgType = nextArgDef.type != null ? schema.getTypeString(nextArgDef.type) : 'unknown';
    throw createUserError('Cannot combine variables with incompatible types ' + "".concat(prevArgType, " and ").concat(nextArgType, " ") + "when applying ".concat(directiveName, "."), [prevArgDef.loc, nextArgDef.loc]);
  }
}

module.exports = joinArgumentDefinitions;