graphql/utilities/extendSchema.mjs

function ownKeys(object, enumerableOnly) { var keys = Object.keys(object); if (Object.getOwnPropertySymbols) { var symbols = Object.getOwnPropertySymbols(object); if (enumerableOnly) symbols = symbols.filter(function (sym) { return Object.getOwnPropertyDescriptor(object, sym).enumerable; }); keys.push.apply(keys, symbols); } return keys; }

function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; if (i % 2) { ownKeys(source, true).forEach(function (key) { _defineProperty(target, key, source[key]); }); } else if (Object.getOwnPropertyDescriptors) { Object.defineProperties(target, Object.getOwnPropertyDescriptors(source)); } else { ownKeys(source).forEach(function (key) { Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key)); }); } } return target; }

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import flatMap from '../polyfills/flatMap';
import objectValues from '../polyfills/objectValues';
import inspect from '../jsutils/inspect';
import mapValue from '../jsutils/mapValue';
import invariant from '../jsutils/invariant';
import devAssert from '../jsutils/devAssert';
import keyValMap from '../jsutils/keyValMap';
import { Kind } from '../language/kinds';
import { isTypeDefinitionNode, isTypeExtensionNode } from '../language/predicates';
import { assertValidSDLExtension } from '../validation/validate';
import { GraphQLDirective } from '../type/directives';
import { isSpecifiedScalarType } from '../type/scalars';
import { isIntrospectionType } from '../type/introspection';
import { assertSchema, GraphQLSchema } from '../type/schema';
import { isScalarType, isObjectType, isInterfaceType, isUnionType, isListType, isNonNullType, isEnumType, isInputObjectType, GraphQLList, GraphQLNonNull, GraphQLScalarType, GraphQLObjectType, GraphQLInterfaceType, GraphQLUnionType, GraphQLEnumType, GraphQLInputObjectType } from '../type/definition';
import { ASTDefinitionBuilder } from './buildASTSchema';

/**
 * Produces a new schema given an existing schema and a document which may
 * contain GraphQL type extensions and definitions. The original schema will
 * remain unaltered.
 *
 * Because a schema represents a graph of references, a schema cannot be
 * extended without effectively making an entire copy. We do not know until it's
 * too late if subgraphs remain unchanged.
 *
 * This algorithm copies the provided schema, applying extensions while
 * producing the copy. The original schema remains unaltered.
 *
 * Accepts options as a third argument:
 *
 *    - commentDescriptions:
 *        Provide true to use preceding comments as the description.
 *
 */
export function extendSchema(schema, documentAST, options) {
  assertSchema(schema);
  documentAST && documentAST.kind === Kind.DOCUMENT || devAssert(0, 'Must provide valid Document AST');

  if (!options || !(options.assumeValid || options.assumeValidSDL)) {
    assertValidSDLExtension(documentAST, schema);
  } // Collect the type definitions and extensions found in the document.


  var typeDefs = [];
  var typeExtsMap = Object.create(null); // New directives and types are separate because a directives and types can
  // have the same name. For example, a type named "skip".

  var directiveDefs = [];
  var schemaDef; // Schema extensions are collected which may add additional operation types.

  var schemaExts = [];

  for (var _i2 = 0, _documentAST$definiti2 = documentAST.definitions; _i2 < _documentAST$definiti2.length; _i2++) {
    var def = _documentAST$definiti2[_i2];

    if (def.kind === Kind.SCHEMA_DEFINITION) {
      schemaDef = def;
    } else if (def.kind === Kind.SCHEMA_EXTENSION) {
      schemaExts.push(def);
    } else if (isTypeDefinitionNode(def)) {
      typeDefs.push(def);
    } else if (isTypeExtensionNode(def)) {
      var extendedTypeName = def.name.value;
      var existingTypeExts = typeExtsMap[extendedTypeName];
      typeExtsMap[extendedTypeName] = existingTypeExts ? existingTypeExts.concat([def]) : [def];
    } else if (def.kind === Kind.DIRECTIVE_DEFINITION) {
      directiveDefs.push(def);
    }
  } // If this document contains no new types, extensions, or directives then
  // return the same unmodified GraphQLSchema instance.


  if (Object.keys(typeExtsMap).length === 0 && typeDefs.length === 0 && directiveDefs.length === 0 && schemaExts.length === 0 && !schemaDef) {
    return schema;
  }

  var schemaConfig = schema.toConfig();
  var astBuilder = new ASTDefinitionBuilder(options, function (typeName) {
    var type = typeMap[typeName];

    if (type === undefined) {
      throw new Error("Unknown type: \"".concat(typeName, "\"."));
    }

    return type;
  });
  var typeMap = keyValMap(typeDefs, function (node) {
    return node.name.value;
  }, function (node) {
    return astBuilder.buildType(node);
  });

  for (var _i4 = 0, _schemaConfig$types2 = schemaConfig.types; _i4 < _schemaConfig$types2.length; _i4++) {
    var existingType = _schemaConfig$types2[_i4];
    typeMap[existingType.name] = extendNamedType(existingType);
  } // Get the extended root operation types.


  var operationTypes = {
    query: schemaConfig.query && schemaConfig.query.name,
    mutation: schemaConfig.mutation && schemaConfig.mutation.name,
    subscription: schemaConfig.subscription && schemaConfig.subscription.name
  };

  if (schemaDef) {
    for (var _i6 = 0, _schemaDef$operationT2 = schemaDef.operationTypes; _i6 < _schemaDef$operationT2.length; _i6++) {
      var _ref2 = _schemaDef$operationT2[_i6];
      var operation = _ref2.operation;
      var type = _ref2.type;
      operationTypes[operation] = type.name.value;
    }
  } // Then, incorporate schema definition and all schema extensions.


  for (var _i8 = 0; _i8 < schemaExts.length; _i8++) {
    var schemaExt = schemaExts[_i8];

    if (schemaExt.operationTypes) {
      for (var _i10 = 0, _schemaExt$operationT2 = schemaExt.operationTypes; _i10 < _schemaExt$operationT2.length; _i10++) {
        var _ref4 = _schemaExt$operationT2[_i10];
        var _operation = _ref4.operation;
        var _type = _ref4.type;
        operationTypes[_operation] = _type.name.value;
      }
    }
  } // Support both original legacy names and extended legacy names.


  var allowedLegacyNames = schemaConfig.allowedLegacyNames.concat(options && options.allowedLegacyNames || []); // Then produce and return a Schema with these types.

  return new GraphQLSchema({
    // Note: While this could make early assertions to get the correctly
    // typed values, that would throw immediately while type system
    // validation with validateSchema() will produce more actionable results.
    query: getMaybeTypeByName(operationTypes.query),
    mutation: getMaybeTypeByName(operationTypes.mutation),
    subscription: getMaybeTypeByName(operationTypes.subscription),
    types: objectValues(typeMap),
    directives: getMergedDirectives(),
    astNode: schemaDef || schemaConfig.astNode,
    extensionASTNodes: schemaConfig.extensionASTNodes.concat(schemaExts),
    allowedLegacyNames: allowedLegacyNames
  }); // Below are functions used for producing this schema that have closed over
  // this scope and have access to the schema, cache, and newly defined types.

  function replaceType(type) {
    if (isListType(type)) {
      return new GraphQLList(replaceType(type.ofType));
    } else if (isNonNullType(type)) {
      return new GraphQLNonNull(replaceType(type.ofType));
    }

    return replaceNamedType(type);
  }

  function replaceNamedType(type) {
    return typeMap[type.name];
  }

  function getMaybeTypeByName(typeName) {
    return typeName ? typeMap[typeName] : null;
  }

  function getMergedDirectives() {
    var existingDirectives = schema.getDirectives().map(extendDirective);
    existingDirectives || devAssert(0, 'schema must have default directives');
    return existingDirectives.concat(directiveDefs.map(function (node) {
      return astBuilder.buildDirective(node);
    }));
  }

  function extendNamedType(type) {
    if (isIntrospectionType(type) || isSpecifiedScalarType(type)) {
      // Builtin types are not extended.
      return type;
    } else if (isScalarType(type)) {
      return extendScalarType(type);
    } else if (isObjectType(type)) {
      return extendObjectType(type);
    } else if (isInterfaceType(type)) {
      return extendInterfaceType(type);
    } else if (isUnionType(type)) {
      return extendUnionType(type);
    } else if (isEnumType(type)) {
      return extendEnumType(type);
    } else if (isInputObjectType(type)) {
      return extendInputObjectType(type);
    } // Not reachable. All possible types have been considered.


    /* istanbul ignore next */
    invariant(false, 'Unexpected type: ' + inspect(type));
  }

  function extendDirective(directive) {
    var config = directive.toConfig();
    return new GraphQLDirective(_objectSpread({}, config, {
      args: mapValue(config.args, extendArg)
    }));
  }

  function extendInputObjectType(type) {
    var config = type.toConfig();
    var extensions = typeExtsMap[config.name] || [];
    var fieldNodes = flatMap(extensions, function (node) {
      return node.fields || [];
    });
    return new GraphQLInputObjectType(_objectSpread({}, config, {
      fields: function fields() {
        return _objectSpread({}, mapValue(config.fields, function (field) {
          return _objectSpread({}, field, {
            type: replaceType(field.type)
          });
        }), {}, keyValMap(fieldNodes, function (field) {
          return field.name.value;
        }, function (field) {
          return astBuilder.buildInputField(field);
        }));
      },
      extensionASTNodes: config.extensionASTNodes.concat(extensions)
    }));
  }

  function extendEnumType(type) {
    var config = type.toConfig();
    var extensions = typeExtsMap[type.name] || [];
    var valueNodes = flatMap(extensions, function (node) {
      return node.values || [];
    });
    return new GraphQLEnumType(_objectSpread({}, config, {
      values: _objectSpread({}, config.values, {}, keyValMap(valueNodes, function (value) {
        return value.name.value;
      }, function (value) {
        return astBuilder.buildEnumValue(value);
      })),
      extensionASTNodes: config.extensionASTNodes.concat(extensions)
    }));
  }

  function extendScalarType(type) {
    var config = type.toConfig();
    var extensions = typeExtsMap[config.name] || [];
    return new GraphQLScalarType(_objectSpread({}, config, {
      extensionASTNodes: config.extensionASTNodes.concat(extensions)
    }));
  }

  function extendObjectType(type) {
    var config = type.toConfig();
    var extensions = typeExtsMap[config.name] || [];
    var interfaceNodes = flatMap(extensions, function (node) {
      return node.interfaces || [];
    });
    var fieldNodes = flatMap(extensions, function (node) {
      return node.fields || [];
    });
    return new GraphQLObjectType(_objectSpread({}, config, {
      interfaces: function interfaces() {
        return [].concat(type.getInterfaces().map(replaceNamedType), interfaceNodes.map(function (node) {
          return astBuilder.getNamedType(node);
        }));
      },
      fields: function fields() {
        return _objectSpread({}, mapValue(config.fields, extendField), {}, keyValMap(fieldNodes, function (node) {
          return node.name.value;
        }, function (node) {
          return astBuilder.buildField(node);
        }));
      },
      extensionASTNodes: config.extensionASTNodes.concat(extensions)
    }));
  }

  function extendInterfaceType(type) {
    var config = type.toConfig();
    var extensions = typeExtsMap[config.name] || [];
    var fieldNodes = flatMap(extensions, function (node) {
      return node.fields || [];
    });
    return new GraphQLInterfaceType(_objectSpread({}, config, {
      fields: function fields() {
        return _objectSpread({}, mapValue(config.fields, extendField), {}, keyValMap(fieldNodes, function (node) {
          return node.name.value;
        }, function (node) {
          return astBuilder.buildField(node);
        }));
      },
      extensionASTNodes: config.extensionASTNodes.concat(extensions)
    }));
  }

  function extendUnionType(type) {
    var config = type.toConfig();
    var extensions = typeExtsMap[config.name] || [];
    var typeNodes = flatMap(extensions, function (node) {
      return node.types || [];
    });
    return new GraphQLUnionType(_objectSpread({}, config, {
      types: function types() {
        return [].concat(type.getTypes().map(replaceNamedType), typeNodes.map(function (node) {
          return astBuilder.getNamedType(node);
        }));
      },
      extensionASTNodes: config.extensionASTNodes.concat(extensions)
    }));
  }

  function extendField(field) {
    return _objectSpread({}, field, {
      type: replaceType(field.type),
      args: mapValue(field.args, extendArg)
    });
  }

  function extendArg(arg) {
    return _objectSpread({}, arg, {
      type: replaceType(arg.type)
    });
  }
}