graphql/utilities/TypeInfo.mjs

A Query Language and Runtime which can target any service.

import find from '../polyfills/find';
import { Kind } from '../language/kinds';
import { isObjectType, isInterfaceType, isEnumType, isInputObjectType, isListType, isCompositeType, isInputType, isOutputType, getNullableType, getNamedType } from '../type/definition';
import { SchemaMetaFieldDef, TypeMetaFieldDef, TypeNameMetaFieldDef } from '../type/introspection';
import { typeFromAST } from './typeFromAST';
/**
 * TypeInfo is a utility class which, given a GraphQL schema, can keep track
 * of the current field and type definitions at any point in a GraphQL document
 * AST during a recursive descent by calling `enter(node)` and `leave(node)`.
 */

export var TypeInfo =
/*#__PURE__*/
function () {
  function TypeInfo(schema, // NOTE: this experimental optional second parameter is only needed in order
  // to support non-spec-compliant codebases. You should never need to use it.
  // It may disappear in the future.
  getFieldDefFn, // Initial type may be provided in rare cases to facilitate traversals
  // beginning somewhere other than documents.
  initialType) {
    this._schema = schema;
    this._typeStack = [];
    this._parentTypeStack = [];
    this._inputTypeStack = [];
    this._fieldDefStack = [];
    this._defaultValueStack = [];
    this._directive = null;
    this._argument = null;
    this._enumValue = null;
    this._getFieldDef = getFieldDefFn || getFieldDef;

    if (initialType) {
      if (isInputType(initialType)) {
        this._inputTypeStack.push(initialType);
      }

      if (isCompositeType(initialType)) {
        this._parentTypeStack.push(initialType);
      }

      if (isOutputType(initialType)) {
        this._typeStack.push(initialType);
      }
    }
  }

  var _proto = TypeInfo.prototype;

  _proto.getType = function getType() {
    if (this._typeStack.length > 0) {
      return this._typeStack[this._typeStack.length - 1];
    }
  };

  _proto.getParentType = function getParentType() {
    if (this._parentTypeStack.length > 0) {
      return this._parentTypeStack[this._parentTypeStack.length - 1];
    }
  };

  _proto.getInputType = function getInputType() {
    if (this._inputTypeStack.length > 0) {
      return this._inputTypeStack[this._inputTypeStack.length - 1];
    }
  };

  _proto.getParentInputType = function getParentInputType() {
    if (this._inputTypeStack.length > 1) {
      return this._inputTypeStack[this._inputTypeStack.length - 2];
    }
  };

  _proto.getFieldDef = function getFieldDef() {
    if (this._fieldDefStack.length > 0) {
      return this._fieldDefStack[this._fieldDefStack.length - 1];
    }
  };

  _proto.getDefaultValue = function getDefaultValue() {
    if (this._defaultValueStack.length > 0) {
      return this._defaultValueStack[this._defaultValueStack.length - 1];
    }
  };

  _proto.getDirective = function getDirective() {
    return this._directive;
  };

  _proto.getArgument = function getArgument() {
    return this._argument;
  };

  _proto.getEnumValue = function getEnumValue() {
    return this._enumValue;
  };

  _proto.enter = function enter(node) {
    var schema = this._schema; // Note: many of the types below are explicitly typed as "mixed" to drop
    // any assumptions of a valid schema to ensure runtime types are properly
    // checked before continuing since TypeInfo is used as part of validation
    // which occurs before guarantees of schema and document validity.

    switch (node.kind) {
      case Kind.SELECTION_SET:
        {
          var namedType = getNamedType(this.getType());

          this._parentTypeStack.push(isCompositeType(namedType) ? namedType : undefined);

          break;
        }

      case Kind.FIELD:
        {
          var parentType = this.getParentType();
          var fieldDef;
          var fieldType;

          if (parentType) {
            fieldDef = this._getFieldDef(schema, parentType, node);

            if (fieldDef) {
              fieldType = fieldDef.type;
            }
          }

          this._fieldDefStack.push(fieldDef);

          this._typeStack.push(isOutputType(fieldType) ? fieldType : undefined);

          break;
        }

      case Kind.DIRECTIVE:
        this._directive = schema.getDirective(node.name.value);
        break;

      case Kind.OPERATION_DEFINITION:
        {
          var type;

          if (node.operation === 'query') {
            type = schema.getQueryType();
          } else if (node.operation === 'mutation') {
            type = schema.getMutationType();
          } else if (node.operation === 'subscription') {
            type = schema.getSubscriptionType();
          }

          this._typeStack.push(isObjectType(type) ? type : undefined);

          break;
        }

      case Kind.INLINE_FRAGMENT:
      case Kind.FRAGMENT_DEFINITION:
        {
          var typeConditionAST = node.typeCondition;
          var outputType = typeConditionAST ? typeFromAST(schema, typeConditionAST) : getNamedType(this.getType());

          this._typeStack.push(isOutputType(outputType) ? outputType : undefined);

          break;
        }

      case Kind.VARIABLE_DEFINITION:
        {
          var inputType = typeFromAST(schema, node.type);

          this._inputTypeStack.push(isInputType(inputType) ? inputType : undefined);

          break;
        }

      case Kind.ARGUMENT:
        {
          var argDef;
          var argType;
          var fieldOrDirective = this.getDirective() || this.getFieldDef();

          if (fieldOrDirective) {
            argDef = find(fieldOrDirective.args, function (arg) {
              return arg.name === node.name.value;
            });

            if (argDef) {
              argType = argDef.type;
            }
          }

          this._argument = argDef;

          this._defaultValueStack.push(argDef ? argDef.defaultValue : undefined);

          this._inputTypeStack.push(isInputType(argType) ? argType : undefined);

          break;
        }

      case Kind.LIST:
        {
          var listType = getNullableType(this.getInputType());
          var itemType = isListType(listType) ? listType.ofType : listType; // List positions never have a default value.

          this._defaultValueStack.push(undefined);

          this._inputTypeStack.push(isInputType(itemType) ? itemType : undefined);

          break;
        }

      case Kind.OBJECT_FIELD:
        {
          var objectType = getNamedType(this.getInputType());
          var inputFieldType;
          var inputField;

          if (isInputObjectType(objectType)) {
            inputField = objectType.getFields()[node.name.value];

            if (inputField) {
              inputFieldType = inputField.type;
            }
          }

          this._defaultValueStack.push(inputField ? inputField.defaultValue : undefined);

          this._inputTypeStack.push(isInputType(inputFieldType) ? inputFieldType : undefined);

          break;
        }

      case Kind.ENUM:
        {
          var enumType = getNamedType(this.getInputType());
          var enumValue;

          if (isEnumType(enumType)) {
            enumValue = enumType.getValue(node.value);
          }

          this._enumValue = enumValue;
          break;
        }
    }
  };

  _proto.leave = function leave(node) {
    switch (node.kind) {
      case Kind.SELECTION_SET:
        this._parentTypeStack.pop();

        break;

      case Kind.FIELD:
        this._fieldDefStack.pop();

        this._typeStack.pop();

        break;

      case Kind.DIRECTIVE:
        this._directive = null;
        break;

      case Kind.OPERATION_DEFINITION:
      case Kind.INLINE_FRAGMENT:
      case Kind.FRAGMENT_DEFINITION:
        this._typeStack.pop();

        break;

      case Kind.VARIABLE_DEFINITION:
        this._inputTypeStack.pop();

        break;

      case Kind.ARGUMENT:
        this._argument = null;

        this._defaultValueStack.pop();

        this._inputTypeStack.pop();

        break;

      case Kind.LIST:
      case Kind.OBJECT_FIELD:
        this._defaultValueStack.pop();

        this._inputTypeStack.pop();

        break;

      case Kind.ENUM:
        this._enumValue = null;
        break;
    }
  };

  return TypeInfo;
}();
/**
 * Not exactly the same as the executor's definition of getFieldDef, in this
 * statically evaluated environment we do not always have an Object type,
 * and need to handle Interface and Union types.
 */

function getFieldDef(schema, parentType, fieldNode) {
  var name = fieldNode.name.value;

  if (name === SchemaMetaFieldDef.name && schema.getQueryType() === parentType) {
    return SchemaMetaFieldDef;
  }

  if (name === TypeMetaFieldDef.name && schema.getQueryType() === parentType) {
    return TypeMetaFieldDef;
  }

  if (name === TypeNameMetaFieldDef.name && isCompositeType(parentType)) {
    return TypeNameMetaFieldDef;
  }

  if (isObjectType(parentType) || isInterfaceType(parentType)) {
    return parentType.getFields()[name];
  }
}