validate.ts

import { devAssert } from '../jsutils/devAssert';
import type { Maybe } from '../jsutils/Maybe';

import { GraphQLError } from '../error/GraphQLError';

import type { DocumentNode } from '../language/ast';
import { visit, visitInParallel } from '../language/visitor';

import type { GraphQLSchema } from '../type/schema';
import { assertValidSchema } from '../type/validate';

import { TypeInfo, visitWithTypeInfo } from '../utilities/TypeInfo';

import { specifiedRules, specifiedSDLRules } from './specifiedRules';
import type { SDLValidationRule, ValidationRule } from './ValidationContext';
import { SDLValidationContext, ValidationContext } from './ValidationContext';

/**
 * Implements the "Validation" section of the spec.
 *
 * Validation runs synchronously, returning an array of encountered errors, or
 * an empty array if no errors were encountered and the document is valid.
 *
 * A list of specific validation rules may be provided. If not provided, the
 * default list of rules defined by the GraphQL specification will be used.
 *
 * Each validation rules is a function which returns a visitor
 * (see the language/visitor API). Visitor methods are expected to return
 * GraphQLErrors, or Arrays of GraphQLErrors when invalid.
 *
 * Validate will stop validation after a `maxErrors` limit has been reached.
 * Attackers can send pathologically invalid queries to induce a DoS attack,
 * so by default `maxErrors` set to 100 errors.
 *
 * Optionally a custom TypeInfo instance may be provided. If not provided, one
 * will be created from the provided schema.
 */
export function validate(
  schema: GraphQLSchema,
  documentAST: DocumentNode,
  rules: ReadonlyArray<ValidationRule> = specifiedRules,
  options?: { maxErrors?: number },

  /** @deprecated will be removed in 17.0.0 */
  typeInfo: TypeInfo = new TypeInfo(schema),
): ReadonlyArray<GraphQLError> {
  const maxErrors = options?.maxErrors ?? 100;

  devAssert(documentAST, 'Must provide document.');
  // If the schema used for validation is invalid, throw an error.
  assertValidSchema(schema);

  const abortObj = Object.freeze({});
  const errors: Array<GraphQLError> = [];
  const context = new ValidationContext(
    schema,
    documentAST,
    typeInfo,
    (error) => {
      if (errors.length >= maxErrors) {
        errors.push(
          new GraphQLError(
            'Too many validation errors, error limit reached. Validation aborted.',
          ),
        );
        // eslint-disable-next-line @typescript-eslint/no-throw-literal
        throw abortObj;
      }
      errors.push(error);
    },
  );

  // This uses a specialized visitor which runs multiple visitors in parallel,
  // while maintaining the visitor skip and break API.
  const visitor = visitInParallel(rules.map((rule) => rule(context)));

  // Visit the whole document with each instance of all provided rules.
  try {
    visit(documentAST, visitWithTypeInfo(typeInfo, visitor));
  } catch (e) {
    if (e !== abortObj) {
      throw e;
    }
  }
  return errors;
}

/**
 * @internal
 */
export function validateSDL(
  documentAST: DocumentNode,
  schemaToExtend?: Maybe<GraphQLSchema>,
  rules: ReadonlyArray<SDLValidationRule> = specifiedSDLRules,
): ReadonlyArray<GraphQLError> {
  const errors: Array<GraphQLError> = [];
  const context = new SDLValidationContext(
    documentAST,
    schemaToExtend,
    (error) => {
      errors.push(error);
    },
  );

  const visitors = rules.map((rule) => rule(context));
  visit(documentAST, visitInParallel(visitors));
  return errors;
}

/**
 * Combine multiple errors into a single error, whose message
 * contains the error messages and their line:column on separate lines.
 */
function combineErrorsWithLocation(errors: ReadonlyArray<GraphQLError>): Error {
  const errorMessageWithLocations = errors
    .map((error) => {
      if (!error.locations?.length) {
        return error.message;
      }

      const locations =
        error.locations
          .map(({ line, column }) => `${line}:${column}`)
          .join(', ') ?? '';
      return `${error.message} (${locations})`;
    })
    .join('\n\n');

  return new Error(errorMessageWithLocations);
}

/**
 * Utility function which asserts a SDL document is valid by throwing an error
 * if it is invalid.
 *
 * @internal
 */
export function assertValidSDL(documentAST: DocumentNode): void {
  const errors = validateSDL(documentAST);
  if (errors.length !== 0) {
    throw combineErrorsWithLocation(errors);
  }
}

/**
 * Utility function which asserts a SDL document is valid by throwing an error
 * if it is invalid.
 *
 * @internal
 */
export function assertValidSDLExtension(
  documentAST: DocumentNode,
  schema: GraphQLSchema,
): void {
  const errors = validateSDL(documentAST, schema);
  if (errors.length !== 0) {
    throw combineErrorsWithLocation(errors);
  }
}