graphql/graphql.mjs

import { devAssert } from './jsutils/devAssert.mjs';
import { isPromise } from './jsutils/isPromise.mjs';
import { parse } from './language/parser.mjs';
import { validateSchema } from './type/validate.mjs';
import { validate } from './validation/validate.mjs';
import { execute } from './execution/execute.mjs';
/**
 * This is the primary entry point function for fulfilling GraphQL operations
 * by parsing, validating, and executing a GraphQL document along side a
 * GraphQL schema.
 *
 * More sophisticated GraphQL servers, such as those which persist queries,
 * may wish to separate the validation and execution phases to a static time
 * tooling step, and a server runtime step.
 *
 * Accepts either an object with named arguments, or individual arguments:
 *
 * schema:
 *    The GraphQL type system to use when validating and executing a query.
 * source:
 *    A GraphQL language formatted string representing the requested operation.
 * rootValue:
 *    The value provided as the first argument to resolver functions on the top
 *    level type (e.g. the query object type).
 * contextValue:
 *    The context value is provided as an argument to resolver functions after
 *    field arguments. It is used to pass shared information useful at any point
 *    during executing this query, for example the currently logged in user and
 *    connections to databases or other services.
 * variableValues:
 *    A mapping of variable name to runtime value to use for all variables
 *    defined in the requestString.
 * operationName:
 *    The name of the operation to use if requestString contains multiple
 *    possible operations. Can be omitted if requestString contains only
 *    one operation.
 * fieldResolver:
 *    A resolver function to use when one is not provided by the schema.
 *    If not provided, the default field resolver is used (which looks for a
 *    value or method on the source value with the field's name).
 * typeResolver:
 *    A type resolver function to use when none is provided by the schema.
 *    If not provided, the default type resolver is used (which looks for a
 *    `__typename` field or alternatively calls the `isTypeOf` method).
 */

export function graphql(args) {
  // Always return a Promise for a consistent API.
  return new Promise((resolve) => resolve(graphqlImpl(args)));
}
/**
 * The graphqlSync function also fulfills GraphQL operations by parsing,
 * validating, and executing a GraphQL document along side a GraphQL schema.
 * However, it guarantees to complete synchronously (or throw an error) assuming
 * that all field resolvers are also synchronous.
 */

export function graphqlSync(args) {
  const result = graphqlImpl(args); // Assert that the execution was synchronous.

  if (isPromise(result)) {
    throw new Error('GraphQL execution failed to complete synchronously.');
  }

  return result;
}

function graphqlImpl(args) {
  // Temporary for v15 to v16 migration. Remove in v17
  arguments.length < 2 ||
    devAssert(
      false,
      'graphql@16 dropped long-deprecated support for positional arguments, please pass an object instead.',
    );
  const {
    schema,
    source,
    rootValue,
    contextValue,
    variableValues,
    operationName,
    fieldResolver,
    typeResolver,
  } = args; // Validate Schema

  const schemaValidationErrors = validateSchema(schema);

  if (schemaValidationErrors.length > 0) {
    return {
      errors: schemaValidationErrors,
    };
  } // Parse

  let document;

  try {
    document = parse(source);
  } catch (syntaxError) {
    return {
      errors: [syntaxError],
    };
  } // Validate

  const validationErrors = validate(schema, document);

  if (validationErrors.length > 0) {
    return {
      errors: validationErrors,
    };
  } // Execute

  return execute({
    schema,
    document,
    rootValue,
    contextValue,
    variableValues,
    operationName,
    fieldResolver,
    typeResolver,
  });
}