Function validateValue

packages/codemirror-graphql/src/variables/lint.ts:112–217

(
  type?: GraphQLType,
  valueAST?: ParseValueOutput,
)

// Returns a list of validation errors in the form Array<[Node, String]>.
function validateValue(
  type?: GraphQLType,
  valueAST?: ParseValueOutput,
): any[][] {
  // TODO: Can't figure out the right type.
  if (!type || !valueAST) {
    return [];
  }

  // Validate non-nullable values.
  if (type instanceof GraphQLNonNull) {
    if (valueAST.kind === 'Null') {
      return [[valueAST, `Type "${type}" is non-nullable and cannot be null.`]];
    }
    return validateValue(type.ofType, valueAST);
  }

  if (valueAST.kind === 'Null') {
    return [];
  }

  // Validate lists of values, accepting a non-list as a list of one.
  if (type instanceof GraphQLList) {
    const itemType = type.ofType;
    if (valueAST.kind === 'Array') {
      const values = (valueAST as ParseArrayOutput).values || [];
      return mapCat(values, item => validateValue(itemType, item));
    }
    return validateValue(itemType, valueAST);
  }

  // Validate input objects.
  if (type instanceof GraphQLInputObjectType) {
    if (valueAST.kind !== 'Object') {
      return [[valueAST, `Type "${type}" must be an Object.`]];
    }

    // Validate each field in the input object.
    const providedFields = Object.create(null);
    const fieldErrors: any[][] = mapCat(
      (valueAST as ParseObjectOutput).members,
      member => {
        // TODO: Can't figure out the right type here
        const fieldName = member?.key?.value;
        providedFields[fieldName] = true;
        const inputField = type.getFields()[fieldName];
        if (!inputField) {
          return [
            [
              member.key,
              `Type "${type}" does not have a field "${fieldName}".`,
            ],
          ];
        }
        const fieldType = inputField ? inputField.type : undefined;
        return validateValue(fieldType, member.value);
      },
    );