amazon-route-53-dns-zone-file/src/validation/validator.ts

Makes DNS Zone File easy. Parses and validates BIND zone files and can be extended for custom features. Functionality is modular. Features are made open for extension and closed for runtime mutation. Written in TypeScript.

import { ParsingError } from '../errors/parsing_error';
import { ParserTypings } from '../parser/types_parser';
import { Validation } from './validation_types';
import { ErrorBuilder } from './error_builder';
import { createDefaultValidators } from './default_validators';

/** @mutates */
const mergeOptions = (
  target: Required<Validation.ValidationOptions>,
  partial: Validation.ValidationOptions
) => {
  const keys = Object.keys(partial) as Array<
    keyof Validation.ValidationOptions
  >;
  keys.forEach(key => {
    if (key === 'getErrorText') {
      target[key] = partial[key]!;
    } else if (Array.isArray(target[key])) {
      target[key] = [...target[key], ...partial[key]!];
    }
  });
};

export class Validator {
  public errors: ParsingError[] = [];
  public options: Required<Validation.ValidationOptions> = createDefaultValidators();
  private errorBuilder = new ErrorBuilder();

  constructor(options: Validation.ValidationOptions = {}) {
    this.mergeOptions(options);
  }

  private mergeOptions(partial: Validation.ValidationOptions) {
    mergeOptions(this.options, partial);
    this.errorBuilder.getErrorText = this.options.getErrorText;
    return this;
  }

  public validate(parser: ParserTypings.Parser): this {
    this.options.preValidators.forEach(validator => {
      try {
        validator(parser, this.errorBuilder);
      } catch (beforeError) {
        this.errors.push(beforeError);
      }
    });

    for (const [parsingLineNumber, entry] of parser.parsingMeta) {
      this.errorBuilder.update(parsingLineNumber, entry);

      this.options.loopValidators.forEach(validator => {
        try {
          validator(parser, this.errorBuilder);
        } catch (loopError) {
          this.errors.push(loopError);
        }
      });
    }

    this.errorBuilder.update(0, {} as any);
    this.options.postValidators.forEach(validator => {
      try {
        validator(parser, this.errorBuilder);
      } catch (afterError) {
        this.errors.push(afterError);
      }
    });

    return this;
  }
}