argsert.js 2.4 KB

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  1. import { YError } from './yerror.js';
  2. import { parseCommand } from './parse-command.js';
  3. const positionName = ['first', 'second', 'third', 'fourth', 'fifth', 'sixth'];
  4. export function argsert(arg1, arg2, arg3) {
  5. function parseArgs() {
  6. return typeof arg1 === 'object'
  7. ? [{ demanded: [], optional: [] }, arg1, arg2]
  8. : [
  9. parseCommand(`cmd ${arg1}`),
  10. arg2,
  11. arg3,
  12. ];
  13. }
  14. try {
  15. let position = 0;
  16. const [parsed, callerArguments, _length] = parseArgs();
  17. const args = [].slice.call(callerArguments);
  18. while (args.length && args[args.length - 1] === undefined)
  19. args.pop();
  20. const length = _length || args.length;
  21. if (length < parsed.demanded.length) {
  22. throw new YError(`Not enough arguments provided. Expected ${parsed.demanded.length} but received ${args.length}.`);
  23. }
  24. const totalCommands = parsed.demanded.length + parsed.optional.length;
  25. if (length > totalCommands) {
  26. throw new YError(`Too many arguments provided. Expected max ${totalCommands} but received ${length}.`);
  27. }
  28. parsed.demanded.forEach(demanded => {
  29. const arg = args.shift();
  30. const observedType = guessType(arg);
  31. const matchingTypes = demanded.cmd.filter(type => type === observedType || type === '*');
  32. if (matchingTypes.length === 0)
  33. argumentTypeError(observedType, demanded.cmd, position);
  34. position += 1;
  35. });
  36. parsed.optional.forEach(optional => {
  37. if (args.length === 0)
  38. return;
  39. const arg = args.shift();
  40. const observedType = guessType(arg);
  41. const matchingTypes = optional.cmd.filter(type => type === observedType || type === '*');
  42. if (matchingTypes.length === 0)
  43. argumentTypeError(observedType, optional.cmd, position);
  44. position += 1;
  45. });
  46. }
  47. catch (err) {
  48. console.warn(err.stack);
  49. }
  50. }
  51. function guessType(arg) {
  52. if (Array.isArray(arg)) {
  53. return 'array';
  54. }
  55. else if (arg === null) {
  56. return 'null';
  57. }
  58. return typeof arg;
  59. }
  60. function argumentTypeError(observedType, allowedTypes, position) {
  61. throw new YError(`Invalid ${positionName[position] || 'manyith'} argument. Expected ${allowedTypes.join(' or ')} but received ${observedType}.`);
  62. }