parseJSON.js 2.2 KB

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  1. "use strict";
  2. exports.parseJSON = parseJSON; /**
  3. * @name parseJSON
  4. * @category Common Helpers
  5. * @summary Parse a JSON date string
  6. *
  7. * @description
  8. * Converts a complete ISO date string in UTC time, the typical format for transmitting
  9. * a date in JSON, to a JavaScript `Date` instance.
  10. *
  11. * This is a minimal implementation for converting dates retrieved from a JSON API to
  12. * a `Date` instance which can be used with other functions in the `date-fns` library.
  13. * The following formats are supported:
  14. *
  15. * - `2000-03-15T05:20:10.123Z`: The output of `.toISOString()` and `JSON.stringify(new Date())`
  16. * - `2000-03-15T05:20:10Z`: Without milliseconds
  17. * - `2000-03-15T05:20:10+00:00`: With a zero offset, the default JSON encoded format in some other languages
  18. * - `2000-03-15T05:20:10+05:45`: With a positive or negative offset, the default JSON encoded format in some other languages
  19. * - `2000-03-15T05:20:10+0000`: With a zero offset without a colon
  20. * - `2000-03-15T05:20:10`: Without a trailing 'Z' symbol
  21. * - `2000-03-15T05:20:10.1234567`: Up to 7 digits in milliseconds field. Only first 3 are taken into account since JS does not allow fractional milliseconds
  22. * - `2000-03-15 05:20:10`: With a space instead of a 'T' separator for APIs returning a SQL date without reformatting
  23. *
  24. * For convenience and ease of use these other input types are also supported
  25. * via [toDate](https://date-fns.org/docs/toDate):
  26. *
  27. * - A `Date` instance will be cloned
  28. * - A `number` will be treated as a timestamp
  29. *
  30. * Any other input type or invalid date strings will return an `Invalid Date`.
  31. *
  32. * @param dateStr - A fully formed ISO8601 date string to convert
  33. *
  34. * @returns The parsed date in the local time zone
  35. */
  36. function parseJSON(dateStr) {
  37. const parts = dateStr.match(
  38. /(\d{4})-(\d{2})-(\d{2})[T ](\d{2}):(\d{2}):(\d{2})(?:\.(\d{0,7}))?(?:Z|(.)(\d{2}):?(\d{2})?)?/,
  39. );
  40. if (parts) {
  41. // Group 8 matches the sign
  42. return new Date(
  43. Date.UTC(
  44. +parts[1],
  45. +parts[2] - 1,
  46. +parts[3],
  47. +parts[4] - (+parts[9] || 0) * (parts[8] == "-" ? -1 : 1),
  48. +parts[5] - (+parts[10] || 0) * (parts[8] == "-" ? -1 : 1),
  49. +parts[6],
  50. +((parts[7] || "0") + "00").substring(0, 3),
  51. ),
  52. );
  53. }
  54. return new Date(NaN);
  55. }