Philip Chimento b4c0aeda20 Bring existing toString options tests in sync with each other
Of the toString() methods that have options for printing a time with
seconds and fractional seconds, PlainTime seems to have the most
comprehensive set of tests. Bring all the others (Duration, Instant,
PlainDateTime, and ZonedDateTime) in sync with PlainTime, and edit the
PlainTime ones where necessary to include improvements from the others.

Tests:
  - fractionalseconddigits-invalid-string.js: copy and expand on
    PlainTime's more comprehensive set of invalid strings. Add assertion
    message. Fix front matter.
  - fractionalseconddigits-non-integer.js: Fix front matter.
  - fractionalseconddigits-out-of-range.js: make sure infinity is tested.
    Add assertion messages. Fix front matter.
  - fractionalseconddigits-undefined.js: copy PlainTime's more
    comprehensive test with whole minutes, whole seconds, and subseconds.
    Copy PlainTime's test of an empty function object. Add more
    descriptive variable names and assertion messages. Fix front matter.
  - fractionalseconddigits-wrong-type.js: inline and delete TemporalHelper
    used here; it was only good for this test anyway. Improve assertion
    messages.
  - smallestunit-valid-units.js: copy PlainTime's test with a second value
    with zero seconds even. Refactor repetitive tests into a loop. Copy
    the invalid unit "era" from the Instant test. Add assertion messages.
2022-04-13 10:46:20 +02:00
..
2020-06-24 12:26:41 -04:00
2020-06-24 12:26:41 -04:00