Changelog

Source: NEWS.md

checkstring (development version)

checkstring 0.2.1

CRAN release: 2026-09-28

• is_base64(), is_base64url(), is_doi(), is_email(), is_ipv4(), is_iso_datetime(), is_mime(), is_semver(), and is_uuid() no longer accept strings with a trailing newline, such as "1.0.0\n".
• is_base64() and is_base64url() now return FALSE for empty strings.
• is_cuid2() now rejects strings longer than 32 characters, the maximum CUID2 length.
• is_email() now rejects domain labels that end with a hyphen, such as "user@domain-.com".
• is_figi() now rejects the reserved prefixes BS, BM, GG, GB, GH, KY, and VG.
• is_ipv6() no longer accepts a trailing single colon after a compressed group, such as "1::2:".
• is_isbn() now rejects ISBN-13s that don’t start with 978 or 979, as well as ISMNs (9790).
• is_iso_datetime() now validates the timezone offset, rejecting out-of-range values such as "+99:99".
• is_ulid() now rejects ULIDs whose first character is greater than 7, which would overflow the 48-bit timestamp.

checkstring 0.2.0

CRAN release: 2026-06-29

• is_color_hex() validates hex color strings (#RGB, #RGBA, #RRGGBB, #RRGGBBAA).
• is_ipv6() validates IPv6 address strings, including compressed (::) and IPv4-embedded forms (#18).
• is_iso_date() and is_iso_datetime() validate ISO 8601 date and datetime strings.
• is_mime() validates MIME type strings against the IANA-registered top-level types.

checkstring 0.1.0

CRAN release: 2026-03-05

• Initial CRAN submission.