The runtime pack shipped ICU's full icudt78l.dat (33.1 MB), and every
Intl executable gets a copy beside it. scr_intl.c answers its Intl forms
with ICU's break iterators, number and date formatters, calendars and
locale IDs, which never read the charset converters or the collation,
language, region, time zone name, unit, spell-out and transliterator
trees: 21.5 MB of the file.
- The pack build writes icudt78l.dat without those items
(ICU_DATA_DROPPED in icu-inputs.mjs). filterIcuData rewrites the data
file's table of contents to the remaining items, and the result is
checked against a pinned sha256 and size (11,653,984 B).
- tests/harness/icu-data-filter.test.ts runs every @requires-icu corpus
program under 47 locales and 3 time zones with the pack's data, with
the full data and in Node, and fails when the outputs differ, so an
Intl form that reads a dropped category fails there.
- intl-word-segmenter-dictionaries.ts segments Chinese, Japanese, Thai,
Lao, Khmer and Burmese text, which ICU breaks with the dictionaries in
brkitr/.
Node answers every locale-dependent Intl form from ICU, so a compiled
binary that must match it byte for byte has to run the same release over
the same data. vendor-inputs.ts pins ICU_VERSION = "78.3" beside the
other vendored versions and vendor-inputs.test.ts asserts it against
process.versions.icu, the oracle the differential corpus compares with.
ICU is not vendored. Its source tarball (icu4c-78.3-sources.tgz,
27,977,255 B) and its prebuilt data zip (icu4c-78.3-data-bin-l.zip,
12,836,659 B) come from unicode-org/icu's official release-78.3 assets,
each pinned by version and sha256 beside ICU_VERSION and mirrored in the
runtime packs' icu-inputs.mjs, with a unit test that keeps the two
identical. The tarball carries ICU's own sources.txt lists, which stay
the list of record: icuSourceList() reads them so the archive holds
exactly the units ICU's autoconf build compiles. ICU_CXX_TARGET names
the glibc floor the archive is built for.
The data (icudt78l.dat, 33,107,232 B) is shipped beside the executable,
never embedded: 970 source files and 33 MiB of compiled CLDR tables are
a download, not a reviewable tree in this repository.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Chris Tate