Notes about the icu directory.

How to upgrade ICU

• Make sure your node workspace is clean (clean git status) should be sufficient.
• Configure Node with the specific ICU version you want to upgrade to, for example:

./configure \
    --with-intl=small-icu \
    --with-icu-source=http://download.icu-project.org/files/icu4c/58.1/icu4c-58_1-src.tgz
make

(The equivalent vcbuild.bat commands should work also. Note that we use the .tgz and not the .zip here, that is because of line endings.)

• (note- may need to make changes in icu-generic.gyp or tools/icu/patches for version specific stuff)

• Verify the node build works

make test-ci

Also running

 new Intl.DateTimeFormat('es',{month:'long'}).format(new Date(9E8));

…Should return January not enero. (TODO here: improve testing)

• Now, copy deps/icu over to deps/icu-small

python tools/icu/shrink-icu-src.py

• Now, do a clean rebuild of node to test:

(TODO: fix this when these options become default)

./configure --with-intl=small-icu --with-icu-source=deps/icu-small
make

• Test this newly default-generated Node.js

process.versions.icu;
new Intl.DateTimeFormat('es',{month:'long'}).format(new Date(9E8));

(should return your updated ICU version number, and also January again.)

• You are ready to check in the updated deps/small-icu. This is a big commit, so make this a separate commit from other changes.

• Now, rebuild the Node license.

# clean up - remove deps/icu
make clean
tools/license-builder.sh

• Now, fix the default URL for the full-icu build in /configure, in the configure_intl() function. It should match the ICU URL used in the first step. When this is done, the following should build with full ICU.

# clean up
rm -rf out deps/icu deps/icu4c*
./configure --with-intl=full-icu --download=all
make
make test-ci

• commit the change to configure along with the updated LICENSE file.

---

Notes about these tools

The files in this directory were written for the node.js effort. It's the intent of their author (Steven R. Loomis / srl295) to merge them upstream into ICU, pending much discussion within the ICU-PMC.

icu_small.json is somewhat node-specific as it specifies a "small ICU" configuration file for the icutrim.py script. icutrim.py and iculslocs.cpp may themselves be superseded by components built into ICU in the future.

The following tickets were opened during this work, and their resolution may inform the reader as to the current state of icu-trim upstream:

• #10919 (experimental branch - may copy any source patches here)
• #10922 (data packaging improvements)
• #10923 (rewrite data building in python)

When/if components (not including the .json file) are merged into ICU, this code and configure will be updated to detect and use those variants rather than the ones in this directory.