npm 12 - drops `npm-shrinkwrap.json`

[MikeMcC399]

Situation

npm 12 drops npm-shrinkwrap.json used in this repo as a published lockfile. The npm 12.0.0 changelog states:

npm shrinkwrap is removed, the shrinkwrap config alias is removed, and npm-shrinkwrap.json is no longer loaded or honored at the project root or from inside dependency tarballs. Rename project-root npm-shrinkwrap.json to package-lock.json; use bundleDependencies if you need to ship a locked dependency tree.

npm install under npm 12 installs dependencies according to their SemVer range specified in package.json and ignores the lower locked versions specified in npm-shrinkwrap.json.

Example impact

If the repo is cloned and dependencies installed under npm 12, then npm test fails.

npm install ignores the locked prettier@3.6.2 and installs instead prettier@^3.6.2 from package.json which causes prettier@3.9.6 to be installed, and written into the new lockfile package-lock.json.

prettier@3.9.0 introduced formatting improvements which flagged a white space formatting issue in lib/reporter/logger.js that was not previously flagged.

Steps to reproduce

Ubuntu 24.04.4 LTS, Node.js 24.19.0, initially with npm 11.17.0

git clone https://github.com/nodejs/citgm
cd citgm
git clean -xfd # if repeating
npm install -g npm@12.0.2
npm install
npm test

Logs

$ npm test
npm notice run citgm@10.0.2 test
npm notice run npm run lint && npm run tap
npm notice run citgm@10.0.2 lint
npm notice run npm run lint:eslint && npm run lint:prettier
npm notice run citgm@10.0.2 lint:eslint
npm notice run eslint . --cache
npm notice run citgm@10.0.2 lint:prettier
npm notice run prettier --check .
Checking formatting...
[warn] lib/reporter/logger.js
[warn] Code style issues found in the above file. Run Prettier with --write to fix.

Suggestion

Review also how this impacts use of citgm when installing using npm install -g citgm as specified in the README > Installation section.

For the Prettier issue, that was used here more as an illustration of compatibility issues, update to latest and fix the formatting.