[nissa-seru]

This changes github-mcpl's CI to run the typecheck and the whole suite once, on Linux at Node 22.12.0, and adds a check that the server installs, builds and starts at Node 22.0.0, the floor engines declares, and at Node 24. CI at this head passed all three jobs. Nothing a user, operator or host of the server meets changes.

Problem

At main (7eaea03):

• CI runs one job, "Typecheck & Test (node 22)", on Linux with node-version: 22 (.github/workflows/ci.yml:14, :26), which takes a 22.x release: main's last CI run used v22.23.3, from the runner's cache. No job runs on another Node version.
• Nothing checks Node 22.0.0, the floor package.json's engines declares (>=22.0.0), and npm test can't run there. Its --experimental-test-isolation=none flag (package.json:13) is refused with "bad option" and exit 9 by every Node 22 release from 22.0.0 to 22.7.0, and taken by Node 22.8.0.

Changes

• "Typecheck & Test (node 22.12.0)": the same three steps as before (npm ci, npm run typecheck, npm test), on Linux at Node 22.12.0 exactly.
• "Install & Start (node 22.0.0)" and "Install & Start (node 24)": npm ci, npm run build and node scripts/ci-start-check.mjs, on Linux. Node 24 is given as 24, which takes a 24.x release, from the runner's cache when it has one, as 22 did. The matrix doesn't fail fast, so each Node version gets its own verdict. Each job has a 10-minute timeout.
• scripts/ci-start-check.mjs (new): it runs the built server, dist/src/index.js --stdio, with a throwaway configuration: an RSA key it generates in a new temporary directory, one example repository, polling off and no webhook port. It sends one MCPL initialize, and passes only on a JSON-RPC 2.0 result whose capabilities.experimental.mcpl is an object, followed by exit 0 once it closes the server's stdin. It fails by name, with the server's stderr, on no answer within 30 s, a line that isn't a JSON object, an answer without that result, an exit before answering, an exit other than 0 after it, or no exit within 10 s of stdin closing. Every ending after the server starts kills the server if it's still running and removes the temporary directory.
• README.md: the development section's "Node 22" now says npm test runs on 22.12 or newer.
• b899b4b, this head, moved the suite job from Node 22.8.0 to 22.12.0, and changed the README's "needs 22.8 or newer" to "runs on 22.12 or newer". This pull request's first CI run, at 57820ab, had the suite job at 22.8.0, where none of the 18 test files loaded (Tests, below).

Tests

On Linux, after npm ci from the lockfile:

• CI at this head (run 40770218205): "Typecheck & Test (node 22.12.0)" passed, with # tests 617, # pass 599, # fail 0 and # skipped 18 on Node v22.12.0. Both start legs passed, on Node v22.0.0 and v24.22.1.
• CI's first run, at 57820ab (run 40769830290): both start legs passed. The suite job, then at Node 22.8.0, failed: # tests 18, # fail 18, each test file not ok with a TypeError, Unknown file extension ".ts" for that file. Node 22.8.0 took the flag, but no test file loaded.
• The start check, on a machine of ours: it passed against the built server on Node 22.0.0 and on Node 24.22.1, each after npm ci and the build under that Node. No other Node 24 release ran. These runs were at 57820ab, whose scripts/ci-start-check.mjs is this head's.
• The start check fails when the server doesn't start right. Against twelve stand-ins written over the built entry point, each failure named its cause and exited 1: no answer (after 31 s), an exit 1 at once (with its stderr), an answer and then no exit (after 10 s), a JSON-RPC error, plain MCP without the mcpl capability, a line that isn't JSON, an exit 3 after answering, a JSON null line, an answer without "jsonrpc": "2.0", "mcpl": true, a result with an error beside it, and a 500-character line, shown cut at 200 characters. With dist/src/server.js deleted, it failed with the server's ERR_MODULE_NOT_FOUND stderr. No temporary directory was left after any of these runs.
• The Node floor: at main, npm test exited 9 on Node 22.0.0 with "node: bad option: --experimental-test-isolation=none". On a one-test file, node --test --experimental-test-isolation=none exited 9 with "bad option" on each of the ten Node releases from 22.0.0 to 22.7.0, and passed on 22.8.0.

Not verified

• Node 22.9 to 22.11. The suite hasn't run on those releases, so whether it loads there isn't shown.
• macOS and Windows. Neither the old workflow nor this one runs there. In package-lock.json, the only entries that set os or cpu are fsevents and 26 @esbuild/* packages, all development dependencies.

With other open pull requests

By git merge-tree against main 7eaea03 and each open pull request's head:

• Use @animalabs/mcpl-core 0.4.0, which needs Node 22.12.0 or later #16 merges cleanly with main and conflicts with this change in .github/workflows/ci.yml (the job's name and node-version, where Use @animalabs/mcpl-core 0.4.0, which needs Node 22.12.0 or later #16 has a Node 22 and 24 matrix) and in README.md's development line.
• update_branch: write only to a head that is nobody's base #14, Comments: keep only those one rule allows, outside the files #11 changes #15 and #11 merge cleanly with both.
• #4 and #6 already conflict with main, and this change adds no file in which they conflict.

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No changelog fragment: this changes CI and one README line.

Ogden-2688 made this change, and Agnes-984 made the calls on it. Crispin-2406 read it. Fiona-2757 wrote this description.