env-bootstrap

1// env-bootstrap: per-project shell setup done once, not in every command.
2// Claude ran `nvm use 22` 140 times (backend-mastery-course) and sourced
3// .env.clone.local 120+ times (pebbo_mvp-oct). Here Node goes on PATH at
4// session start, the env file is loaded into each Bash call, and Claude is told.
5
6import type { EngineInterface, Register } from 'claude-code'
7
8type Project = { dir: string; node?: string; envFile?: string }
9
10// Paths relative to $HOME. Add a row to cover another repo.
11const PROJECTS: Project[] = [
12  { dir: 'Developer/backend-mastery-course', node: '22' },
13  { dir: 'Developer/work/Pebbo/pebbo_mvp-oct', envFile: '.env.clone.local' },
14]
15
16const NVM_PREFIX = /(?:source|\.)\s+\S*nvm\.sh\s*(?:>\s*\/dev\/null\s*)?(?:2>&1\s*)?(?:&&|;)\s*/g
17const NVM_USE = /nvm use\s+\S*\s*(?:>\s*\/dev\/null\s*)?(?:2>&1\s*)?(?:&&|;)\s*/g
18
19let active: (Project & { root: string }) | null = null
20
21async function pick($: EngineInterface, cwd: string): Promise<void> {
22  const home = (await $.env.get('HOME')) ?? ''
23  const hit = PROJECTS.find(p => cwd === `${home}/${p.dir}` || cwd.startsWith(`${home}/${p.dir}/`))
24  active = hit === undefined ? null : { ...hit, root: `${home}/${hit.dir}` }
25  if (active?.node === undefined) return
26
27  const versions = (await $.fs.list(`${home}/.nvm/versions/node`))
28    .map(f => f.name)
29    .filter(n => n.startsWith(`v${active?.node}.`))
30    .sort((a, b) => a.localeCompare(b, undefined, { numeric: true }))
31  const latest = versions.pop()
32  if (latest === undefined) return void $.ui.toast(`env-bootstrap: no Node ${active.node} under ~/.nvm`)
33  const path = (await $.env.get('PATH')) ?? ''
34  await $.env.set('PATH', `${home}/.nvm/versions/node/${latest}/bin:${path}`)
35}
36
37export const register: Register = on => {
38  on('session.start', async ($, e, next) => {
39    await pick($, e.cwd)
40    if (active !== null) {
41      $.ui.status(`env: ${[active.node && `node ${active.node}`, active.envFile].filter(Boolean).join(' · ')}`)
42    }
43    return next(e)
44  })
45
46  on('prompt.context', async ($, e, next) => {
47    if (active === null) return next(e)
48    const lines = [
49      active.node && `Node ${active.node} is already first on PATH. Do not run nvm or source nvm.sh.`,
50      active.envFile &&
51        `${active.envFile} is loaded automatically into every Bash call in ${active.root}. Do not source it yourself.`,
52    ].filter(Boolean)
53    return next({ ...e, blocks: [...e.blocks, { name: 'env-bootstrap', text: lines.join('\n') }] })
54  })
55
56  on('tool.call', { tool: 'Bash' }, ($, e, next) => {
57    if (active === null) return next(e)
58    let command = e.command
59    if (active.node !== undefined) command = command.replace(NVM_PREFIX, '').replace(NVM_USE, '')
60    if (active.envFile !== undefined && !command.includes(active.envFile)) {
61      command = `set -a; . "${active.root}/${active.envFile}" 2>/dev/null; set +a; ${command}`
62    }
63    return command === e.command ? next(e) : next({ ...e, command })
64  })
65}
66