NPM registry: more robust, work on Windows

- Run `npm rm` in correct dir
- Encode args in `npm conf rm` command for Powershell
- Don't cleanup in exit handler, this might not complete.
  Instead, do it on startup.
- Different cleanup command for Windows and Linux
- Explicitly close server, instead of relying on process.exit()
- Make scope configurable

.registry/server.js

@@ -1,17 +1,22 @@
 const { exec } = require ('child_process')
+const isWin = process.platform === 'win32'
 const express = require ('express')
 const fs = require ('fs')
 const app = express()
 
 const { PORT=4444 } = process.env
-const [,,port=PORT] = process.argv
+const [,,port=PORT,scope='@capire'] = process.argv
 const cwd = __dirname
 
+// clean up on start (exit handler might not complete on Windows)
+exec(isWin ? 'del *.tgz' : 'rm *.tgz', {cwd})
+
+
 app.use('/-/:tarball', (req,res,next) => {
   console.debug ('GET', req.params)
   try {
     const { tarball } = req.params
-    const [, pkg ] = /^capire-(\w+)/.exec(tarball)
+    const [, pkg ] = /^\w+-(\w+)/.exec(tarball)
     fs.lstat(tarball,(err => {
       if (err) exec(`npm pack ../${pkg}`,{cwd},next)
       else next()
@@ -28,9 +33,9 @@ app.get('/*', (req,res)=>{
   const url = decodeURIComponent(req.url)
   console.debug ('GET',url)
   try {
-    const [, capire, pkg ] = /^\/(@capire)\/(\w+)/.exec(url)
-    const package = require (`${capire}/${pkg}/package.json`)
-    const tarball = `capire-${pkg}-${package.version}.tgz`
+    const [, scpe, pkg ] = /^\/(@\w+)\/(\w+)/.exec(url)
+    const package = require (`${scpe}/${pkg}/package.json`)
+    const tarball = `${scpe.slice(1)}-${pkg}-${package.version}.tgz`
     // https://github.com/npm/registry/blob/master/docs/responses/package-metadata.md
     res.json({
       "name": package.name,
@@ -53,18 +58,18 @@ app.get('/*', (req,res)=>{
   }
 })
 
-app.listen(port, ()=>{
-  console.log (`npm set @capire:registry=http://localhost:${port}`)
-  console.log (`@capire registry listening on http://localhost:${port}`)
-  exec(`npm set @capire:registry=http://localhost:${port}`)
+const server = app.listen(port, ()=>{
+  const url = `http://localhost:${port}`
+  console.log (`npm set ${scope}:registry=${url}`)
+  exec(`npm set ${scope}:registry=${url}`)
+  console.log (`${scope} registry listening on ${url}`)
 })
 
 const _exit = ()=>{
-  console.log ('\nnpm conf rm @capire:registry')
-  exec('npm conf rm @capire:registry')
-  exec('rm *.tgz')
-  process.exit()
+  server.close()
+  exec(`npm conf rm "${scope}:registry"`, ()=> { process.exit() })
 }
+
 process.on ('SIGTERM',_exit)
 process.on ('SIGHUP',_exit)
 process.on ('SIGINT',_exit)