feat: limit concurrency of root build script

Should fixes https://xcp-ng.org/forum/post/54567

scripts/run-script.js

@@ -5,6 +5,7 @@
 const { delimiter } = require('path')
 const { forEach, fromEvent } = require('promise-toolbox')
 const { spawn } = require('child_process')
+const getopts = require('getopts')
 
 const { getPackages } = require('./utils')
 
@@ -14,37 +15,46 @@ const { env } = process
 //
 // TODO: https://docs.npmjs.com/misc/scripts#environment
 require('exec-promise')(args => {
-  const parallel = args[0] === '--parallel'
-  const script = args[parallel ? 1 : 0]
+  const {
+    concurrency,
+    parallel,
+    _: [script],
+  } = getopts(args, {
+    boolean: ['parallel'],
+    string: ['concurrency'],
+  })
 
   let errors = 0
   return getPackages(true)
-    [parallel ? 'map' : 'forEach'](({ dir, name, package: { scripts } }) => {
-      if (scripts == null) {
-        return
-      }
-
-      const spawnOpts = {
-        cwd: dir,
-        env: Object.assign({}, env, {
-          PATH: `${dir}/node_modules/.bin${delimiter}${env.PATH}`,
-        }),
-        shell: true,
-        stdio: 'inherit',
-      }
-      return forEach.call([`pre${script}`, script, `post${script}`], script => {
-        const command = scripts[script]
-        if (command !== undefined) {
-          console.log(`* ${name}:${script} −`, command)
-          return fromEvent(spawn(command, spawnOpts), 'exit').then(code => {
-            if (code !== 0) {
-              ++errors
-              console.log(`* ${name}:${script} − Error:`, code)
-            }
-          })
+    [parallel ? 'map' : 'forEach'](
+      ({ dir, name, package: { scripts } }) => {
+        if (scripts == null) {
+          return
         }
-      })
-    })
+
+        const spawnOpts = {
+          cwd: dir,
+          env: Object.assign({}, env, {
+            PATH: `${dir}/node_modules/.bin${delimiter}${env.PATH}`,
+          }),
+          shell: true,
+          stdio: 'inherit',
+        }
+        return forEach.call([`pre${script}`, script, `post${script}`], script => {
+          const command = scripts[script]
+          if (command !== undefined) {
+            console.log(`* ${name}:${script} −`, command)
+            return fromEvent(spawn(command, spawnOpts), 'exit').then(code => {
+              if (code !== 0) {
+                ++errors
+                console.log(`* ${name}:${script} − Error:`, code)
+              }
+            })
+          }
+        })
+      },
+      { concurrency: concurrency ? Number(concurrency) : undefined }
+    )
     .then(() => {
       if (errors !== 0) {
         throw errors

scripts/utils.js

@@ -1,5 +1,6 @@
 'use strict'
 
+const { asyncEach } = require('@vates/async-each')
 const { forEach, fromCallback } = require('promise-toolbox')
 const { join } = require('path')
 const fs = require('fs')
@@ -34,7 +35,7 @@ exports.getPackages = (readPackageJson = false) => {
       : pkgs
   })
   p.forEach = fn => p.then(pkgs => forEach.call(pkgs, fn))
-  p.map = fn => p.then(pkgs => Promise.all(pkgs.map(fn))).then(noop)
+  p.map = (fn, opts) => p.then(pkgs => asyncEach(pkgs, fn, opts)).then(noop)
   return p
 }