prune: Rewrite to use npm@3 plumbing

PR-URL: #15090
Credit: @iarna
Reviewed-By: @zkat

lib/prune.js

@@ -1,54 +1,66 @@
 // prune extraneous packages.
 
 module.exports = prune
+module.exports.Pruner = Pruner
 
 prune.usage = 'npm prune [[<@scope>/]<pkg>...] [--production]'
 
-var readInstalled = require('read-installed')
 var npm = require('./npm.js')
-var path = require('path')
-var readJson = require('read-package-json')
 var log = require('npmlog')
+var util = require('util')
+var moduleName = require('./utils/module-name.js')
+var Installer = require('./install.js').Installer
+var isExtraneous = require('./install/is-extraneous.js')
+var isDev = require('./install/is-dev-dep.js')
+var removeDeps = require('./install/deps.js').removeDeps
+var loadExtraneous = require('./install/deps.js').loadExtraneous
+var chain = require('slide').chain
 
 prune.completion = require('./utils/completion/installed-deep.js')
 
 function prune (args, cb) {
-  // check if is a valid package.json file
-  var jsonFile = path.resolve(npm.dir, '..', 'package.json')
-  readJson(jsonFile, log.warn, function (er) {
-    if (er) return cb(er)
-    next()
-  })
-
-  function next () {
-    var opt = {
-      depth: npm.config.get('depth'),
-      dev: !npm.config.get('production') || npm.config.get('dev')
-    }
-    readInstalled(npm.prefix, opt, function (er, data) {
-      if (er) return cb(er)
-      prune_(args, data, cb)
-    })
-  }
+  var dryrun = !!npm.config.get('dry-run')
+  new Pruner('.', dryrun, args).run(cb)
 }
 
-function prune_ (args, data, cb) {
-  npm.commands.unbuild(prunables(args, data, []), cb)
+function Pruner (where, dryrun, args) {
+  Installer.call(this, where, dryrun, args)
 }
+util.inherits(Pruner, Installer)
+
+Pruner.prototype.loadAllDepsIntoIdealTree = function (cb) {
+  log.silly('uninstall', 'loadAllDepsIntoIdealtree')
+
+  var cg = this.progress.loadAllDepsIntoIdealTree
+  var steps = []
 
-function prunables (args, data, seen) {
-  var deps = data.dependencies || {}
-  return Object.keys(deps).map(function (d) {
-    if (typeof deps[d] !== 'object' || seen.indexOf(deps[d]) !== -1) return null
-    seen.push(deps[d])
-    if (deps[d].extraneous && (args.length === 0 || args.indexOf(d) !== -1)) {
-      var extra = deps[d]
-      delete deps[d]
-      return extra.path
-    }
-    return prunables(args, deps[d], seen)
-  }).filter(function (d) { return d !== null })
-  .reduce(function FLAT (l, r) {
-    return l.concat(Array.isArray(r) ? r.reduce(FLAT, []) : r)
-  }, [])
+  var self = this
+  var excludeDev = npm.config.get('production') || /^prod(uction)?$/.test(npm.config.get('only'))
+  function shouldPrune (child) {
+    if (isExtraneous(child)) return true
+    if (!excludeDev) return false
+    var childName = moduleName(child)
+    var isChildDev = function (parent) { return isDev(parent, childName) }
+    if (child.requiredBy.every(isChildDev)) return true
+  }
+  function getModuleName (child) {
+    // wrapping because moduleName doesn't like extra args and we're called
+    // from map.
+    return moduleName(child)
+  }
+  function matchesArg (name) {
+    return self.args.length === 0 || self.args.indexOf(name) !== -1
+  }
+  function nameObj (name) {
+    return {name: name}
+  }
+  var toPrune = this.currentTree.children.filter(shouldPrune).map(getModuleName).filter(matchesArg).map(nameObj)
+
+  steps.push(
+    [removeDeps, toPrune, this.idealTree, null, cg.newGroup('removeDeps')],
+    [loadExtraneous, this.idealTree, cg.newGroup('loadExtraneous')])
+  chain(steps, cb)
 }
+
+Pruner.prototype.runPreinstallTopLevelLifecycles = function (cb) { cb() }
+Pruner.prototype.runPostinstallTopLevelLifecycles = function (cb) { cb() }

test/tap/prune.js

@@ -107,7 +107,7 @@ test('npm prune', function (t) {
   ], EXEC_OPTS, function (err, code, stderr) {
     t.ifErr(err, 'prune finished successfully')
     t.notOk(code, 'exit ok')
-    t.equal(stderr, 'unbuild mkdirp@0.3.5\n')
+    t.equal(stderr, '- mkdirp@0.3.5 node_modules/mkdirp\n')
     t.end()
   })
 })