From ae4a1350d697d2699350ec11b78b8cf74d6d2468 Mon Sep 17 00:00:00 2001
From: "Rico Sta. Cruz" <rstacruz@users.noreply.github.com>
Date: Sat, 30 Jan 2016 01:19:47 +0800
Subject: [PATCH] Continue refactoring

---
 lib/install.js | 93 ++++++++++++++++++++++++++++++++------------------
 1 file changed, 59 insertions(+), 34 deletions(-)

diff --git a/lib/install.js b/lib/install.js
index 546ff421f6..d2e4c753a8 100644
--- a/lib/install.js
+++ b/lib/install.js
@@ -35,43 +35,60 @@ var fs = require('mz/fs')
  * - symlink bins
  */
 
-module.exports = function install (ctx, pkg, modules, options) {
-  debug('installing ' + pkg)
-
-  var keypath = (options && options.keypath || [])
-  var pkgSpec = npa(pkg) // { raw, name, scope, type, spec, rawSpec }
-  var pkgData  // { name, version, ... }
-  var fullname // 'lodash@4.0.0'
-  var dist     // { shasum, tarball }
-  var log = ctx.log(pkgSpec) // function
+module.exports = function install (ctx, pkgSpec, modules, options) {
+  debug('installing ' + pkgSpec)
   if (!ctx.fetches) ctx.fetches = {}
 
-  var paths = {
-    modules: modules,
-    store: join(ctx.root, 'node_modules', '.store'),
-    tmp: join(ctx.root, 'node_modules', '.tmp', getUuid()),
-    target: undefined // store + '/lodash@4.0.0'
+  var pkg = {
+    // Preliminary spec data
+    // => { raw, name, scope, type, spec, rawSpec }
+    spec: npa(pkgSpec),
+
+    // Dependency path to the current package
+    // => ['babel-core@6.4.5', 'babylon@6.4.5', 'babel-runtime@5.8.35']
+    keypath: (options && options.keypath || []),
+
+    // Full name of package => 'lodash@4.0.0'
+    fullname: undefined,
+
+    // Distribution data from resolve() => { shasum, tarball }
+    dist: undefined,
+
+    // package.json data as retrieved from resolve() => { name, version, ... }
+    data: undefined
   }
 
-  return fs.stat(join(modules, pkgSpec.name, 'package.json'))
+  var paths = {
+    modules: modules, // './node_modules'
+
+    // Final destination
+    store: join(ctx.root, 'node_modules', '.store'),
+
+    // Temporary destination while building
+    tmp: join(ctx.root, 'node_modules', '.tmp', getUuid()),
+
+    // Final destination => store + '/lodash@4.0.0'
+    target: undefined
+  }
+
+  var log = ctx.log(pkg.spec) // function
+
+  return fs.stat(join(modules, pkg.spec.name, 'package.json'))
     .catch(err => {
       if (err.code !== 'ENOENT') throw err
-      return resolve(pkgSpec)
+      return resolve(pkg.spec)
         .then(set)
-        .then(_ => log('resolved', pkgData))
+        .then(_ => log('resolved', pkg.data))
         .then(_ => fs.stat(join(paths.target, 'package.json'))) // todo: verify version?
         .catch(err => {
           if (err.code !== 'ENOENT') throw err
-          var isCircular = keypath.indexOf(fullname) > -1
-          if (isCircular) {
-            return Promise.resolve()
-          } else {
-            return memoize(ctx.fetches, fullname,
-              _ => doFetch(ctx, paths, dist, pkgData, keypath.concat(fullname), log))
-          }
+          return isCircular(pkg)
+            ? Promise.resolve()
+            : memoize(ctx.fetches, pkg.fullname,
+              _ => doFetch(ctx, paths, pkg, log))
         })
         .then(_ => mkdirp(paths.modules))
-        .then(_ => symlinkToModules(paths.target, pkgSpec, paths.modules))
+        .then(_ => symlinkToModules(paths.target, pkg.spec, paths.modules))
     })
     .then(_ => log('done'))
     .catch(err => {
@@ -81,15 +98,15 @@ module.exports = function install (ctx, pkg, modules, options) {
 
   // set metadata as fetched from resolve()
   function set (res) {
-    pkgData = res
-    fullname = '' + res.name.replace('/', '!') + '@' + res.version
-    paths.target = join(paths.store, fullname)
-    dist = res.dist
+    pkg.data = res
+    pkg.fullname = '' + res.name.replace('/', '!') + '@' + res.version
+    pkg.dist = res.dist
+    paths.target = join(paths.store, pkg.fullname)
   }
 }
 
 // perform a fetch to `.store/lodash@4.0.0` (paths.target)
-function doFetch (ctx, paths, dist, pkgData, keypath, log) {
+function doFetch (ctx, paths, pkg, log) {
   var installAll = require('./install_multiple')
 
   return Promise.resolve()
@@ -98,14 +115,14 @@ function doFetch (ctx, paths, dist, pkgData, keypath, log) {
     .then(_ => log('downloading'))
     .then(_ => mkdirp(paths.store))
     .then(_ => mkdirp(paths.tmp))
-    .then(_ => fetch(paths.tmp, dist.tarball, dist.shasum, log))
+    .then(_ => fetch(paths.tmp, pkg.dist.tarball, pkg.dist.shasum, log))
     .then(_ => linkBins(paths.modules, paths.tmp, paths.target))
     .then(_ => log('dependencies'))
     .then(_ => installAll(ctx,
-      pkgData.dependencies,
+      pkg.data.dependencies,
       join(paths.tmp, 'node_modules'),
-      { keypath: keypath }))
-    .then(_ => symlinkSelf(paths.tmp, pkgData, keypath.length - 1))
+      { keypath: pkg.keypath.concat([ pkg.fullname ]) }))
+    .then(_ => symlinkSelf(paths.tmp, pkg.data, pkg.keypath.length))
     .then(_ => fs.unlink(paths.target))
     .then(_ => fs.rename(paths.tmp, paths.target))
 }
@@ -154,3 +171,11 @@ function symlinkToModules (target, pkg, modules) {
 
   return relSymlink(target, join(modules, pkg.name))
 }
+
+/*
+ * Checks if the current package is a circular dependency.
+ */
+
+function isCircular (pkg) {
+  return pkg.keypath.indexOf(pkg.fullname) > -1
+}