child-path: Compute the path of a new child module in only one place

PR-URL: //github.com//pull/9890
Fixes: #9766

lib/dedupe.js

@@ -18,6 +18,7 @@ var recalculateMetadata = require('./install/deps.js').recalculateMetadata
 var sortActions = require('./install/diff-trees.js').sortActions
 var moduleName = require('./utils/module-name.js')
 var packageId = require('./utils/package-id.js')
+var childPath = require('./utils/child-path.js')
 
 module.exports = dedupe
 module.exports.Deduper = Deduper
@@ -99,7 +100,7 @@ function move (node, hoistTo, diff) {
   node.parent.children = without(node.parent.children, node)
   hoistTo.children.push(node)
   node.fromPath = node.path
-  node.path = path.resolve(hoistTo.path, 'node_modules', moduleName(node))
+  node.path = childPath(hoistTo.path, node)
   node.parent = hoistTo
   if (!diff.filter(function (action) { return action[0] === 'move' && action[1] === node }).length) {
     diff.push(['move', node])

lib/install/inflate-bundled.js

@@ -1,15 +1,14 @@
 'use strict'
-var path = require('path')
 var validate = require('aproba')
-var moduleName = require('../utils/module-name.js')
+var childPath = require('../utils/child-path.js')
 
 module.exports = function inflateBundled (parent, children) {
   validate('OA', arguments)
   children.forEach(function (child) {
     child.fromBundle = true
     child.parent = parent
-    child.path = path.join(parent.path, moduleName(child))
-    child.realpath = path.resolve(parent.realpath, moduleName(child))
+    child.path = childPath(parent.path, child)
+    child.realpath = childPath(parent.path, child)
     child.isLink = child.isLink || parent.isLink || parent.target
     inflateBundled(child, child.children)
   })

lib/install/inflate-shrinkwrap.js

@@ -1,5 +1,4 @@
 'use strict'
-var path = require('path')
 var url = require('url')
 var asyncMap = require('slide').asyncMap
 var validate = require('aproba')
@@ -11,6 +10,7 @@ var inflateBundled = require('./inflate-bundled.js')
 var npm = require('../npm.js')
 var createChild = require('./node.js').create
 var moduleName = require('../utils/module-name.js')
+var childPath = require('../utils/child-path.js')
 
 var inflateShrinkwrap = module.exports = function (tree, swdeps, finishInflating) {
   validate('OOF', arguments)
@@ -43,8 +43,8 @@ var inflateShrinkwrap = module.exports = function (tree, swdeps, finishInflating
             loaded: false,
             parent: tree,
             fromShrinkwrap: spec,
-            path: path.join(tree.path, 'node_modules', pkg.name),
-            realpath: path.resolve(tree.realpath, 'node_modules', pkg.name),
+            path: childPath(tree.path, pkg),
+            realpath: childPath(tree.realpath, pkg),
             children: pkg._bundled || []
           })
           tree.children.push(child)

lib/utils/child-path.js

@@ -0,0 +1,10 @@
+'use strict'
+var path = require('path')
+var validate = require('aproba')
+var moduleName = require('../utils/module-name.js')
+
+module.exports = childPath
+function childPath (parentPath, child) {
+  validate('SO', arguments)
+  return path.join(parentPath, 'node_modules', moduleName(child))
+}

test/tap/unit-child-path.js

@@ -0,0 +1,9 @@
+'use strict'
+var test = require('tap').test
+var childPath = require('../../lib/utils/child-path.js')
+
+test('childPath', function (t) {
+  t.is(childPath('/path/to', {name: 'abc'}), '/path/to/node_modules/abc', 'basic use')
+  t.is(childPath('/path/to', {package: {name: '@zed/abc'}}), '/path/to/node_modules/@zed/abc', 'scoped use')
+  t.end()
+})