behave properly when root is a symlink in build-ideal-tree

.gitignore

@@ -56,6 +56,7 @@ scripts/benchmark/*/
 /test/fixtures/selflink/node_modules/foo/node_modules/selflink
 /test/fixtures/symlinked-node-modules/example/node_modules
 /test/fixtures/symlinked-node-modules/linked-node-modules/bar
+/test/fixtures/testing-peer-deps-link
 /test/fixtures/workspace/node_modules/a
 /test/fixtures/workspace/node_modules/b
 /test/fixtures/workspace/node_modules/c

lib/arborist/build-ideal-tree.js

@@ -332,20 +332,28 @@ module.exports = cls => class IdealTreeBuilder extends cls {
       })
   }
 
-  [_globalRootNode] () {
-    const root = this[_rootNodeFromPackage]({ dependencies: {} })
+  async [_globalRootNode] () {
+    const root = await this[_rootNodeFromPackage]({ dependencies: {} })
     // this is a gross kludge to handle the fact that we don't save
     // metadata on the root node in global installs, because the "root"
     // node is something like /usr/local/lib.
     const meta = new Shrinkwrap({ path: this.path })
     meta.reset()
     root.meta = meta
-    return Promise.resolve(root)
+    return root
   }
 
-  [_rootNodeFromPackage] (pkg) {
-    return new Node({
+  async [_rootNodeFromPackage] (pkg) {
+    // if the path doesn't exist, then we explode at this point. Note that
+    // this is not a problem for reify(), since it creates the root path
+    // before ever loading trees.
+    // TODO: make buildIdealTree() and loadActual handle a missing root path,
+    // or a symlink to a missing target, and let reify() create it as needed.
+    const real = await realpath(this.path, this[_rpcache], this[_stcache])
+    const Cls = real === this.path ? Node : Link
+    const root = new Cls({
       path: this.path,
+      realpath: real,
       pkg,
       extraneous: false,
       dev: false,
@@ -355,12 +363,29 @@ module.exports = cls => class IdealTreeBuilder extends cls {
       global: this[_global],
       legacyPeerDeps: this.legacyPeerDeps,
     })
+    if (root.isLink) {
+      root.target = new Node({
+        path: real,
+        realpath: real,
+        pkg,
+        extraneous: false,
+        dev: false,
+        devOptional: false,
+        peer: false,
+        optional: false,
+        global: this[_global],
+        legacyPeerDeps: this.legacyPeerDeps,
+        root,
+      })
+    }
+    return root
   }
 
   // process the add/rm requests by modifying the root node, and the
   // update.names request by queueing nodes dependent on those named.
   async [_applyUserRequests] (options) {
     process.emit('time', 'idealTree:userRequests')
+    const tree = this.idealTree.target || this.idealTree
     // If we have a list of package names to update, and we know it's
     // going to update them wherever they are, add any paths into those
     // named nodes to the buildIdealTree queue.
@@ -373,15 +398,15 @@ module.exports = cls => class IdealTreeBuilder extends cls {
       const nm = resolve(this.path, 'node_modules')
       for (const name of await readdir(nm)) {
         if (this[_updateAll] || this[_updateNames].includes(name))
-          this.idealTree.package.dependencies[name] = '*'
+          tree.package.dependencies[name] = '*'
       }
     }
 
     if (this.auditReport && this.auditReport.size > 0)
       this[_queueVulnDependents](options)
 
     if (options.rm && options.rm.length) {
-      addRmPkgDeps.rm(this.idealTree.package, options.rm)
+      addRmPkgDeps.rm(tree.package, options.rm)
       for (const name of options.rm)
         this[_explicitRequests].add(name)
     }
@@ -391,7 +416,7 @@ module.exports = cls => class IdealTreeBuilder extends cls {
 
     // triggers a refresh of all edgesOut
     if (options.add && options.add.length || options.rm && options.rm.length)
-      this.idealTree.package = this.idealTree.package
+      tree.package = tree.package
     process.emit('timeEnd', 'idealTree:userRequests')
   }
 
@@ -410,8 +435,9 @@ module.exports = cls => class IdealTreeBuilder extends cls {
       this[_resolvedAdd] = add
       // now add is a list of spec objects with names.
       // find a home for each of them!
+      const tree = this.idealTree.target || this.idealTree
       addRmPkgDeps.add({
-        pkg: this.idealTree.package,
+        pkg: tree.package,
         add,
         saveBundle,
         saveType,
@@ -514,7 +540,7 @@ module.exports = cls => class IdealTreeBuilder extends cls {
           fixAvailable,
         } = topVuln
         for (const node of topNodes) {
-          if (node !== this.idealTree) {
+          if (node !== this.idealTree && node !== this.idealTree.target) {
             // not something we're going to fix, sorry.  have to cd into
             // that directory and fix it yourself.
             this.log.warn('audit', 'Manual fix required in linked project ' +
@@ -646,11 +672,12 @@ This is a one-time fix-up, please be patient...
   // at this point we have a virtual tree with the actual root node's
   // package deps, which may be partly or entirely incomplete, invalid
   // or extraneous.
-  [_buildDeps] (node) {
+  [_buildDeps] () {
     process.emit('time', 'idealTree:buildDeps')
-    this[_depsQueue].push(this.idealTree)
+    const tree = this.idealTree.target || this.idealTree
+    this[_depsQueue].push(tree)
     this.log.silly('idealTree', 'buildDeps')
-    this.addTracker('idealTree', this.idealTree.name, '')
+    this.addTracker('idealTree', tree.name, '')
     return this[_buildDepStep]()
       .then(() => process.emit('timeEnd', 'idealTree:buildDeps'))
   }
@@ -1137,7 +1164,8 @@ This is a one-time fix-up, please be patient...
 
       // when installing globally, or just in global style, we never place
       // deps above the first level.
-      if (this[_globalStyle] && check.resolveParent === this.idealTree)
+      const tree = this.idealTree && this.idealTree.target || this.idealTree
+      if (this[_globalStyle] && check.resolveParent === tree)
         break
     }
 

lib/arborist/reify.js

@@ -183,8 +183,9 @@ module.exports = cls => class Reifier extends cls {
     const actualOpt = this[_global] ? {
       ignoreMissing: true,
       global: true,
-      filter: (node, kid) => !node.isRoot ? true
-      : (node.edgesOut.has(kid) || this[_explicitRequests].has(kid)),
+      filter: (node, kid) => !node.isRoot && node !== node.root.target
+        ? true
+        : (node.edgesOut.has(kid) || this[_explicitRequests].has(kid)),
     } : { ignoreMissing: true }
 
     if (!this[_global]) {

lib/printable.js

@@ -80,19 +80,21 @@ const treeError = ({code, path}) => ({
 // util.inspect() output will be a bit cleaner
 class Edge {
   constructor (edge) {
-    this.from = edge.from.location
     this.type = edge.type
     this.name = edge.name
     this.spec = edge.spec || '*'
-    if (edge.to)
-      this.to = edge.to.location
     if (edge.error)
       this.error = edge.error
   }
 }
 
 // don't care about 'from' for edges out
 class EdgeOut extends Edge {
+  constructor (edge) {
+    super(edge)
+    this.to = edge.to && edge.to.location
+  }
+
   [util.inspect.custom] () {
     return `{ ${this.type} ${this.name}@${this.spec}${
       this.to ? ' -> ' + this.to : ''
@@ -104,6 +106,11 @@ class EdgeOut extends Edge {
 
 // don't care about 'to' for edges in
 class EdgeIn extends Edge {
+  constructor (edge) {
+    super(edge)
+    this.from = edge.from && edge.from.location
+  }
+
   [util.inspect.custom] () {
     return `{ ${this.from || '""'} ${this.type} ${this.name}@${this.spec}${
       this.error ? ' ' + this.error : ''