feat(arborist): add support for installLinks

when set, installLinks instructs arborist to pack and extract a file:
dependency rather than creating a symlink to it. this has the effect of
also installing the dependencies for the linked dependency, though if
local changes are made it also requires the user to reinstall the
package

workspaces/arborist/lib/arborist/build-ideal-tree.js

@@ -124,6 +124,7 @@ module.exports = cls => class IdealTreeBuilder extends cls {
       globalStyle = false,
       idealTree = null,
       includeWorkspaceRoot = false,
+      installLinks = false,
       legacyPeerDeps = false,
       packageLock = true,
       strictPeerDeps = false,
@@ -135,6 +136,7 @@ module.exports = cls => class IdealTreeBuilder extends cls {
     this[_strictPeerDeps] = !!strictPeerDeps
 
     this.idealTree = idealTree
+    this.installLinks = installLinks
     this.legacyPeerDeps = legacyPeerDeps
 
     this[_usePackageLock] = packageLock
@@ -410,6 +412,7 @@ Try using the package name instead, e.g:
       peer: false,
       optional: false,
       global: this[_global],
+      installLinks: this.installLinks,
       legacyPeerDeps: this.legacyPeerDeps,
       loadOverrides: true,
     })
@@ -424,6 +427,7 @@ Try using the package name instead, e.g:
         peer: false,
         optional: false,
         global: this[_global],
+        installLinks: this.installLinks,
         legacyPeerDeps: this.legacyPeerDeps,
         root,
       })
@@ -992,6 +996,7 @@ This is a one-time fix-up, please be patient...
         preferDedupe: this[_preferDedupe],
         legacyBundling: this[_legacyBundling],
         strictPeerDeps: this[_strictPeerDeps],
+        installLinks: this.installLinks,
         legacyPeerDeps: this.legacyPeerDeps,
         globalStyle: this[_globalStyle],
       }))
@@ -1151,6 +1156,7 @@ This is a one-time fix-up, please be patient...
     const vr = new Node({
       path: node.realpath,
       sourceReference: node,
+      installLinks: this.installLinks,
       legacyPeerDeps: this.legacyPeerDeps,
       overrides: node.overrides,
     })
@@ -1268,17 +1274,18 @@ This is a one-time fix-up, please be patient...
     // the object so it doesn't get mutated.
     // Don't bother to load the manifest for link deps, because the target
     // might be within another package that doesn't exist yet.
-    const { legacyPeerDeps } = this
+    const { installLinks, legacyPeerDeps } = this
+    const isWorkspace = this.idealTree.workspaces && this.idealTree.workspaces.has(spec.name)
 
-    // spec is a directory, link it
-    if (spec.type === 'directory') {
+    // spec is a directory, link it unless installLinks is set or it's a workspace
+    if (spec.type === 'directory' && (isWorkspace || !installLinks)) {
       return this[_linkFromSpec](name, spec, parent, edge)
     }
 
     // if the spec matches a workspace name, then see if the workspace node will
     // satisfy the edge. if it does, we return the workspace node to make sure it
     // takes priority.
-    if (this.idealTree.workspaces && this.idealTree.workspaces.has(spec.name)) {
+    if (isWorkspace) {
       const existingNode = this.idealTree.edgesOut.get(spec.name).to
       if (existingNode && existingNode.isWorkspace && existingNode.satisfies(edge)) {
         return edge.to
@@ -1288,7 +1295,7 @@ This is a one-time fix-up, please be patient...
     // spec isn't a directory, and either isn't a workspace or the workspace we have
     // doesn't satisfy the edge. try to fetch a manifest and build a node from that.
     return this[_fetchManifest](spec)
-      .then(pkg => new Node({ name, pkg, parent, legacyPeerDeps }), error => {
+      .then(pkg => new Node({ name, pkg, parent, installLinks, legacyPeerDeps }), error => {
         error.requiredBy = edge.from.location || '.'
 
         // failed to load the spec, either because of enotarget or
@@ -1298,6 +1305,7 @@ This is a one-time fix-up, please be patient...
           name,
           parent,
           error,
+          installLinks,
           legacyPeerDeps,
         })
         this[_loadFailures].add(n)
@@ -1307,9 +1315,9 @@ This is a one-time fix-up, please be patient...
 
   [_linkFromSpec] (name, spec, parent, edge) {
     const realpath = spec.fetchSpec
-    const { legacyPeerDeps } = this
+    const { installLinks, legacyPeerDeps } = this
     return rpj(realpath + '/package.json').catch(() => ({})).then(pkg => {
-      const link = new Link({ name, parent, realpath, pkg, legacyPeerDeps })
+      const link = new Link({ name, parent, realpath, pkg, installLinks, legacyPeerDeps })
       this[_linkNodes].add(link)
       return link
     })

workspaces/arborist/lib/arborist/load-actual.js

@@ -283,6 +283,7 @@ module.exports = cls => class ActualLoader extends cls {
       .then(pkg => [pkg, null], error => [null, error])
       .then(([pkg, error]) => {
         return this[normalize(path) === real ? _newNode : _newLink]({
+          installLinks: this.installLinks,
           legacyPeerDeps: this.legacyPeerDeps,
           path,
           realpath: real,

workspaces/arborist/lib/arborist/load-virtual.js

@@ -278,6 +278,7 @@ module.exports = cls => class VirtualLoader extends cls {
     const peer = sw.peer
 
     const node = new Node({
+      installLinks: this.installLinks,
       legacyPeerDeps: this.legacyPeerDeps,
       root: this.virtualTree,
       path,
@@ -304,6 +305,7 @@ module.exports = cls => class VirtualLoader extends cls {
   [loadLink] (location, targetLoc, target, meta) {
     const path = resolve(this.path, location)
     const link = new Link({
+      installLinks: this.installLinks,
       legacyPeerDeps: this.legacyPeerDeps,
       path,
       realpath: resolve(this.path, targetLoc),

workspaces/arborist/lib/dep-valid.js

@@ -53,9 +53,7 @@ const depValid = (child, requested, requestor) => {
       return semver.satisfies(child.version, requested.fetchSpec, true)
 
     case 'directory':
-      // directory must be a link to the specified folder
-      return !!child.isLink &&
-        relative(child.realpath, requested.fetchSpec) === ''
+      return linkValid(child, requested, requestor)
 
     case 'file':
       return tarballValid(child, requested, requestor)
@@ -108,6 +106,18 @@ const depValid = (child, requested, requestor) => {
   return false
 }
 
+const linkValid = (child, requested, requestor) => {
+  const isLink = !!child.isLink
+  // if we're installing links and the node is a link, then it's invalid because we want
+  // a real node to be there
+  if (requestor.installLinks) {
+    return !isLink
+  }
+
+  // directory must be a link to the specified folder
+  return isLink && relative(child.realpath, requested.fetchSpec) === ''
+}
+
 const tarballValid = (child, requested, requestor) => {
   if (child.isLink) {
     return false

workspaces/arborist/lib/node.js

@@ -86,6 +86,7 @@ class Node {
       name,
       children,
       fsChildren,
+      installLinks = false,
       legacyPeerDeps = false,
       linksIn,
       hasShrinkwrap,
@@ -152,6 +153,7 @@ class Node {
     }
     this.integrity = integrity || pkg._integrity || null
     this.hasShrinkwrap = hasShrinkwrap || pkg._hasShrinkwrap || false
+    this.installLinks = installLinks
     this.legacyPeerDeps = legacyPeerDeps
 
     this.children = new CaseInsensitiveMap()

workspaces/arborist/lib/place-dep.js

@@ -45,6 +45,7 @@ class PlaceDep {
       auditReport,
       legacyBundling,
       strictPeerDeps,
+      installLinks,
       legacyPeerDeps,
       globalStyle,
     } = parent || options
@@ -56,6 +57,7 @@ class PlaceDep {
       auditReport,
       legacyBundling,
       strictPeerDeps,
+      installLinks,
       legacyPeerDeps,
       globalStyle,
     })
@@ -293,6 +295,7 @@ class PlaceDep {
       pkg: dep.package,
       resolved: dep.resolved,
       integrity: dep.integrity,
+      installLinks: this.installLinks,
       legacyPeerDeps: this.legacyPeerDeps,
       error: dep.errors[0],
       ...(dep.overrides ? { overrides: dep.overrides } : {}),

workspaces/arborist/tap-snapshots/test/link.js.test.cjs

@@ -16,6 +16,7 @@ Link {
   "extraneous": true,
   "fsChildren": Set {},
   "hasShrinkwrap": false,
+  "installLinks": false,
   "integrity": null,
   "inventory": Inventory {},
   "legacyPeerDeps": false,
@@ -42,6 +43,7 @@ exports[`test/link.js TAP > instantiate without providing target 1`] = `
   "extraneous": true,
   "fsChildren": Set {},
   "hasShrinkwrap": false,
+  "installLinks": false,
   "integrity": null,
   "inventory": Inventory {
     "../../../../../some/other/path" => <*ref_1>,
@@ -56,6 +58,7 @@ exports[`test/link.js TAP > instantiate without providing target 1`] = `
       "extraneous": true,
       "fsChildren": Set {},
       "hasShrinkwrap": false,
+      "installLinks": false,
       "integrity": null,
       "inventory": Inventory {},
       "legacyPeerDeps": false,
@@ -94,6 +97,7 @@ exports[`test/link.js TAP > instantiate without providing target 1`] = `
       "extraneous": true,
       "fsChildren": Set {},
       "hasShrinkwrap": false,
+      "installLinks": false,
       "integrity": null,
       "inventory": Inventory {},
       "legacyPeerDeps": false,