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

3 files changed, 183 insertions, 0 deletions

diff --git a/workspaces/arborist/test/arborist/reify.js b/workspaces/arborist/test/arborist/reify.js
index 9124b4630..813c984ce 100644
--- a/workspaces/arborist/test/arborist/reify.js
+++ b/workspaces/arborist/test/arborist/reify.js
@@ -2652,3 +2652,168 @@ t.test('save package.json on update', t => {
   })
   t.end()
 })
+
+t.test('installLinks', (t) => {
+  t.test('when true, packs and extracts instead of symlinks', async (t) => {
+    const path = t.testdir({
+      a: {
+        'package.json': JSON.stringify({
+          name: 'a',
+          version: '1.0.0',
+          main: 'index.js',
+          dependencies: {
+            b: 'file:../b',
+          },
+        }),
+        'index.js': '',
+      },
+      b: {
+        'package.json': JSON.stringify({
+          name: 'b',
+          version: '1.0.0',
+          main: 'index.js',
+        }),
+        'index.js': '',
+      },
+    })
+
+    await reify(resolve(path, 'a'), { installLinks: true })
+
+    const installedB = fs.lstatSync(resolve(path, 'a/node_modules/b'))
+    t.ok(installedB.isDirectory(), 'a/node_modules/b is a directory')
+  })
+
+  t.test('when false, symlinks', async (t) => {
+    const path = t.testdir({
+      a: {
+        'package.json': JSON.stringify({
+          name: 'a',
+          version: '1.0.0',
+          main: 'index.js',
+          dependencies: {
+            b: 'file:../b',
+          },
+        }),
+        'index.js': '',
+      },
+      b: {
+        'package.json': JSON.stringify({
+          name: 'b',
+          version: '1.0.0',
+          main: 'index.js',
+        }),
+        'index.js': '',
+      },
+    })
+
+    await reify(resolve(path, 'a'), { installLinks: false })
+
+    const installedB = fs.lstatSync(resolve(path, 'a/node_modules/b'))
+    t.ok(installedB.isSymbolicLink(), 'a/node_modules/b is a symlink')
+  })
+
+  t.test('when symlinks exist, installLinks set to true replaces them with dirs', async (t) => {
+    const path = t.testdir({
+      a: {
+        'package.json': JSON.stringify({
+          name: 'a',
+          version: '1.0.0',
+          main: 'index.js',
+          dependencies: {
+            b: 'file:../b',
+          },
+        }),
+        'index.js': '',
+      },
+      b: {
+        'package.json': JSON.stringify({
+          name: 'b',
+          version: '1.0.0',
+          main: 'index.js',
+        }),
+        'index.js': '',
+      },
+    })
+
+    await reify(resolve(path, 'a'), { installLinks: false, save: true })
+
+    const firstB = fs.lstatSync(resolve(path, 'a/node_modules/b'))
+    t.ok(firstB.isSymbolicLink(), 'a/node_modules/b is a symlink')
+
+    await reify(resolve(path, 'a'), { installLinks: true, save: true })
+
+    const secondB = fs.lstatSync(resolve(path, 'a/node_modules/b'))
+    t.ok(secondB.isDirectory(), 'a/node_modules/b is now a directory')
+  })
+
+  t.test('when directories exist, installLinks set to false replaces them with symlinks', async (t) => {
+    const path = t.testdir({
+      a: {
+        'package.json': JSON.stringify({
+          name: 'a',
+          version: '1.0.0',
+          main: 'index.js',
+          dependencies: {
+            b: 'file:../b',
+          },
+        }),
+        'index.js': '',
+      },
+      b: {
+        'package.json': JSON.stringify({
+          name: 'b',
+          version: '1.0.0',
+          main: 'index.js',
+        }),
+        'index.js': '',
+      },
+    })
+
+    await reify(resolve(path, 'a'), { installLinks: true })
+
+    const firstB = fs.lstatSync(resolve(path, 'a/node_modules/b'))
+    t.ok(firstB.isDirectory(), 'a/node_modules/b is a directory')
+
+    await reify(resolve(path, 'a'), { installLinks: false })
+
+    const secondB = fs.lstatSync(resolve(path, 'a/node_modules/b'))
+    t.ok(secondB.isSymbolicLink(), 'a/node_modules/b is now a symlink')
+  })
+
+  t.test('when installLinks is true, dependencies of links are installed', async (t) => {
+    const path = t.testdir({
+      a: {
+        'package.json': JSON.stringify({
+          name: 'a',
+          version: '1.0.0',
+          main: 'index.js',
+          dependencies: {
+            b: 'file:../b',
+          },
+        }),
+        'index.js': '',
+      },
+      b: {
+        'package.json': JSON.stringify({
+          name: 'b',
+          version: '1.0.0',
+          main: 'index.js',
+          dependencies: {
+            abbrev: '^1.0.0',
+          },
+        }),
+        'index.js': '',
+      },
+    })
+
+    await reify(resolve(path, 'a'), { installLinks: true })
+
+    const installedB = fs.lstatSync(resolve(path, 'a/node_modules/b'))
+    t.ok(installedB.isDirectory(), 'a/node_modules/b is a directory')
+
+    const abbrev = fs.lstatSync(resolve(path, 'a/node_modules/abbrev'))
+    t.ok(abbrev.isDirectory(), 'abbrev got installed')
+  })
+
+  t.end()
+})
diff --git a/workspaces/arborist/test/dep-valid.js b/workspaces/arborist/test/dep-valid.js
index 3294ea4e8..901325b23 100644
--- a/workspaces/arborist/test/dep-valid.js
+++ b/workspaces/arborist/test/dep-valid.js
@@ -176,3 +176,11 @@ t.test('invalid request all together', t => {
   }, 'parent got an error for their invalid request')
   t.end()
 })
+
+t.test('installLinks makes Link nodes invalid', t => {
+  const requestor = { errors: [], installLinks: true }
+  const child = { isLink: true, name: 'kid' }
+  const request = { type: 'directory' }
+  t.notOk(depValid(child, request, null, requestor))
+  t.end()
+})
diff --git a/workspaces/arborist/test/node.js b/workspaces/arborist/test/node.js
index 80bc21559..73e081893 100644
--- a/workspaces/arborist/test/node.js
+++ b/workspaces/arborist/test/node.js
@@ -328,6 +328,16 @@ t.test('testing with dep tree', t => {
       t.equal(prodLink.children.size, 0, 'links do not have child nodes')
       t.equal(prodLink.target.children.size, kidCount, 'link target has children')
 
+      t.equal(newProd.canReplace(prodLink), true, 'node can replace link')
+      const { target } = prodLink
+      newProd.replace(prodLink)
+      t.equal(prodLink.parent, null, 'prodLink removed from tree')
+      t.equal(prodLink.target, null, 'prodLink lost its target')
+      t.equal(prodLink.root, prodLink, 'prodLink removed from tree')
+      t.equal(target.root, target, 'prodLinks old target removed from tree')
+      t.equal(normalizePath(newProd.path), normalizePath(prodLink.path), 'replaced node')
+      t.equal(prodLink.children.size, 0, 'prodLink has no child nodes')
+
       t.end()
     })