test: add lib/link.js tests

lib/link.js

@@ -1,14 +1,18 @@
-// link with no args: symlink the folder to the global location
-// link with package arg: symlink the global to the local
+'use strict'
+
+const { readdir } = require('fs')
+const { resolve } = require('path')
+
+const Arborist = require('@npmcli/arborist')
+const npa = require('npm-package-arg')
+const rpj = require('read-package-json-fast')
+const semver = require('semver')
 
 const npm = require('./npm.js')
 const usageUtil = require('./utils/usage.js')
 const reifyOutput = require('./utils/reify-output.js')
-const { resolve } = require('path')
-const Arborist = require('@npmcli/arborist')
 
 const completion = (opts, cb) => {
-  const { readdir } = require('fs')
   const dir = npm.globalDir
   readdir(dir, (er, files) => cb(er, files.filter(f => !/^[._-]/.test(f))))
 }
@@ -23,44 +27,110 @@ const cmd = (args, cb) => link(args).then(() => cb()).catch(cb)
 
 const link = async args => {
   if (npm.config.get('global')) {
-    throw new Error(
-      'link should never be --global.\n' +
-      'Please re-run this command with --local'
+    throw Object.assign(
+      new Error(
+        'link should never be --global.\n' +
+        'Please re-run this command with --local'
+      ),
+      { code: 'ELINKGLOBAL' }
     )
   }
 
+  // link with no args: symlink the folder to the global location
+  // link with package arg: symlink the global to the local
   args = args.filter(a => resolve(a) !== npm.prefix)
-  return args.length ? linkInstall(args) : linkPkg()
+  return args.length
+    ? linkInstall(args)
+    : linkPkg()
+}
+
+// Returns a list of items that can't be fulfilled by
+// things found in the current arborist inventory
+const missingArgsFromTree = (tree, args) => {
+  const foundNodes = []
+  const missing = args.filter(a => {
+    const arg = npa(a)
+    const nodes = tree.children.values()
+    const argFound = [...nodes].every(node => {
+      // TODO: write tests for unmatching version specs, this is hard to test
+      // atm but should be simple once we have a mocked registry again
+      if (arg.name !== node.name /* istanbul ignore next */ || (
+        arg.version &&
+        !semver.satisfies(node.version, arg.version)
+      )) {
+        foundNodes.push(node)
+        return true
+      }
+    })
+    return argFound
+  })
+
+  // remote nodes from the loaded tree in order
+  // to avoid dropping them later when reifying
+  for (const node of foundNodes) {
+    node.parent = null
+  }
+
+  return missing
 }
 
 const linkInstall = async args => {
-  // add all the args as global installs, and then add symlink installs locally
-  // to the packages in the global space.
+  // load current packages from the global space,
+  // and then add symlinks installs locally
   const globalTop = resolve(npm.globalDir, '..')
-  const globalArb = new Arborist({
+  const globalOpts = {
     ...npm.flatOptions,
     path: globalTop,
-    global: true
+    global: true,
+    prune: false
+  }
+  const globalArb = new Arborist(globalOpts)
+
+  // get only current top-level packages from the global space
+  const globals = await globalArb.loadActual({
+    filter: (node, kid) =>
+      !node.isRoot || args.some(a => npa(a).name === kid)
   })
 
-  const globals = await globalArb.reify({ add: args })
+  // any extra arg that is missing from the current
+  // global space should be reified there first
+  const missing = missingArgsFromTree(globals, args)
+  if (missing.length) {
+    await globalArb.reify({
+      ...globalOpts,
+      add: missing
+    })
+  }
+
+  // get a list of module names that should be linked in the local prefix
+  const names = []
+  for (const a of args) {
+    const arg = npa(a)
+    names.push(
+      arg.type === 'directory'
+        ? (await rpj(resolve(arg.fetchSpec, 'package.json'))).name
+        : arg.name
+    )
+  }
 
-  const links = globals.edgesOut.keys()
+  // create a new arborist instance for the local prefix and
+  // reify all the pending names as symlinks there
   const localArb = new Arborist({
     ...npm.flatOptions,
     path: npm.prefix
   })
   await localArb.reify({
-    add: links.map(l => `file:${resolve(globalTop, 'node_modules', l)}`)
+    add: names.map(l => `file:${resolve(globalTop, 'node_modules', l)}`)
   })
 
   reifyOutput(localArb)
 }
 
 const linkPkg = async () => {
+  const globalTop = resolve(npm.globalDir, '..')
   const arb = new Arborist({
     ...npm.flatOptions,
-    path: resolve(npm.globalDir, '..'),
+    path: globalTop,
     global: true
   })
   await arb.reify({ add: [`file:${npm.prefix}`] })

package.json

@@ -42,7 +42,7 @@
     "./package.json": "./package.json"
   },
   "dependencies": {
-    "@npmcli/arborist": "^0.0.21",
+    "@npmcli/arborist": "^0.0.23",
     "@npmcli/ci-detect": "^1.2.0",
     "@npmcli/run-script": "^1.5.0",
     "abbrev": "~1.1.1",

tap-snapshots/test-lib-link.js-TAP.test.js

@@ -0,0 +1,25 @@
+/* IMPORTANT
+ * This snapshot file is auto-generated, but designed for humans.
+ * It should be checked into source control and tracked carefully.
+ * Re-generate by setting TAP_SNAPSHOT=1 and running tests.
+ * Make sure to inspect the output below.  Do not ignore changes!
+ */
+'use strict'
+exports[`test/lib/link.js TAP link global linked pkg to local nm when using args > should create a local symlink to global pkg 1`] = `
+{CWD}/test/lib/link-link-global-linked-pkg-to-local-nm-when-using-args/my-project/node_modules/@myscope/bar -> {CWD}/test/lib/link-link-global-linked-pkg-to-local-nm-when-using-args/global-prefix/lib/node_modules/@myscope/bar
+{CWD}/test/lib/link-link-global-linked-pkg-to-local-nm-when-using-args/my-project/node_modules/@myscope/linked -> {CWD}/test/lib/link-link-global-linked-pkg-to-local-nm-when-using-args/scoped-linked
+{CWD}/test/lib/link-link-global-linked-pkg-to-local-nm-when-using-args/my-project/node_modules/a -> {CWD}/test/lib/link-link-global-linked-pkg-to-local-nm-when-using-args/global-prefix/lib/node_modules/a
+{CWD}/test/lib/link-link-global-linked-pkg-to-local-nm-when-using-args/my-project/node_modules/link-me-too -> {CWD}/test/lib/link-link-global-linked-pkg-to-local-nm-when-using-args/link-me-too
+{CWD}/test/lib/link-link-global-linked-pkg-to-local-nm-when-using-args/my-project/node_modules/test-pkg-link -> {CWD}/test/lib/link-link-global-linked-pkg-to-local-nm-when-using-args/test-pkg-link
+
+`
+
+exports[`test/lib/link.js TAP link pkg already in global space > should create a local symlink to global pkg 1`] = `
+{CWD}/test/lib/link-link-pkg-already-in-global-space/my-project/node_modules/@myscope/linked -> {CWD}/test/lib/link-link-pkg-already-in-global-space/scoped-linked
+
+`
+
+exports[`test/lib/link.js TAP link to globalDir when in current working dir of pkg and no args > should create a global link to current pkg 1`] = `
+{CWD}/test/lib/link-link-to-globalDir-when-in-current-working-dir-of-pkg-and-no-args/global-prefix/lib/node_modules/test-pkg-link -> {CWD}/test/lib/link-link-to-globalDir-when-in-current-working-dir-of-pkg-and-no-args/test-pkg-link
+
+`