feat(aliases): add support for registry alias specs (#147)

lib/fetch.js

@@ -40,6 +40,9 @@ function getFetcher (type) {
     // This is spelled out both to prevent sketchy stuff and to make life
     // easier for bundlers/preprocessors.
     switch (type) {
+      case 'alias':
+        fetchers[type] = require('./fetchers/alias')
+        break
       case 'directory':
         fetchers[type] = require('./fetchers/directory')
         break

lib/fetchers/alias.js

@@ -0,0 +1,20 @@
+'use strict'
+
+const Fetcher = require('../fetch')
+const fetchRegistry = require('./registry')
+
+const fetchRemote = module.exports = Object.create(null)
+
+Fetcher.impl(fetchRemote, {
+  manifest (spec, opts) {
+    return fetchRegistry.manifest(spec.subSpec, opts)
+  },
+
+  tarball (spec, opts) {
+    return fetchRegistry.tarball(spec.subSpec, opts)
+  },
+
+  fromManifest (manifest, spec, opts) {
+    return fetchRegistry.fromManifest(manifest, spec.subSpec, opts)
+  }
+})

package.json

@@ -51,7 +51,7 @@
     "mississippi": "^3.0.0",
     "mkdirp": "^0.5.1",
     "normalize-package-data": "^2.4.0",
-    "npm-package-arg": "^6.0.0",
+    "npm-package-arg": "^6.1.0",
     "npm-packlist": "^1.1.10",
     "npm-pick-manifest": "^2.1.0",
     "osenv": "^0.1.5",

test/registry.manifest.js

@@ -136,6 +136,16 @@ test('fetches manifest from registry by range', t => {
   })
 })
 
+test('fetches manifest from registry by alias', t => {
+  const srv = tnock(t, OPTS.registry)
+
+  srv.get('/foo').reply(200, META)
+  return manifest('bar@npm:foo@^1.2.0', OPTS).then(pkg => {
+    // Not 1.2.4 because 1.2.3 is `latest`
+    t.deepEqual(pkg, new Manifest(META.versions['1.2.3']), 'picked right manifest')
+  })
+})
+
 test('fetches manifest from scoped registry by range', t => {
   const srv = tnock(t, OPTS.registry)
 
@@ -145,6 +155,15 @@ test('fetches manifest from scoped registry by range', t => {
   })
 })
 
+test('fetches scoped manifest from registry by alias', t => {
+  const srv = tnock(t, OPTS.registry)
+
+  srv.get('/@usr%2ffoo').reply(200, META)
+  return manifest('bar@npm:@usr/foo@^1.2.0', OPTS).then(pkg => {
+    t.deepEqual(pkg, new Manifest(META.versions['1.2.3']), 'got scoped manifest from version')
+  })
+})
+
 test('supports opts.includeDeprecated', t => {
   const srv = tnock(t, OPTS.registry)
 

test/registry.tarball.js

@@ -61,6 +61,26 @@ test('basic tarball streaming', function (t) {
   })
 })
 
+test('aliased tarball streaming', t => {
+  const pkg = {
+    'package.json': JSON.stringify({
+      name: 'foo',
+      version: '1.2.3'
+    }),
+    'index.js': 'console.log("hello world!")'
+  }
+  return mockTar(pkg).then(tarData => {
+    const srv = tnock(t, OPTS.registry)
+    srv.get('/foo').reply(200, META(tarData))
+    srv.get('/foo/-/foo-1.2.3.tgz').reply(200, tarData)
+    return getBuff(
+      fetch.tarball(npa('bar@npm:foo@^1.2.3'), OPTS)
+    ).then(data => {
+      t.deepEqual(data, tarData, 'fetched tarball data matches')
+    })
+  })
+})
+
 test('errors if manifest fails', t => {
   const pkg = {
     'package.json': JSON.stringify({