test(prefetch): Add tests for prefetch (#71)

* test(prefetch): add prefetch test

* test(prefetch): update hash algorithm to match

test/prefetch.js

@@ -1,9 +1,104 @@
 'use strict'
 
+const npmlog = require('npmlog')
+const tar = require('tar-stream')
+const crypto = require('crypto')
 const test = require('tap').test
+const tnock = require('./util/tnock')
+const cache = require('../lib/cache')
+const testDir = require('./util/test-dir')
+const CACHE = testDir(__filename)
+const prefetch = require('../prefetch')
+const mockTar = require('./util/mock-tarball')
 
-test('parses string specs into specifiers')
-test('accepts realized package specifiers')
-test('dispatches a different tarball handler based on spec type')
-test('exits early if not given `opts.cache`')
-test('exits early if `opts.digest` is already in cache')
+npmlog.level = process.env.LOGLEVEL || 'silent'
+const BASE = {
+  name: 'foo',
+  version: '1.0.0',
+  _hasShrinkwrap: false,
+  _resolved: 'https://foo.bar/x.tgz',
+  dist: {
+    tarball: 'https://foo.bar/x.tgz'
+  }
+}
+
+const OPTS = {
+  registry: 'https://mock.reg',
+  log: npmlog,
+  cache: CACHE
+}
+
+const META = {
+  name: 'foo',
+  'dist-tags': { latest: '1.2.3', lts: '1.0.0' },
+  versions: {
+    '1.0.0': BASE,
+  }
+}
+
+const PKG = {
+  'package.json': JSON.stringify({
+    name: 'foo',
+    version: '1.2.3'
+  }),
+  'index.js': 'console.log("hello world!")'
+}
+
+const SHRINKWRAP = {
+  name: 'foo',
+  version: '1.0.0'
+}
+
+test('prefetch by manifest if no digest', t => {
+  return mockTar(PKG).then(tarData => {
+    const srv = tnock(t, OPTS.registry)
+    srv.get('/foo').reply(200, META)
+    tnock(t, 'https://foo.bar').get('/x.tgz').reply(200, tarData)
+
+    return prefetch('foo@1.0.0', OPTS).then(() => {
+      t.equal(srv.isDone(), true)
+      return cache.ls(CACHE)
+    }).then(result => {
+      t.equal(Object.keys(result).length, 2)
+    })
+  })
+})
+
+test('skip if no cache is provided', t => {
+  return prefetch('foo@1.0.0', {}).then(() => {
+    return cache.ls(CACHE)
+  }).then(result => {
+    t.equal(Object.keys(result).length, 0)
+  })
+})
+
+test('use cache content if found', t => {
+  const key = cache.key('registry-request', OPTS.registry + '/foo')
+  return cache.put(CACHE, key, JSON.stringify(META), OPTS).then(digest => {
+    OPTS.digest = digest
+    OPTS.hashAlgorithm = 'sha512'
+    return prefetch('foo@1.0.0', OPTS).then(() => {
+      return cache.ls(CACHE)
+    }).then(result => {
+      t.equal(Object.keys(result).length, 1)
+    })
+  })
+})
+
+test('prefetch by manifest if digest provided but no cache content found', t => {
+  return mockTar(PKG).then(tarData => {
+    const srv = tnock(t, OPTS.registry)
+    srv.get('/foo').reply(200, META)
+
+    tnock(t, 'https://foo.bar').get('/x.tgz').reply(200, tarData)
+    const sha = crypto.createHash('sha1').update(tarData).digest('hex')
+    OPTS.digest = sha
+
+    return prefetch('foo@1.0.0', OPTS).then(() => {
+      t.equal(srv.isDone(), true)
+      return cache.ls(CACHE)
+    }).then(result => {
+      t.equal(Object.keys(result).length, 2)
+    })
+  })
+})