feat(getLastRelease): Move getLastRelease to plugin. Remove npm tag

Move getLastRelease into it's very own plugin (@semantic-release/last-release-npm),
which this project now depends on.

BREAKING CHANGE: Remove npmTag from output of getLastRelease. It wasn't used anywhere.
Refs semantic-release#56, semantic-release#51

src/lib/last-release.js

@@ -1,26 +1,5 @@
-const SemanticReleaseError = require('@semantic-release/error')
+module.exports = function (config, cb) {
+  const {plugins} = config
 
-const npmlog = require('npmlog')
-const RegClient = require('npm-registry-client')
-
-module.exports = function ({pkg, npm}, cb) {
-  npmlog.level = npm.loglevel || 'error'
-  const client = new RegClient({log: npmlog})
-
-  client.get(`${npm.registry}${pkg.name.replace('/', '%2F')}`, {
-    auth: npm.auth
-  }, (err, data) => {
-    if (err && err.statusCode === 404) return cb(null, {})
-    if (err) return cb(err)
-
-    const version = data['dist-tags'][npm.tag]
-
-    if (!version) return cb(new SemanticReleaseError(`There is no release with the dist-tag "${npm.tag}" yet. Tag a version first.`, 'ENODISTTAG'))
-
-    cb(null, {
-      version,
-      gitHead: data.versions[version].gitHead,
-      tag: npm.tag
-    })
-  })
+  plugins.getLastRelease(config, cb)
 }

src/lib/plugins.js

@@ -5,7 +5,8 @@ let exports = module.exports = function (options) {
     analyzeCommits: exports.normalize(options.analyzeCommits, '@semantic-release/commit-analyzer'),
     generateNotes: exports.normalize(options.generateNotes, '@semantic-release/release-notes-generator'),
     verifyConditions: exports.normalize(options.verifyConditions, '@semantic-release/condition-travis'),
-    verifyRelease: exports.normalize(options.verifyRelease, './plugin-noop')
+    verifyRelease: exports.normalize(options.verifyRelease, './plugin-noop'),
+    getLastRelease: exports.normalize(options.getLastRelease, '@semantic-release/last-release-npm')
   }
 }
 

test/specs/last-release.js

@@ -1,77 +1,32 @@
-const { defaults } = require('lodash')
 const test = require('tap').test
 
-require('../mocks/registry')
 const lastRelease = require('../../dist/lib/last-release')
 
-const npm = {
-  registry: 'http://registry.npmjs.org/',
-  tag: 'latest'
-}
-
-test('last release from registry', (t) => {
-  t.plan(5)
+test('last release from plugin', (t) => {
+  t.plan(1)
 
   t.test('get release from package name', (tt) => {
-    lastRelease({
+    const config = {
       pkg: {name: 'available'},
-      npm
-    }, (err, release) => {
-      tt.error(err)
-      tt.is(release.version, '1.33.7', 'version')
-      tt.is(release.gitHead, 'HEAD', 'gitHead')
-      tt.is(release.tag, 'latest', 'dist-tag')
-
-      tt.end()
-    })
-  })
-
-  t.test('get release from a tagged package\'s name', (tt) => {
-    lastRelease({
-      pkg: {name: 'tagged'},
-      npm: defaults({tag: 'foo'}, npm)
-    }, (err, release) => {
-      tt.error(err)
-      tt.is(release.version, '0.8.15', 'version')
-      tt.is(release.gitHead, 'bar', 'gitHead')
-      tt.is(release.tag, 'foo', 'dist-tag')
-
-      tt.end()
-    })
-  })
-
-  t.test('get error from an untagged package\'s name', (tt) => {
-    lastRelease({
-      pkg: {name: 'untagged'},
-      npm: defaults({tag: 'bar'}, npm)
-    }, (err) => {
-      tt.is(err.code, 'ENODISTTAG', 'error')
-
-      tt.end()
-    })
-  })
-
-  t.test('get release from scoped package name', (tt) => {
-    lastRelease({
-      pkg: {name: '@scoped/available'},
-      npm
-    }, (err, release) => {
-      tt.error(err)
-      tt.is(release.version, '1.33.7', 'version')
+      npm: {
+        registry: 'http://registry.npmjs.org/',
+        tag: 'latest'
+      },
+      something: 'else',
+      foo: 'bar',
+      plugins: {
+        getLastRelease: (config, cb) => {
+          tt.is(config.something, 'else', 'config')
+          tt.is(config.foo, 'bar', 'config')
+          cb('pizza', { version: '1.0.0', gitHead: 'HEAD' })
+        }
+      }
+    }
+
+    lastRelease(config, (err, release) => {
+      tt.is(err, 'pizza', 'error')
+      tt.is(release.version, '1.0.0', 'version')
       tt.is(release.gitHead, 'HEAD', 'gitHead')
-      tt.is(release.tag, 'latest', 'dist-tag')
-
-      tt.end()
-    })
-  })
-
-  t.test('get nothing from not yet published package name', (tt) => {
-    lastRelease({
-      pkg: {name: 'unavailable'},
-      npm
-    }, (err, release) => {
-      tt.error(err)
-      tt.is(release.version, undefined, 'no version')
 
       tt.end()
     })

test/specs/pre.js

@@ -6,9 +6,16 @@ const pre = proxyquire('../../dist/pre', {
   'child_process': require('../mocks/child-process')
 })
 
+const versions = {
+  available: '1.0.0'
+}
+
 const plugins = {
   verifyRelease: (release, cb) => cb(null, release),
-  analyzeCommits: (commits, cb) => cb(null, 'major')
+  analyzeCommits: (commits, cb) => cb(null, 'major'),
+  getLastRelease: ({ pkg }, cb) => {
+    cb(null, { version: versions[pkg.name] || null, gitHead: 'HEAD' })
+  }
 }
 
 const npm = {