feat(type): Add support for rskip

Add support for rskip release type, and skipping releases.
Skipping releases is supported by semantic-release/commit-analyzer#2.

Fixes semantic-release#41

Author: ariporad

src/lib/type.js

@@ -1,4 +1,4 @@
-// TODO: Test, update commit-analyzer
+// TODO: Test
 const SemanticReleaseError = require('@semantic-release/error')
 const _ = require('lodash')
 
@@ -15,6 +15,13 @@ module.exports = function (config, cb) {
       ))
     }
 
+    if (type === 'rskip') {
+      return cb(new SemanticReleaseError(
+          'The release was skipped',
+          'ERELSKIP'
+        ))
+    }
+
     if (!lastRelease.version) return cb(null, 'initial')
 
     cb(null, type)
@@ -34,6 +41,8 @@ function parseCommits (parse, config, commits, cb) {
       if (type < t) type = t
 
       if (i === 0) {
+        if (t === 'rskip') return cb(null, t)
+
         let out = types[type]
         if (out === types[0]) out = false
         return cb(null, out)

test/specs/type.js

@@ -3,7 +3,7 @@ const test = require('tap').test
 const type = require('../../dist/lib/type')
 
 test('get type from commits', (t) => {
-  t.plan(4)
+  t.plan(5)
 
   t.test('get type from plugin', (tt) => {
     tt.plan(2)
@@ -78,5 +78,17 @@ test('get type from commits', (t) => {
     })
   })
 
+  t.test('error when skipped', (tt) => {
+    tt.plan(1)
+
+    type({
+      commits: [],
+      lastRelease: {},
+      plugins: {analyzeCommits: (config, cb) => cb(null, 'rskip')}
+    }, (err) => {
+      tt.is(err.code, 'ERELSKIP')
+    })
+  })
+
   t.end()
 })