fix(post): Create a tag before makeing a release

target_commitish in GitHub Releases has two different meanings:
* Target commit that a new associated tag will be created on
* Target branch to compute how many "commits to since this release"

target_commitish is usually the default branch (aka master), because the
distance between the release and the latest branch is the primary concern.

Before this change, target_commitish was left to be a hash and the
feature of GitHub Releases that shows how much time passed since the
release is ruined, because no tracking branch is given.

By this change, target_commitish is changed to be the default branch
given in the configuration (options.branch) via edit a release API after
the release and tag are created via crate a release API.

src/post.js

@@ -24,12 +24,18 @@ module.exports = function (config, cb) {
       if (err) return cb(err)
 
       var ghRepo = parseSlug(pkg.repository.url)
+      var tag = {
+        owner: ghRepo[0],
+        repo: ghRepo[1],
+        ref: 'refs/heads/v' + pkg.version,
+        sha: hash
+      }
       var release = {
         owner: ghRepo[0],
         repo: ghRepo[1],
-        name: 'v' + pkg.version,
         tag_name: 'v' + pkg.version,
-        target_commitish: hash,
+        name: 'v' + pkg.version,
+        target_commitish: options.branch,
         draft: !!options.debug,
         body: log
       }
@@ -43,10 +49,22 @@ module.exports = function (config, cb) {
         token: options.githubToken
       })
 
-      github.repos.createRelease(release, function (err) {
+      if (options.debug) {
+        return github.repos.createRelease(release, function (err) {
+          if (err) return cb(err)
+
+          cb(null, true, release)
+        })
+      }
+
+      github.gitdata.createReference(tag, function (err) {
         if (err) return cb(err)
 
-        cb(null, true, release)
+        github.repos.createRelease(release, function (err) {
+          if (err) return cb(err)
+
+          cb(null, true, release)
+        })
       })
     })
   })

test/mocks/github.js

@@ -3,6 +3,11 @@ module.exports = function () {
     authenticate: function () {
       return true
     },
+    gitdata: {
+      createReference: function (release, cb) {
+        cb(null)
+      }
+    },
     repos: {
       createRelease: function (release, cb) {
         cb(null)

test/specs/post.js

@@ -23,14 +23,14 @@ var defaultRelease = {
   repo: 'up',
   name: 'v1.0.0',
   tag_name: 'v1.0.0',
-  target_commitish: 'bar',
+  target_commitish: 'master',
   body: 'the log'
 }
 
 test('full post run', function (t) {
   t.test('in debug mode w/o token', function (tt) {
     post({
-      options: {debug: true},
+      options: {debug: true, branch: 'master'},
       pkg: pkg,
       plugins: plugins
     }, function (err, published, release) {
@@ -44,7 +44,7 @@ test('full post run', function (t) {
 
   t.test('in debug mode w/token', function (tt) {
     post({
-      options: {debug: true, githubToken: 'yo'},
+      options: {debug: true, githubToken: 'yo', branch: 'master'},
       pkg: pkg,
       plugins: plugins
     }, function (err, published, release) {
@@ -58,7 +58,7 @@ test('full post run', function (t) {
 
   t.test('production', function (tt) {
     post({
-      options: {githubToken: 'yo'},
+      options: {githubToken: 'yo', branch: 'master'},
       pkg: pkg,
       plugins: plugins
     }, function (err, published, release) {