Fix assigning labels/assignees without the other

The GitHub API doesn't seem to like receiving `"assignees": null`.

Fixes #1240

commands/issue.go

@@ -366,10 +366,16 @@ func createIssue(cmd *Command, args *Args) {
 	}
 
 	params := map[string]interface{}{
-		"title":     title,
-		"body":      body,
-		"labels":    flagIssueLabels,
-		"assignees": flagIssueAssignees,
+		"title": title,
+		"body":  body,
+	}
+
+	if len(flagIssueLabels) > 0 {
+		params["labels"] = flagIssueLabels
+	}
+
+	if len(flagIssueAssignees) > 0 {
+		params["assignees"] = flagIssueAssignees
 	}
 
 	if flagIssueMilestone > 0 {

commands/pull_request.go

@@ -245,17 +245,18 @@ func pullRequest(cmd *Command, args *Args) {
 
 		pullRequestURL = pr.HtmlUrl
 
-		if len(flagPullRequestAssignees) > 0 || flagPullRequestMilestone > 0 ||
-			len(flagPullRequestLabels) > 0 {
-
-			params := map[string]interface{}{
-				"labels":    flagPullRequestLabels,
-				"assignees": flagPullRequestAssignees,
-			}
-			if flagPullRequestMilestone > 0 {
-				params["milestone"] = flagPullRequestMilestone
-			}
+		params = map[string]interface{}{}
+		if len(flagPullRequestLabels) > 0 {
+			params["labels"] = flagPullRequestLabels
+		}
+		if len(flagPullRequestAssignees) > 0 {
+			params["assignees"] = flagPullRequestAssignees
+		}
+		if flagPullRequestMilestone > 0 {
+			params["milestone"] = flagPullRequestMilestone
+		}
 
+		if len(params) > 0 {
 			err = client.UpdateIssue(baseProject, pr.Number, params)
 			utils.Check(err)
 		}

features/issue.feature

@@ -84,7 +84,7 @@ Feature: hub issue
     Given the GitHub API server:
     """
     get('/repos/github/hub/issues') {
-      assert :per_page => "100", :page => nil
+      assert :per_page => "100", :page => :no
       response.headers["Link"] = %(<https://api.github.com/repositories/12345?per_page=100&page=2>; rel="next")
       json [
         { :number => 102,
@@ -197,7 +197,7 @@ Feature: hub issue
       post('/repos/github/hub/issues') {
         assert :title => "Not workie, pls fix",
                :body => "",
-               :labels => nil
+               :labels => :no
 
         status 201
         json :html_url => "https://github.com/github/hub/issues/1337"
@@ -227,8 +227,8 @@ Feature: hub issue
       post('/repos/github/hub/issues') {
         assert :title => "hello",
                :body => "",
-               :milestone => nil,
-               :assignees => nil,
+               :milestone => :no,
+               :assignees => :no,
                :labels => ["wont fix", "docs", "nope"]
 
         status 201
@@ -249,7 +249,7 @@ Feature: hub issue
                :body => "",
                :milestone => 12,
                :assignees => ["mislav", "josh", "pcorpet"],
-               :labels => nil
+               :labels => :no
 
         status 201
         json :html_url => "https://github.com/github/hub/issues/1337"

features/pull_request.feature

@@ -695,7 +695,7 @@ BODY
         json :html_url => "the://url", :number => 1234
       }
       patch('/repos/mislav/coral/issues/1234') {
-        assert :assignees => ["mislav", "josh", "pcorpet"], :labels => nil
+        assert :assignees => ["mislav", "josh", "pcorpet"], :labels => :no
         json :html_url => "the://url"
       }
       """
@@ -729,7 +729,7 @@ BODY
         json :html_url => "the://url", :number => 1234
       }
       patch('/repos/mislav/coral/issues/1234') {
-        assert :labels => ["feature", "release", "docs"]
+        assert :labels => ["feature", "release", "docs"], :assignees => :no
         json :html_url => "the://url"
       }
       """

features/support/local_server.rb

@@ -69,7 +69,14 @@ module Hub
 
         def assert(expected)
           expected.each do |key, value|
-            if params[key] != value
+            if :no == value
+              halt 422, json(
+                :message => "expected %s not to be passed; got %s" % [
+                  key.inspect,
+                  params[key].inspect
+                ]
+              ) if params.key?(key.to_s)
+            elsif params[key] != value
               halt 422, json(
                 :message => "expected %s to be %s; got %s" % [
                   key.inspect,