fix validate inputs

lib/services/merge_branch_service.rb

@@ -5,9 +5,11 @@ class MergeBrachService
   TYPE_NOW = "now".freeze
 
   def self.validate_inputs!(target_branch:, type:, label_name:)
-    raise "Invalid type" if type != TYPE_LABELED || type != TYPE_NOW
-    raise "Empty target branch" if target_branch
-    raise "Empty target label name" if type == TYPE_LABELED && label_name
+    raise "Invalid type" unless [TYPE_LABELED, TYPE_NOW].include?(type)
+    raise "Empty target branch" unless target_branch
+    if type == TYPE_LABELED
+      raise "Empty target label name" unless label_name
+    end
   end
 
   def initialize(inputs, github_event)

spec/merge_brach_service_spec.rb

@@ -19,6 +19,20 @@ describe MergeBrachService do
       { type: 'labeled', target_branch: target_branch, label_name: label_name }
     }
 
+    context "with valid inputs" do
+      it ".validate_inputs!" do
+        expect{ MergeBrachService.validate_inputs!(inputs) }.to_not raise_error()
+      end
+    end
+
+    context "with invalid label name" do
+      let(:label_name) { nil }
+
+      it ".validate_inputs!" do
+        expect{ MergeBrachService.validate_inputs!(inputs) }.to raise_error()
+      end
+    end
+
     context "not match label" do
       let(:event) { { 'action' => 'labeled', 'label' => { 'name' => 'other label' } } }