Copy the index_header partial when generating views to customize

The index_header contains the search bar and the
New resource button, which may need to be customized.
Currently this file is not created as part of the
generated customized view files, so it must
be created manually.

lib/generators/administrate/views/index_generator.rb

@@ -9,6 +9,7 @@ class IndexGenerator < Administrate::ViewGenerator
         def copy_template
           copy_resource_template("index")
           copy_resource_template("_collection")
+          copy_resource_template("_index_header")
         end
       end
     end

spec/generators/views/index_generator_spec.rb

@@ -21,6 +21,16 @@
 
       expect(contents).to eq(expected_contents)
     end
+
+    it "copies the index_header partial into the `admin/application` namespace" do
+      expected_contents = contents_for_application_template("_index_header")
+      generated_file = file("app/views/admin/application/_index_header.html.erb")
+
+      run_generator []
+      contents = File.read(generated_file)
+
+      expect(contents).to eq(expected_contents)
+    end
   end
 
   describe "administrate:views:index resource" do
@@ -41,6 +51,15 @@
 
       expect(contents).to eq(expected_contents)
     end
+
+    it "copies the index_header partial into the `admin/resource` namespace" do
+      expected_contents = contents_for_application_template("_index_header")
+
+      run_generator ["users"]
+      contents = File.read(file("app/views/admin/users/_index_header.html.erb"))
+
+      expect(contents).to eq(expected_contents)
+    end
   end
 
   describe "administrate:views:index resource --namespace=<namespace>" do
@@ -61,5 +80,14 @@
 
       expect(contents).to eq(expected_contents)
     end
+
+    it "copies the index_header partial into the `namespace/resource` namespace" do
+      expected_contents = contents_for_application_template("_index_header")
+
+      run_generator ["users", "--namespace", "console"]
+      contents = File.read(file("app/views/console/users/_index_header.html.erb"))
+
+      expect(contents).to eq(expected_contents)
+    end
   end
 end