add spec for request_headers

lib/grape_logging/loggers/request_headers.rb

@@ -17,7 +17,6 @@ def parameters(request, _)
         { headers: headers }
       end
 
-
     end
   end
 end

spec/lib/grape_logging/loggers/request_headers_spec.rb

@@ -6,9 +6,35 @@
     OpenStruct.new(env: {HTTP_REFERER: 'http://example.com', HTTP_ACCEPT: 'text/plain'})
   end
 
+  let(:mock_request_with_unhandle_headers) do
+    OpenStruct.new(env: {
+      HTTP_REFERER: 'http://example.com',
+      "PATH_INFO"=>"/api/v1/users"
+    })
+  end
+
+  let(:mock_request_with_long_headers) do
+    OpenStruct.new(env: {
+      HTTP_REFERER: 'http://example.com',
+      HTTP_USER_AGENT: "Mozilla/5.0"
+    })
+  end
+
   it 'strips HTTP_ from the parameter' do
     expect(subject.parameters(mock_request, nil)).to eq({
       headers: {'Referer' => 'http://example.com', 'Accept' => 'text/plain'}
     })
   end
+
+  it 'only handle things which start with HTTP_' do
+    expect(subject.parameters(mock_request_with_unhandle_headers, nil)).to eq({
+      headers: {'Referer' => 'http://example.com' }
+    })
+  end
+
+  it 'substitutes _ with -' do
+    expect(subject.parameters(mock_request_with_long_headers, nil)).to eq({
+      headers: {'Referer' => 'http://example.com', 'User-Agent' => 'Mozilla/5.0' }
+    })
+  end
 end