package chart import ( "bytes" "testing" "github.com/blendlabs/go-assert" ) func TestLegend(t *testing.T) { assert := assert.New(t) graph := Chart{ Series: []Series{ ContinuousSeries{ Name: "A test series", XValues: []float64{1.0, 2.0, 3.0, 4.0, 5.0}, YValues: []float64{1.0, 2.0, 3.0, 4.0, 5.0}, }, }, } //note we have to do this as a separate step because we need a reference to graph graph.Elements = []Renderable{ Legend(&graph), } buf := bytes.NewBuffer([]byte{}) err := graph.Render(PNG, buf) assert.Nil(err) assert.NotZero(buf.Len()) }