add json ASCII string render (#1358)

add a json render that rendering json as ASCII string

render/render_test.go

@@ -167,6 +167,35 @@ func TestRenderJsonpJSONFail(t *testing.T) {
 	assert.Error(t, err)
 }
 
+func TestRenderAsciiJSON(t *testing.T) {
+	w1 := httptest.NewRecorder()
+	data1 := map[string]interface{}{
+		"lang": "GO语言",
+		"tag":  "<br>",
+	}
+
+	err := (AsciiJSON{data1}).Render(w1)
+
+	assert.NoError(t, err)
+	assert.Equal(t, "{\"lang\":\"GO\\u8bed\\u8a00\",\"tag\":\"\\u003cbr\\u003e\"}", w1.Body.String())
+	assert.Equal(t, "application/json", w1.Header().Get("Content-Type"))
+
+	w2 := httptest.NewRecorder()
+	data2 := float64(3.1415926)
+
+	err = (AsciiJSON{data2}).Render(w2)
+	assert.NoError(t, err)
+	assert.Equal(t, "3.1415926", w2.Body.String())
+}
+
+func TestRenderAsciiJSONFail(t *testing.T) {
+	w := httptest.NewRecorder()
+	data := make(chan int)
+
+	// json: unsupported type: chan int
+	assert.Error(t, (AsciiJSON{data}).Render(w))
+}
+
 type xmlmap map[string]interface{}
 
 // Allows type H to be used with xml.Marshal