no omitempty for dashboard graphs and value widgets

dashboards.go

@@ -126,14 +126,27 @@ type Metric struct {
 	Query       string `json:"query,omitempty"`
 	Legend      string `json:"legend,omitempty"`
 }
+type metricQuery struct {
+	Type        string `json:"type"`
+	Name        string `json:"-"`
+	HostID      string `json:"-"`
+	ServiceName string `json:"-"`
+	Expression  string `json:"-"`
+	Query       string `json:"query"`
+	Legend      string `json:"legend"`
+}
 
 // MarshalJSON marshals as JSON
 func (m Metric) MarshalJSON() ([]byte, error) {
 	type Alias Metric
-	if m.Type == "" {
+	switch m.Type {
+	case "":
 		return []byte("null"), nil
+	case "query":
+		return json.Marshal(metricQuery(m))
+	default:
+		return json.Marshal(Alias(m))
 	}
-	return json.Marshal(Alias(m))
 }
 
 // FormatRule information
@@ -155,14 +168,29 @@ type Graph struct {
 	Query        string `json:"query,omitempty"`
 	Legend       string `json:"legend,omitempty"`
 }
+type graphQuery struct {
+	Type         string `json:"type"`
+	Name         string `json:"-"`
+	HostID       string `json:"-"`
+	RoleFullName string `json:"-"`
+	IsStacked    bool   `json:"-"`
+	ServiceName  string `json:"-"`
+	Expression   string `json:"-"`
+	Query        string `json:"query"`
+	Legend       string `json:"legend"`
+}
 
 // MarshalJSON marshals as JSON
 func (g Graph) MarshalJSON() ([]byte, error) {
 	type Alias Graph
-	if g.Type == "" {
+	switch g.Type {
+	case "":
 		return []byte("null"), nil
+	case "query":
+		return json.Marshal(graphQuery(g))
+	default:
+		return json.Marshal(Alias(g))
 	}
-	return json.Marshal(Alias(g))
 }
 
 // Range information

dashboards_test.go

@@ -549,3 +549,116 @@ func TestRangeMarshalJSON(t *testing.T) {
 		}
 	}
 }
+
+func TestMetricMarshalJSON(t *testing.T) {
+	tests := []struct {
+		m    Metric
+		want string
+	}{
+		{
+			m: Metric{
+				Type:   "host",
+				Name:   "loadavg5",
+				HostID: "0000",
+			},
+			want: `{"type":"host","name":"loadavg5","hostId":"0000"}`,
+		},
+		{
+			m: Metric{
+				Type:        "service",
+				Name:        "metric0",
+				ServiceName: "service0",
+			},
+			want: `{"type":"service","name":"metric0","serviceName":"service0"}`,
+		},
+		{
+			m: Metric{
+				Type:       "expression",
+				Expression: "max(role(my-service:db, loadavg5))",
+			},
+			want: `{"type":"expression","expression":"max(role(my-service:db, loadavg5))"}`,
+		},
+		{
+			m: Metric{
+				Type:   "query",
+				Query:  "up{}",
+				Legend: "",
+			},
+			want: `{"type":"query","query":"up{}","legend":""}`,
+		},
+		{
+			m:    Metric{},
+			want: "null",
+		},
+	}
+	for _, tt := range tests {
+		b, err := json.Marshal(tt.m)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if s := string(b); s != tt.want {
+			t.Errorf("MarshalJSON(%v) = %q; want %q", tt.m, s, tt.want)
+		}
+	}
+}
+
+func TestGraphMarshalJSON(t *testing.T) {
+	tests := []struct {
+		g    Graph
+		want string
+	}{
+		{
+			g: Graph{
+				Type:   "host",
+				Name:   "loadavg5",
+				HostID: "0000",
+			},
+			want: `{"type":"host","name":"loadavg5","hostId":"0000"}`,
+		},
+		{
+			g: Graph{
+				Type:         "role",
+				Name:         "loadavg5",
+				RoleFullName: "my-service:db",
+				IsStacked:    true,
+			},
+			want: `{"type":"role","name":"loadavg5","roleFullname":"my-service:db","isStacked":true}`,
+		},
+		{
+			g: Graph{
+				Type:        "service",
+				Name:        "my-metric",
+				ServiceName: "my-service",
+			},
+			want: `{"type":"service","name":"my-metric","serviceName":"my-service"}`,
+		},
+		{
+			g: Graph{
+				Type:       "expression",
+				Expression: "max(role(my-service:db, loadavg5))",
+			},
+			want: `{"type":"expression","expression":"max(role(my-service:db, loadavg5))"}`,
+		},
+		{
+			g: Graph{
+				Type:   "query",
+				Query:  "up{}",
+				Legend: "{{instance}}",
+			},
+			want: `{"type":"query","query":"up{}","legend":"{{instance}}"}`,
+		},
+		{
+			g:    Graph{},
+			want: "null",
+		},
+	}
+	for _, tt := range tests {
+		b, err := json.Marshal(tt.g)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if s := string(b); s != tt.want {
+			t.Errorf("MarshalJSON(%v) = %q; want %q", tt.g, s, tt.want)
+		}
+	}
+}