coal: clarified item base embedding rules

Author: 256dpi

coal/meta.go

@@ -430,11 +430,24 @@ func GetItemMeta(typ reflect.Type) *ItemMeta {
 	}
 
 	// check if embedding item
-	if typ.NumField() == 0 || typ.Field(0).Type != itemBaseType || !typ.Field(0).Anonymous {
+	if typ.NumField() == 0 || typ.Field(0).Type != itemBaseType {
 		return nil
 	}
 
-	// TODO: Validate json and bson tags.
+	// check if field is anonymous
+	if !typ.Field(0).Anonymous {
+		panic(`coal: expected an embedded "coal.ItemBase" as the first struct field`)
+	}
+
+	// check JSON tag
+	if typ.Field(0).Tag.Get("json") != "" && typ.Field(0).Tag.Get("json") != "-" {
+		panic(`coal: expected to find no tag or a tag of the form 'json:"-"' on "coal.ItemBase"`)
+	}
+
+	// check BSON tag
+	if typ.Field(0).Tag.Get("bson") != ",inline" && typ.Field(0).Tag.Get("bson") != "-" {
+		panic(`coal: expected to find a tag of the form 'bson:",inline" or 'bson:"-" on "coal.ItemBase"`)
+	}
 
 	// prepare meta
 	meta = &ItemMeta{

coal/model_test.go

@@ -60,6 +60,21 @@ func TestList(t *testing.T) {
 	list[1].ItemID = "b"
 
 	var out []stick.Map
+	err = stick.BSON.Transfer(list, &out)
+	assert.NoError(t, err)
+	assert.Equal(t, []stick.Map{
+		{
+			"_id":   "a",
+			"title": "Foo",
+			"done":  false,
+		}, {
+			"_id":   "b",
+			"title": "Bar",
+			"done":  true,
+		},
+	}, out)
+
+	out = nil
 	err = stick.JSON.Transfer(list, &out)
 	assert.NoError(t, err)
 	assert.Equal(t, []stick.Map{
@@ -74,6 +89,8 @@ func TestList(t *testing.T) {
 		},
 	}, out)
 
+	/* move items */
+
 	out[0], out[1] = out[1], out[0]
 	out = append(out, stick.Map{
 		"id":    "c",

coal/utils_test.go

@@ -59,9 +59,9 @@ func (m *noteModel) Validate() error {
 }
 
 type listItem struct {
-	ItemBase
-	Title string `json:"title"`
-	Done  bool   `json:"done"`
+	ItemBase `bson:",inline"`
+	Title    string `json:"title"`
+	Done     bool   `json:"done"`
 }
 
 func (i *listItem) Validate() error {