add a name generator util func to replace fmt.Sprintf

schema/naming.go

@@ -53,25 +53,23 @@ func (ns NamingStrategy) JoinTableName(str string) string {
 
 // RelationshipFKName generate fk name for relation
 func (ns NamingStrategy) RelationshipFKName(rel Relationship) string {
-	return strings.Replace(fmt.Sprintf("fk_%s_%s", rel.Schema.Table, toDBName(rel.Name)), ".", "_", -1)
+	return genPatternName("fk", charUnderscore, charPoint, rel.Schema.Table, toDBName(rel.Name))
 }
 
 // CheckerName generate checker name
 func (ns NamingStrategy) CheckerName(table, column string) string {
-	return strings.Replace(fmt.Sprintf("chk_%s_%s", table, column), ".", "_", -1)
+	return genPatternName("chk", charUnderscore, charPoint, table, toDBName(column))
 }
 
 // IndexName generate index name
 func (ns NamingStrategy) IndexName(table, column string) string {
-	idxName := fmt.Sprintf("idx_%v_%v", table, toDBName(column))
-	idxName = strings.Replace(idxName, ".", "_", -1)
-
+	idxName := genPatternName("idx", charUnderscore, charPoint, table, toDBName(column))
 	if utf8.RuneCountInString(idxName) > 64 {
 		h := sha1.New()
 		h.Write([]byte(idxName))
 		bs := h.Sum(nil)
 
-		idxName = fmt.Sprintf("idx%v%v", table, column)[0:56] + string(bs)[:8]
+		idxName = genPatternName("idx", charBlank, charBlank, table, column)[0:56] + string(bs)[:8]
 	}
 	return idxName
 }

schema/utils.go

@@ -195,3 +195,24 @@ type embeddedNamer struct {
 	Table string
 	Namer
 }
+
+var (
+	charBlank      = ""
+	charPoint      = "."
+	charUnderscore = "_"
+)
+
+// genPatternName generate pattern string, use to replace fmt.Sprintf()
+func genPatternName(prefix, intervalBefore, intervalAfter string, vars ...string) string {
+	for i := range vars {
+		if intervalBefore != charBlank {
+			prefix += intervalBefore + vars[i]
+			continue
+		}
+		prefix += vars[i]
+	}
+	if intervalAfter == charBlank {
+		return prefix
+	}
+	return strings.Replace(prefix, intervalAfter, intervalBefore, -1)
+}

schema/utils_test.go

@@ -22,3 +22,48 @@ func TestRemoveSettingFromTag(t *testing.T) {
 		}
 	}
 }
+
+func TestGenPatternName(t *testing.T) {
+	gives := []struct {
+		Prefix         string
+		IntervalBefore string
+		IntervalAfter  string
+		Vars           []string
+		Want           string
+	}{
+		{
+			Prefix:         "fk",
+			IntervalBefore: charUnderscore,
+			IntervalAfter:  charPoint,
+			Vars:           []string{"a", "b"},
+			Want:           "fk_a_b",
+		},
+		{
+			Prefix:         "idx",
+			IntervalBefore: charUnderscore,
+			IntervalAfter:  charPoint,
+			Vars:           []string{"a", "b"},
+			Want:           "idx_a_b",
+		},
+		{
+			Prefix:         "chk",
+			IntervalBefore: charUnderscore,
+			IntervalAfter:  charPoint,
+			Vars:           []string{"a", "b"},
+			Want:           "chk_a_b",
+		},
+		{
+			Prefix:         "idx",
+			IntervalBefore: charBlank,
+			IntervalAfter:  charBlank,
+			Vars:           []string{"a", "b"},
+			Want:           "idxab",
+		},
+	}
+
+	for i := range gives {
+		if genPatternName(gives[i].Prefix, gives[i].IntervalBefore, gives[i].IntervalAfter, gives[i].Vars...) != gives[i].Want {
+			t.Errorf("want %s, but got %s", gives[i].Want, genPatternName(gives[i].Prefix, gives[i].IntervalBefore, gives[i].IntervalAfter, gives[i].Vars...))
+		}
+	}
+}