From b2089c6d541a2d6250f26de7793b061e517b5a9b Mon Sep 17 00:00:00 2001
From: liov <liov@maizuo.com>
Date: Thu, 17 Sep 2020 10:07:00 +0800
Subject: [PATCH] patch,tests: logic extract and unit tests

---
 patch/patcher.go     | 15 +--------------
 patch/plugin.go      | 17 ++++++++++++++++
 patch/plugin_test.go | 46 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 64 insertions(+), 14 deletions(-)
 create mode 100644 patch/plugin_test.go

diff --git a/patch/patcher.go b/patch/patcher.go
index 3d1e3f4..7311f46 100644
--- a/patch/patcher.go
+++ b/patch/patcher.go
@@ -10,7 +10,6 @@ import (
 	"go/types"
 	"log"
 	"path/filepath"
-	"reflect"
 	"regexp"
 	"strings"
 
@@ -533,19 +532,7 @@ func (p *Patcher) patchIdent(id *ast.Ident, obj types.Object) {
 				v.Tag = &ast.BasicLit{}
 			}
 
-			//tag override
-			oldTags := strings.Split(strings.TrimSpace(strings.Trim(v.Tag.Value, "` ")), " ")
-			var newTags []string
-			for _, tag := range oldTags {
-				var key string
-				if kv := strings.Split(tag, ":"); len(kv) > 0 {
-					key = kv[0]
-				}
-				if value, exist := reflect.StructTag(tags).Lookup(key); !exist || value == "" {
-					newTags = append(newTags, tag)
-				}
-			}
-			v.Tag.Value = "`" + strings.Join(append(newTags, tags), " ") + "`"
+			v.Tag.Value = "`" + mergeTags(v.Tag.Value, tags) + "`"
 			log.Printf("Add tags:\t%q.%s %s", obj.Pkg().Path(), id.Name, v.Tag.Value)
 		}
 	}
diff --git a/patch/plugin.go b/patch/plugin.go
index b38c039..867eeca 100644
--- a/patch/plugin.go
+++ b/patch/plugin.go
@@ -5,6 +5,7 @@ import (
 	"io"
 	"os"
 	"os/exec"
+	"reflect"
 	"strings"
 
 	"google.golang.org/protobuf/proto"
@@ -77,3 +78,19 @@ func Write(res *pluginpb.CodeGeneratorResponse, w io.Writer) error {
 	_, err = w.Write(out)
 	return err
 }
+
+// Override tags
+func mergeTags(oldTag, newTag string) string {
+	oldTags := strings.Split(strings.TrimSpace(strings.Trim(oldTag, "` ")), " ")
+	var newTags []string
+	for _, tag := range oldTags {
+		var key string
+		if kv := strings.Split(tag, ":"); len(kv) > 0 {
+			key = kv[0]
+		}
+		if value, exist := reflect.StructTag(newTag).Lookup(key); !exist || value == "" {
+			newTags = append(newTags, tag)
+		}
+	}
+	return strings.Join(append(newTags, newTag), " ")
+}
diff --git a/patch/plugin_test.go b/patch/plugin_test.go
new file mode 100644
index 0000000..e34e814
--- /dev/null
+++ b/patch/plugin_test.go
@@ -0,0 +1,46 @@
+package patch
+
+import (
+	"testing"
+)
+
+func TestMergeTags(t *testing.T) {
+	tests := []struct {
+		name string
+		in   [2]string
+		want string
+	}{
+		{in: [2]string{
+			`json:"code;omitempty"`,
+			`json:"-" test:"test"`,
+		},
+			want: `json:"-" test:"test"`,
+		},
+		{in: [2]string{
+			`json:"code;omitempty"`,
+			`test:"test"`,
+		},
+			want: `json:"code;omitempty" test:"test"`,
+		},
+		{in: [2]string{
+			`json:"code;omitempty"`,
+			`test1:"test1" test2:"test2"`,
+		},
+			want: `json:"code;omitempty" test1:"test1" test2:"test2"`,
+		},
+		{in: [2]string{
+			`json:"code;omitempty" test1:"test""`,
+			`test1:"test1" test2:"test2"`,
+		},
+			want: `json:"code;omitempty" test1:"test1" test2:"test2"`,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			if got := mergeTags(test.in[0], test.in[1]); got != test.want {
+				t.Fatalf(" got: %s\nwant: %s\n", got, test.want)
+			}
+		})
+	}
+}