add flag clear_tag_comment to clear the tag comment

README.md

@@ -37,6 +37,8 @@ Usage of protoc-go-inject-tag:
         pattern to match input file(s)
   -verbose
         verbose logging
+  -clear_tag_comment
+        clear tag comment
 ```
 
 Add a comment with the following syntax before fields, and these will be
@@ -102,3 +104,4 @@ Since **v1.3.0**, we recommend using `@gotags:` rather than `@inject_tags:`,
 as `@gotags` is more indicative of the language the comment is for. We don't
 plan on removing `@inject_tags:` support anytime soon, however we strongly
 recommend switching to `@gotags`.
+

file.go

@@ -15,13 +15,16 @@ var (
 	rComment = regexp.MustCompile(`^//.*?@(?i:gotags?|inject_tags?):\s*(.*)$`)
 	rInject  = regexp.MustCompile("`.+`$")
 	rTags    = regexp.MustCompile(`[\w_]+:"[^"]+"`)
+	rAll     = regexp.MustCompile(".*")
 )
 
 type textArea struct {
-	Start      int
-	End        int
-	CurrentTag string
-	InjectTag  string
+	Start        int
+	End          int
+	CurrentTag   string
+	InjectTag    string
+	CommentStart int
+	CommentEnd   int
 }
 
 func parseFile(inputPath string, xxxSkip []string) (areas []textArea, err error) {
@@ -112,10 +115,12 @@ func parseFile(inputPath string, xxxSkip []string) (areas []textArea, err error)
 
 				currentTag := field.Tag.Value
 				area := textArea{
-					Start:      int(field.Pos()),
-					End:        int(field.End()),
-					CurrentTag: currentTag[1 : len(currentTag)-1],
-					InjectTag:  tag,
+					Start:        int(field.Pos()),
+					End:          int(field.End()),
+					CurrentTag:   currentTag[1 : len(currentTag)-1],
+					InjectTag:    tag,
+					CommentStart: int(comment.Pos()),
+					CommentEnd:   int(comment.End()),
 				}
 				areas = append(areas, area)
 			}
@@ -125,7 +130,7 @@ func parseFile(inputPath string, xxxSkip []string) (areas []textArea, err error)
 	return
 }
 
-func writeFile(inputPath string, areas []textArea) (err error) {
+func writeFile(inputPath string, areas []textArea, clearTagCommon bool) (err error) {
 	f, err := os.Open(inputPath)
 	if err != nil {
 		return
@@ -144,7 +149,7 @@ func writeFile(inputPath string, areas []textArea) (err error) {
 	for i := range areas {
 		area := areas[len(areas)-i-1]
 		logf("inject custom tag %q to expression %q", area.InjectTag, string(contents[area.Start-1:area.End-1]))
-		contents = injectTag(contents, area)
+		contents = injectTag(contents, area, clearTagCommon)
 	}
 	if err = ioutil.WriteFile(inputPath, contents, 0644); err != nil {
 		return

main.go

@@ -10,9 +10,12 @@ import (
 
 func main() {
 	var inputFiles, xxxTags string
+	var clearTagCommon bool
 	flag.StringVar(&inputFiles, "input", "", "pattern to match input file(s)")
 	flag.StringVar(&xxxTags, "XXX_skip", "", "tags that should be skipped (applies 'tag:\"-\"') for unknown fields (deprecated since protoc-gen-go v1.4.0)")
+	flag.BoolVar(&clearTagCommon, "clear_tag_comment", false, "clear tag comment")
 	flag.BoolVar(&verbose, "verbose", false, "verbose logging")
+
 	flag.Parse()
 
 	var xxxSkipSlice []string
@@ -54,7 +57,7 @@ func main() {
 		if err != nil {
 			log.Fatal(err)
 		}
-		if err = writeFile(path, areas); err != nil {
+		if err = writeFile(path, areas, clearTagCommon); err != nil {
 			log.Fatal(err)
 		}
 	}

main_test.go

@@ -61,7 +61,64 @@ func TestParseWriteFile(t *testing.T) {
 	}
 	defer os.Remove(testInputFileTemp)
 
-	if err = writeFile(testInputFileTemp, areas); err != nil {
+	if err = writeFile(testInputFileTemp, areas, false); err != nil {
+		t.Fatal(err)
+	}
+
+	newAreas, err := parseFile(testInputFileTemp, []string{})
+	if len(newAreas) != len(areas) {
+		t.Errorf("the comment tag has error")
+	}
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// check if file contains custom tag
+	contents, err = ioutil.ReadFile(testInputFileTemp)
+	if err != nil {
+		t.Fatal(err)
+	}
+	expectedExpr := "Address[ \t]+string[ \t]+`protobuf:\"bytes,1,opt,name=Address,proto3\" json:\"overrided\" valid:\"ip\" yaml:\"ip\"`"
+	matched, err := regexp.Match(expectedExpr, contents)
+	if err != nil || matched != true {
+		t.Error("file doesn't contains custom tag after writing")
+		t.Log(string(contents))
+	}
+}
+
+func TestParseWriteFileClearCommon(t *testing.T) {
+	expectedTag := `valid:"ip" yaml:"ip" json:"overrided"`
+
+	areas, err := parseFile(testInputFile, []string{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(areas) != 9 {
+		t.Fatalf("expected 9 areas to replace, got: %d", len(areas))
+	}
+	area := areas[0]
+	if area.InjectTag != expectedTag {
+		t.Errorf("expected tag: %q, got: %q", expectedTag, area.InjectTag)
+	}
+
+	// make a copy of test file
+	contents, err := ioutil.ReadFile(testInputFile)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err = ioutil.WriteFile(testInputFileTemp, contents, 0644); err != nil {
+		t.Fatal(err)
+	}
+	defer os.Remove(testInputFileTemp)
+
+	if err = writeFile(testInputFileTemp, areas, true); err != nil {
+		t.Fatal(err)
+	}
+	newAreas, err := parseFile(testInputFileTemp, []string{})
+	if newAreas != nil {
+		t.Errorf("not clear tag")
+	}
+	if err != nil {
 		t.Fatal(err)
 	}
 
@@ -148,7 +205,7 @@ func TestContinueParsingWhenSkippingFields(t *testing.T) {
 	}
 	defer os.Remove(testInputFileTemp)
 
-	if err = writeFile(testInputFileTemp, areas); err != nil {
+	if err = writeFile(testInputFileTemp, areas, false); err != nil {
 		t.Fatal(err)
 	}
 

parse.go

@@ -62,15 +62,35 @@ func newTagItems(tag string) tagItems {
 	return items
 }
 
-func injectTag(contents []byte, area textArea) (injected []byte) {
+func injectTag(contents []byte, area textArea, clearTagCommon bool) (injected []byte) {
 	expr := make([]byte, area.End-area.Start)
 	copy(expr, contents[area.Start-1:area.End-1])
 	cti := newTagItems(area.CurrentTag)
 	iti := newTagItems(area.InjectTag)
 	ti := cti.override(iti)
 	expr = rInject.ReplaceAll(expr, []byte(fmt.Sprintf("`%s`", ti.format())))
-	injected = append(injected, contents[:area.Start-1]...)
-	injected = append(injected, expr...)
-	injected = append(injected, contents[area.End-1:]...)
+	if clearTagCommon {
+		black := make([]byte, area.CommentEnd-area.CommentStart)
+		copy(black, contents[area.CommentStart-1:area.CommentEnd-1])
+		black = rAll.ReplaceAll(expr, []byte(" "))
+		if area.CommentStart < area.Start {
+			injected = append(injected, contents[:area.CommentStart-1]...)
+			injected = append(injected, black...)
+			injected = append(injected, contents[area.CommentEnd-1:area.Start-1]...)
+			injected = append(injected, expr...)
+			injected = append(injected, contents[area.End-1:]...)
+		} else {
+			injected = append(injected, contents[:area.Start-1]...)
+			injected = append(injected, expr...)
+			injected = append(injected, contents[area.End-1:area.CommentStart-1]...)
+			injected = append(injected, black...)
+			injected = append(injected, contents[area.CommentEnd-1:]...)
+		}
+	} else {
+		injected = append(injected, contents[:area.Start-1]...)
+		injected = append(injected, expr...)
+		injected = append(injected, contents[area.End-1:]...)
+	}
+
 	return
 }