Allow merge the exists description/workaround in errors.toml (#867)

Signed-off-by: Lonng <[email protected]>

components/errdoc/errdoc-gen/main.go

@@ -29,15 +29,17 @@ import (
 )
 
 var opt struct {
-	source string
-	module string
-	output string
+	source     string
+	module     string
+	output     string
+	retainCode bool
 }
 
 func init() {
 	flag.StringVar(&opt.source, "source", "", "The source directory of error documentation")
 	flag.StringVar(&opt.module, "module", "", "The module name of target repository")
 	flag.StringVar(&opt.output, "output", "", "The output path of error documentation file")
+	flag.BoolVar(&opt.retainCode, "retain-code", false, "Retain the generated code when generator exit")
 }
 
 func log(format string, args ...interface{}) {
@@ -82,7 +84,10 @@ func main() {
 	if err := os.MkdirAll(targetDir, 0755); err != nil {
 		fatal("Cannot create the errdoc: %+v", err)
 	}
-	defer os.RemoveAll(targetDir)
+
+	if !opt.retainCode {
+		defer os.RemoveAll(targetDir)
+	}
 
 	tmpl := `
 package main
@@ -95,7 +100,9 @@ import (
 	"reflect"
 	"fmt"
 	"sort"
+	"strings"
 
+	"github.com/BurntSushi/toml"
 	"github.com/pingcap/errors"
 {{- range $decl := .}}
 	{{$decl.PackageName}} "{{- $decl.ImportPath}}"
@@ -107,23 +114,27 @@ func main() {
 	flag.StringVar(&outpath, "output", "", "Specify the error documentation output file path")
 	flag.Parse()
 	if outpath == "" {
-		println("Usage: ./_errdoc-generator --out /path/to/errors.toml")
+		println("Usage: ./_errdoc-generator --output /path/to/errors.toml")
 		os.Exit(1)
 	}
+
+	// Read-in the exists file and merge the description/workaround from exists file
+	existDefinition := map[string]spec{}
+	if file, err := ioutil.ReadFile(outpath); err == nil {
+		err = toml.Unmarshal(file, &existDefinition)
+		if err != nil {
+			println(fmt.Sprintf("Invalid toml file %s when merging exists description/workaround: %v", outpath, err))
+			os.Exit(1)
+		}
+	}
 	
 	var allErrors []error
 	{{- range $decl := .}}
 		{{- range $err := $decl.ErrNames}}
-			allErrors = append(allErrors, {{$decl.PackageName}}.{{- $err}})
+	allErrors = append(allErrors, {{$decl.PackageName}}.{{- $err}})
 		{{- end}}
 	{{- end}}
-	
-	type spec struct {
-		Code        string
-		Message     string
-		Description string
-		Workaround  string
-	}
+
 	var dedup = map[string]spec{}
 	for _, e := range allErrors {
 		terr, ok := e.(*errors.Error)
@@ -135,21 +146,17 @@ func main() {
 			message := val.FieldByName("message")
 			if previous, found := dedup[codeText.String()]; found {
 				println("Duplicated error code:", codeText.String())
-				if message.String() < previous.Message {
+				if message.String() < previous.Error {
 					continue
 				}
 			}
-			description := val.FieldByName("description")
-			workaround := val.FieldByName("workaround ")
 			s := spec{
-				Code:    codeText.String(),
-				Message: message.String(),
-			}
-			if description.IsValid() {
-				s.Description = description.String()
+				Code:  codeText.String(),
+				Error: message.String(),
 			}
-			if workaround.IsValid() {
-				s.Workaround = workaround.String()
+			if exist, found := existDefinition[s.Code]; found {
+				s.Description = strings.TrimSpace(exist.Description)
+				s.Workaround = strings.TrimSpace(exist.Workaround)
 			}
 			dedup[codeText.String()] = s
 		}
@@ -162,16 +169,16 @@ func main() {
 	sort.Slice(sorted, func(i, j int) bool {
 		// TiDB exits duplicated code
 		if sorted[i].Code == sorted[j].Code {
-			return sorted[i].Message < sorted[j].Message
+			return sorted[i].Error < sorted[j].Error
 		}
 		return sorted[i].Code < sorted[j].Code
 	})
 
 	// We don't use toml library to serialize it due to cannot reserve the order for map[string]spec
 	buffer := bytes.NewBufferString("# AUTOGENERATED BY github.com/pingcap/tiup/components/errdoc/errdoc-gen\n" +
-		"# DO NOT EDIT THIS FILE, PLEASE CHANGE ERROR DEFINITION IF CONTENT IMPROPER.\n\n")
+		"# YOU CAN CHANGE THE 'description'/'workaround' FIELDS IF THEM ARE IMPROPER.\n\n")
 	for _, item := range sorted {
-		buffer.WriteString(fmt.Sprintf("[\"%s\"]\nerror = '''\n%s\n'''\n", item.Code, item.Message))
+		buffer.WriteString(fmt.Sprintf("[\"%s\"]\nerror = '''\n%s\n'''\n", item.Code, item.Error))
 		if item.Description != "" {
 			buffer.WriteString(fmt.Sprintf("description = '''\n%s\n'''\n", item.Description))
 		}
@@ -184,7 +191,12 @@ func main() {
 		panic(err)
 	}
 }
-`
+` + "type spec struct {\n" +
+		"Code        string\n" +
+		"Error       string `toml:\"error\"`\n" +
+		"Description string `toml:\"description\"`\n" +
+		"Workaround  string `toml:\"workaround\"`\n" +
+		"}"
 
 	t, err := template.New("_errdoc-template").Parse(tmpl)
 	if err != nil {