feat(abigen): Add flag let be able to add user tmpl file. (#362)

* Add user tmpl file.

* Update accounts/abi/bind/template.go

Co-authored-by: HAOYUatHZ <37070449+HAOYUatHZ@users.noreply.github.com>

* Update cmd/abigen/main.go

Co-authored-by: HAOYUatHZ <37070449+HAOYUatHZ@users.noreply.github.com>

* Update cmd/abigen/main.go

Co-authored-by: HAOYUatHZ <37070449+HAOYUatHZ@users.noreply.github.com>

* Update cmd/abigen/main.go

Co-authored-by: HAOYUatHZ <37070449+HAOYUatHZ@users.noreply.github.com>

* fix bug

---------

Co-authored-by: HAOYUatHZ <37070449+HAOYUatHZ@users.noreply.github.com>

accounts/abi/bind/template.go

@@ -79,6 +79,13 @@ var tmplSource = map[Lang]string{
 	LangJava: tmplSourceJava,
 }
 
+// SetTmplSource supports this func in order to set special template file.
+func SetTmplSource(lang Lang, source string) {
+	if _, ok := tmplSource[lang]; ok {
+		tmplSource[lang] = source
+	}
+}
+
 // tmplSourceGo is the Go source template that the generated Go contract binding
 // is based on.
 const tmplSourceGo = `

cmd/abigen/main.go

@@ -103,6 +103,10 @@ var (
 		Name:  "contract",
 		Usage: "Name of the contract to generate the bindings for",
 	}
+	tmplFlag = cli.StringFlag{
+		Name:  "tmpl",
+		Usage: "Template file if a user wants to customize",
+	}
 )
 
 func init() {
@@ -122,6 +126,7 @@ func init() {
 		langFlag,
 		aliasFlag,
 		contractFlag,
+		tmplFlag,
 	}
 	app.Action = utils.MigrateFlags(abigen)
 	cli.CommandHelpTemplate = flags.OriginCommandHelpTemplate
@@ -265,6 +270,15 @@ func abigen(c *cli.Context) error {
 			aliases[match[1]] = match[2]
 		}
 	}
+	// Set customize template file.
+	if c.GlobalIsSet(tmplFlag.Name) {
+		tmplFile := c.GlobalString(tmplFlag.Name)
+		data, err := os.ReadFile(tmplFile)
+		if err != nil {
+			utils.Fatalf("Failed to read template file: %v", err)
+		}
+		bind.SetTmplSource(lang, string(data))
+	}
 	// Generate the contract binding
 	code, err := bind.Bind(types, abis, bins, sigs, c.GlobalString(pkgFlag.Name), lang, libs, aliases)
 	if err != nil {