From 84b67a8f53f6ccfe8c1856c3c994378b08c8454d Mon Sep 17 00:00:00 2001
From: "Lea\\Anthony" <lea.anthony@gmail.com>
Date: Tue, 28 Dec 2021 06:40:35 +1100
Subject: [PATCH] Add -u flag to sync project go.mod with CLI version

---
 v2/cmd/wails/internal/commands/build/build.go | 40 +++++++++++++++++--
 website/docs/reference/cli.mdx                |  1 +
 2 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/v2/cmd/wails/internal/commands/build/build.go b/v2/cmd/wails/internal/commands/build/build.go
index 86df08ec4..c0415facf 100644
--- a/v2/cmd/wails/internal/commands/build/build.go
+++ b/v2/cmd/wails/internal/commands/build/build.go
@@ -2,6 +2,7 @@ package build
 
 import (
 	"fmt"
+	"github.com/wailsapp/wails/v2/internal/colour"
 	"io"
 	"os"
 	"os/exec"
@@ -79,6 +80,9 @@ func AddBuildSubcommand(app *clir.Cli, w io.Writer) {
 	forceBuild := false
 	command.BoolFlag("f", "Force build application", &forceBuild)
 
+	updateGoMod := false
+	command.BoolFlag("u", "Updates go.mod to use the same Wails version as the CLI", &updateGoMod)
+
 	command.Action(func() error {
 
 		quiet := verbosity == 0
@@ -214,7 +218,7 @@ func AddBuildSubcommand(app *clir.Cli, w io.Writer) {
 		fmt.Fprintf(w, "\n")
 		w.Flush()
 
-		err = checkGoModVersion(logger)
+		err = checkGoModVersion(logger, updateGoMod)
 		if err != nil {
 			return err
 		}
@@ -243,7 +247,7 @@ func doBuild(buildOptions *build.Options) error {
 	return nil
 }
 
-func checkGoModVersion(logger *clilogger.CLILogger) error {
+func checkGoModVersion(logger *clilogger.CLILogger, updateGoMod bool) error {
 	cwd, err := os.Getwd()
 	if err != nil {
 		return err
@@ -265,6 +269,36 @@ func checkGoModVersion(logger *clilogger.CLILogger) error {
 		return err
 	}
 
-	logger.Println("Warning: go.mod is using Wails '%s' but the CLI is '%s'. Consider updating it.\n", gomodversion.String(), internal.Version)
+	if updateGoMod {
+		return syncGoModVersion(cwd)
+	}
+
+	logger.Println("Warning: go.mod is using Wails '%s' but the CLI is '%s'. Consider updating your project's `go.mod` file.\n", gomodversion.String(), internal.Version)
 	return nil
 }
+
+func LogGreen(message string, args ...interface{}) {
+	text := fmt.Sprintf(message, args...)
+	println(colour.Green(text))
+}
+
+func syncGoModVersion(cwd string) error {
+	gomodFilename := filepath.Join(cwd, "go.mod")
+	gomodData, err := os.ReadFile(gomodFilename)
+	if err != nil {
+		return err
+	}
+	outOfSync, err := gomod.GoModOutOfSync(gomodData, internal.Version)
+	if err != nil {
+		return err
+	}
+	if !outOfSync {
+		return nil
+	}
+	LogGreen("Updating go.mod to use Wails '%s'", internal.Version)
+	newGoData, err := gomod.UpdateGoModVersion(gomodData, internal.Version)
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(gomodFilename, newGoData, 0755)
+}
diff --git a/website/docs/reference/cli.mdx b/website/docs/reference/cli.mdx
index 3ae0c4565..4f6f07ae9 100644
--- a/website/docs/reference/cli.mdx
+++ b/website/docs/reference/cli.mdx
@@ -66,6 +66,7 @@ A list of community maintained templates can be found [here](/docs/community/tem
 |  -upxflags           | Flags to pass to upx                    |                            |
 |  -v int              | Verbosity level (0 - silent, 1 - default, 2 - verbose) | 1           |
 |  -webview2           | WebView2 installer strategy: download,embed,browser,error | download |
+|  -u                  | Updates your project's `go.mod` to use the same version of Wails as the CLI | |
 
 For a detailed description of the `webview2` flag, please refer to the [Windows](/docs/guides/windows) Guide.