Support wails3 generate runtime

mkdocs-website/docs/en/changelog.md

@@ -21,6 +21,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Templates for sveltekit and sveltekit-ts that are set for non-SSR development by [atterpac](https://github.com/atterpac) in [#3829](https://github.com/wailsapp/wails/pull/3829)
 - Update build assets using new `wails3 update build-assets` command by [leaanthony](https://github.com/leaanthony).
 - Example to test the HTML Drag and Drop API by [FerroO2000](https://github.com/FerroO2000) in [#3856](https://github.com/wailsapp/wails/pull/3856)
+- New `wails3 generate runtime` command by [leaanthony](https://github.com/leaanthony)
 
 ### Changed
 - Taskfile refactor by [leaanthony](https://github.com/leaanthony) in [#3748](https://github.com/wailsapp/wails/pull/3748)

v3/cmd/wails3/main.go

@@ -48,6 +48,7 @@ func main() {
 	generate.NewSubCommandFunction("build-assets", "Generate build assets", commands.GenerateBuildAssets)
 	generate.NewSubCommandFunction("icons", "Generate icons", commands.GenerateIcons)
 	generate.NewSubCommandFunction("syso", "Generate Windows .syso file", commands.GenerateSyso)
+	generate.NewSubCommandFunction("runtime", "Generate the pre-built version of the runtime", commands.GenerateRuntime)
 
 	update := app.NewSubCommand("update", "Update tools")
 	update.NewSubCommandFunction("build-assets", "Updates the build assets using the given config file", commands.UpdateBuildAssets)

v3/internal/commands/runtime.go

@@ -0,0 +1,47 @@
+package commands
+
+import (
+	"io"
+	"os"
+	"path/filepath"
+	"runtime"
+)
+
+type RuntimeOptions struct {
+	Directory string `name:"d" description:"Directory to generate runtime file in" default:"."`
+}
+
+func GenerateRuntime(options *RuntimeOptions) error {
+	DisableFooter = true
+	_, thisFile, _, _ := runtime.Caller(0)
+	localDir := filepath.Dir(thisFile)
+	bundledAssetsDir := filepath.Join(localDir, "..", "assetserver", "bundledassets")
+	runtimeJS := filepath.Join(bundledAssetsDir, "runtime.js")
+	err := CopyFile(runtimeJS, filepath.Join(options.Directory, "runtime.js"))
+	if err != nil {
+		return err
+	}
+	runtimeDebugJS := filepath.Join(bundledAssetsDir, "runtime.debug.js")
+	err = CopyFile(runtimeDebugJS, filepath.Join(options.Directory, "runtime-debug.js"))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func CopyFile(source string, target string) error {
+	s, err := os.Open(source)
+	if err != nil {
+		return err
+	}
+	defer s.Close()
+	d, err := os.Create(target)
+	if err != nil {
+		return err
+	}
+	if _, err := io.Copy(d, s); err != nil {
+		d.Close()
+		return err
+	}
+	return d.Close()
+}