feat(cli): ags run naive --watch mode

cmd/run.go

@@ -5,16 +5,19 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"os/exec"
 	"path/filepath"
 
 	"github.com/spf13/cobra"
 )
 
+
 var (
 	gtk4      bool
 	targetDir string
 	logFile   string
 	args      []string
+	watch     bool
 )
 
 var runCommand = &cobra.Command{
@@ -58,6 +61,7 @@ when no positional argument is given
 	f.StringArrayVarP(&args, "arg", "a", []string{}, "cli args to pass to gjs")
 	f.StringVar(&logFile, "log-file", "", "file to redirect the stdout of gjs to")
 	f.BoolVarP(&usePackage, "package", "p", false, "use astal package as defined in package.json")
+	f.BoolVarP(&watch, "watch", "w", false, "watch for changes and restart the app")
 	f.MarkHidden("package")
 }
 
@@ -107,41 +111,76 @@ func logging() (io.Writer, io.Writer, *os.File) {
 	return io.MultiWriter(os.Stdout, file), io.MultiWriter(os.Stderr, file), file
 }
 
+var gjs *exec.Cmd
+func executeGjs(infile string, stdout io.Writer, stderr io.Writer) *exec.Cmd {
+	if(gjs != nil) {
+		if err := gjs.Process.Kill(); err != nil {
+			lib.Err(err)
+		}
+		gjs.Wait()
+	}
+
+	if gtk4 {
+		os.Setenv("LD_PRELOAD", gtk4LayerShell)
+	}
+
+	outfile := getOutfile()
+	args := append([]string{"-m", outfile}, args...)
+	gjs = lib.Exec("gjs", args...)
+
+	gjs.Stdin = os.Stdin
+	gjs.Dir = filepath.Dir(infile)
+
+	gjs.Stdout = stdout
+	gjs.Stderr = stderr
+
+	return gjs
+}
+
 func run(infile string, rootdir string) {
 	gtk := 3
 	if gtk4 {
 		gtk = 4
 	}
 
-	outfile := getOutfile()
-	lib.Bundle(lib.BundleOpts{
+	bundleOpts := lib.BundleOpts{
 		Infile:           infile,
-		Outfile:          outfile,
+		Outfile:          getOutfile(),
 		Defines:          defines,
 		UsePackage:       usePackage,
 		GtkVersion:       gtk,
 		WorkingDirectory: rootdir,
-	})
-
-	if gtk4 {
-		os.Setenv("LD_PRELOAD", gtk4LayerShell)
 	}
 
-	args = append([]string{"-m", outfile}, args...)
 	stdout, stderr, file := logging()
-	gjs := lib.Exec("gjs", args...)
-	gjs.Stdin = os.Stdin
-	gjs.Dir = filepath.Dir(infile)
 
-	gjs.Stdout = stdout
-	gjs.Stderr = stderr
-
-	// TODO: watch and restart
-	if err := gjs.Run(); err != nil {
-		lib.Err(err)
+	if(watch){
+		lib.Watch(lib.WatchOpts{
+			BundleOpts: bundleOpts,
+			ReloadPluginOpts: lib.ReloadPluginOpts{
+				OnBuild: func(){
+					gjs = executeGjs(infile, stdout, stderr)
+					gjs.Start()
+				},
+				OnExit: func(){
+					if file != nil {
+						file.Close()
+					}
+				},
+			},
+		})
+	} else {
+		lib.Bundle(bundleOpts)
+
+		gjs = executeGjs(infile, stdout, stderr)
+
+		if err := gjs.Run(); err != nil {
+			lib.Err(err)
+		}
+
+		if file != nil {
+			file.Close()
+		}
 	}
 
-	if file != nil {
-		file.Close()
-	}
-}
+}

lib/esbuild.go

@@ -117,6 +117,28 @@ var blpPlugin api.Plugin = api.Plugin{
 	},
 }
 
+
+type ReloadPluginOpts struct {
+	OnBuild func()
+	OnExit func()
+}
+
+func makeReloadPlugin(opts ReloadPluginOpts) api.Plugin {
+	return api.Plugin {
+		Name: "reload",
+		Setup: func(build api.PluginBuild) {
+			build.OnEnd(func(result *api.BuildResult) (api.OnEndResult, error) {
+				opts.OnBuild()
+				return api.OnEndResult{}, nil
+			})
+
+			build.OnDispose(func() {
+				opts.OnExit()
+			})
+		},
+	}
+}
+
 func sliceToKV(keyValuePairs []string) map[string]string {
 	pairs := make(map[string]string)
 	for _, pair := range keyValuePairs {
@@ -143,7 +165,7 @@ type BundleOpts struct {
 // svg loader
 // other css preproceccors
 // http plugin with caching
-func Bundle(opts BundleOpts) {
+func Prepare(opts BundleOpts) api.BuildOptions {
 	defines := sliceToKV(opts.Defines)
 
 	if _, ok := defines["SRC"]; !ok {
@@ -203,10 +225,41 @@ func Bundle(opts BundleOpts) {
 		}
 	}
 
-	result := api.Build(buildOpts)
+	return buildOpts
+}
+
 
-	// TODO: custom error logs
-	if len(result.Errors) > 0 {
-		os.Exit(1)
+func Bundle(opts BundleOpts) api.BuildResult {
+	ctx := Prepare(opts)
+	result := api.Build(ctx)
+
+	if result.Errors != nil {
+		Err(result.Errors)
 	}
+
+	return result
+}
+
+type WatchOpts struct {
+	BundleOpts
+	ReloadPluginOpts
 }
+
+func Watch(opts WatchOpts){
+	buildOpts := Prepare(opts.BundleOpts)
+
+	buildOpts.Plugins = append(buildOpts.Plugins, makeReloadPlugin(opts.ReloadPluginOpts))
+
+	ctx, ctxErr := api.Context(buildOpts)
+	if ctxErr != nil {
+		Err(ctxErr)
+	}
+
+	watchErr := ctx.Watch(api.WatchOptions{})
+
+	if watchErr != nil {
+		Err(watchErr)
+	}
+
+	<-make(chan struct{})
+}