EsBuild with on-request rebuild and hot-reloading

go.mod

@@ -44,6 +44,7 @@ require (
 	github.com/danwakefield/fnmatch v0.0.0-20160403171240-cbb64ac3d964 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/dlclark/regexp2 v1.4.0 // indirect
+	github.com/evanw/esbuild v0.21.4 // indirect
 	github.com/huandu/xstrings v1.3.2 // indirect
 	github.com/imdario/mergo v0.3.12 // indirect
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect

go.sum

@@ -90,6 +90,8 @@ github.com/dlclark/regexp2 v1.4.0 h1:F1rxgk7p4uKjwIQxBs9oAXe5CqrXlCduYEJvrF4u93E
 github.com/dlclark/regexp2 v1.4.0/go.mod h1:2pZnwuY/m+8K6iRw6wQdMtk+rH5tNGR1i55kozfMjCc=
 github.com/emersion/go-ical v0.0.0-20220601085725-0864dccc089f h1:feGUUxxvOtWVOhTko8Cbmp33a+tU0IMZxMEmnkoAISQ=
 github.com/emersion/go-ical v0.0.0-20220601085725-0864dccc089f/go.mod h1:2MKFUgfNMULRxqZkadG1Vh44we3y5gJAtTBlVsx1BKQ=
+github.com/evanw/esbuild v0.21.4 h1:pe4SEQMoR1maEjhgWPEPWmUy11Jp6nidxd1mOvMrFFU=
+github.com/evanw/esbuild v0.21.4/go.mod h1:D2vIQZqV/vIf/VRHtViaUtViZmG7o+kKmlBfVQuRi48=
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
 github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/ghodss/yaml v1.0.0/go.mod h1:4dBDuWmgqj2HViK6kFavaiC9ZROes6MMH2rRYeMEF04=
@@ -369,6 +371,7 @@ golang.org/x/sys v0.0.0-20200223170610-d5e6a3e2c0ae/go.mod h1:h1NjWce9XRLGQEsW7w
 golang.org/x/sys v0.0.0-20200413165638-669c56c373c4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20210927094055-39ccf1dd6fa6/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.0.0-20220715151400-c0bba94af5f8/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.5.0 h1:MUK/U/4lj1t1oPg0HfuXDN/Z1wv31ZJ/YcPiGccS4DU=
 golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=

main.go

@@ -3,7 +3,7 @@ package main
 import (
 	_ "git.handmade.network/hmn/hmn/src/admintools"
 	_ "git.handmade.network/hmn/hmn/src/assets"
-	_ "git.handmade.network/hmn/hmn/src/buildscss"
+	_ "git.handmade.network/hmn/hmn/src/buildscss/cmd"
 	_ "git.handmade.network/hmn/hmn/src/discord/cmd"
 	_ "git.handmade.network/hmn/hmn/src/initimage"
 	_ "git.handmade.network/hmn/hmn/src/migration"

public/style.css

@@ -8480,7 +8480,7 @@ header.clicked .root-item:not(.clicked) > .submenu {
 /* src/rawdata/scss/icons.css */
 @font-face {
   font-family: icons;
-  src: url("./icons-7ANC2ICW.ttf?v=4");
+  src: url(/public/icons.ttf?v=4);
 }
 span.icon {
   font-family: "icons";

src/buildscss/buildscss.go

@@ -1,85 +1,64 @@
 package buildscss
 
-/*
+import (
+	"context"
 
-var compressed bool
+	"git.handmade.network/hmn/hmn/src/config"
+	"git.handmade.network/hmn/hmn/src/jobs"
+	"git.handmade.network/hmn/hmn/src/logging"
+	"github.com/evanw/esbuild/pkg/api"
+)
 
-func init() {
+var ActiveServerPort uint16
-	libsass.RegisterSassFunc("base64($filename)", func(ctx context.Context, in libsass.SassValue) (*libsass.SassValue, error) {
-		var filename string
-		err := libsass.Unmarshal(in, &filename)
-		if err != nil {
-			return nil, err
-		}
 
-		fileBytes, err := os.ReadFile(filename)
+func RunServer(ctx context.Context) jobs.Job {
-		if err != nil {
+	job := jobs.New()
-			return nil, err
+	if config.Config.Env != config.Dev {
-		}
+		job.Done()
-
+		return job
-		encoded, _ := libsass.Marshal(base64.StdEncoding.EncodeToString(fileBytes))
+	}
-		return &encoded, nil
+	logger := logging.ExtractLogger(ctx).With().Str("module", "EsBuild").Logger()
-	})
+	esCtx, ctxErr := BuildContext()
-
+	if ctxErr != nil {
-	buildCommand := &cobra.Command{
+		panic(ctxErr)
-		Use:   "buildscss",
+	}
-		Short: "Build the website CSS",
+	logger.Info().Msg("Starting esbuild server and watcher")
-		Run: func(cmd *cobra.Command, args []string) {
+	err := esCtx.Watch(api.WatchOptions{})
-			style := libsass.NESTED_STYLE
+	serverResult, err := esCtx.Serve(api.ServeOptions{
-			if compressed {
+		Port:     config.Config.EsBuild.Port,
-				style = libsass.COMPRESSED_STYLE
+		Servedir: "./",
-			}
+		OnRequest: func(args api.ServeOnRequestArgs) {
-
+			logger.Info().Interface("args", args).Msg("Response from esbuild server")
-			err := compile("src/rawdata/scss/style.scss", "public/style.css", "light", style)
-			if err != nil {
-				fmt.Println(color.Bold + color.Red + "Failed to compile main SCSS." + color.Reset)
-				fmt.Println(err)
-				os.Exit(1)
-			}
-
-			for _, theme := range []string{"light", "dark"} {
-				err := compile("src/rawdata/scss/theme.scss", fmt.Sprintf("public/themes/%s/theme.css", theme), theme, style)
-				if err != nil {
-					fmt.Println(color.Bold + color.Red + "Failed to compile theme SCSS." + color.Reset)
-					fmt.Println(err)
-					os.Exit(1)
-				}
-			}
 		},
+	})
+	if err != nil {
+		panic(err)
 	}
-	buildCommand.Flags().BoolVar(&compressed, "compressed", false, "Minify the output CSS")
+	ActiveServerPort = serverResult.Port
+	go func() {
+		<-ctx.Done()
+		logger.Info().Msg("Shutting down esbuild server and watcher")
+		esCtx.Dispose()
+		job.Done()
+	}()
 
-	website.WebsiteCommand.AddCommand(buildCommand)
+	return job
 }
 
-func compile(inpath, outpath string, theme string, style int) error {
+func BuildContext() (api.BuildContext, *api.ContextError) {
-	err := os.MkdirAll(filepath.Dir(outpath), 0755)
+	return api.Context(api.BuildOptions{
-	if err != nil {
+		EntryPoints: []string{
-		panic(oops.New(err, "failed to create directory for CSS file"))
+			"src/rawdata/scss/style.css",
-	}
+		},
-
+		Outbase:  "src/rawdata/scss",
-	outfile, err := os.OpenFile(outpath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
+		Outdir:   "public",
-	if err != nil {
+		External: []string{"/public/*"},
-		panic(oops.New(err, "failed to open CSS file for writing"))
+		Bundle:   true,
-	}
+		Write:    true,
-	defer outfile.Close()
+		Engines: []api.Engine{
-
+			{Name: api.EngineChrome, Version: "109"},
-	infile, err := os.Open(inpath)
+			{Name: api.EngineFirefox, Version: "109"},
-	if err != nil {
+			{Name: api.EngineSafari, Version: "12"},
-		panic(oops.New(err, "failed to open SCSS file"))
+		},
-	}
+	})
-	compiler, err := libsass.New(outfile, infile,
-		libsass.IncludePaths([]string{
-			"src/rawdata/scss",
-			fmt.Sprintf("src/rawdata/scss/themes/%s", theme),
-		}),
-		libsass.OutputStyle(style),
-	)
-	if err != nil {
-		panic(oops.New(err, "failed to create SCSS compiler"))
-	}
-
-	return compiler.Run()
 }
-
-*/

src/buildscss/cmd/cmd.go

@@ -0,0 +1,39 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+
+	"git.handmade.network/hmn/hmn/src/buildscss"
+	"git.handmade.network/hmn/hmn/src/logging"
+	"git.handmade.network/hmn/hmn/src/website"
+	"github.com/spf13/cobra"
+)
+
+func init() {
+	buildCommand := &cobra.Command{
+		Use:   "buildscss",
+		Short: "Build the website CSS",
+		Run: func(cmd *cobra.Command, args []string) {
+			ctx, err := buildscss.BuildContext()
+			if err != nil {
+				fmt.Println(err)
+				os.Exit(1)
+			}
+
+			res := ctx.Rebuild()
+			outputFilenames := make([]string, 0)
+			for _, o := range res.OutputFiles {
+				outputFilenames = append(outputFilenames, o.Path)
+			}
+			logging.Info().
+				Interface("Errors", res.Errors).
+				Interface("Warnings", res.Warnings).
+				Msg("Ran esbuild")
+			if len(outputFilenames) > 0 {
+				logging.Info().Interface("Files", outputFilenames).Msg("Wrote files")
+			}
+		},
+	}
+	website.WebsiteCommand.AddCommand(buildCommand)
+}

src/config/config.go.example

@@ -91,4 +91,7 @@ var Config = HMNConfig{
         FFMpegPath: "", // Will not generate asset video thumbnails if ffmpeg is not specified
         CPULimitPath: "", // Not mandatory. FFMpeg will not limited if this is not provided
     },
+	EsBuild: EsBuildConfig{
+		Port: 9004,
+	},
 }

src/config/types.go

@@ -32,7 +32,8 @@ type HMNConfig struct {
 	EpisodeGuide      EpisodeGuide
 	DevConfig         DevConfig
 	PreviewGeneration PreviewGenerationConfig
-	Calendars      []CalendarSource
+	Calendars         []CalendarSource
+	EsBuild           EsBuildConfig
 }
 
 type PostgresConfig struct {
@@ -104,7 +105,7 @@ type MatrixConfig struct {
 
 type CalendarSource struct {
 	Name string
-	Url string
+	Url  string
 }
 
 type EpisodeGuide struct {
@@ -126,6 +127,10 @@ type PreviewGenerationConfig struct {
 	CPULimitPath string
 }
 
+type EsBuildConfig struct {
+	Port uint16
+}
+
 func init() {
 	if Config.EpisodeGuide.Projects == nil {
 		Config.EpisodeGuide.Projects = make(map[string]string)

src/hmnurl/urls.go

@@ -981,6 +981,13 @@ func BuildS3Asset(s3key string) string {
 	return res
 }
 
+var RegexEsBuild = regexp.MustCompile("^/esbuild$")
+
+func BuildEsBuild() string {
+	defer CatchPanic()
+	return Url("/esbuild", nil)
+}
+
 var RegexPublic = regexp.MustCompile("^/public/.+$")
 
 func BuildPublic(filepath string, cachebust bool) string {

src/rawdata/scss/icons.css

@@ -1,6 +1,6 @@
 @font-face {
   font-family: icons;
-  src: url("icons.ttf?v=4");
+  src: url("/public/icons.ttf?v=4");
 }
 
 span.icon {

src/templates/src/layouts/base.html

@@ -68,6 +68,29 @@
     </script>
     <script async src="{{ static "mathjax.js" }}"></script>
 
+	{{ if .EsBuildSSEUrl }}
+	<script>
+		new EventSource("{{ .EsBuildSSEUrl }}").addEventListener('change', e => {
+			const { added, removed, updated } = JSON.parse(e.data)
+
+			console.log("EsBuild", added, removed, updated);
+			if (!added.length && !removed.length && updated.length === 1) {
+				for (const link of document.getElementsByTagName("link")) {
+					const url = new URL(link.href)
+
+					if (url.host === location.host && url.pathname === updated[0]) {
+						const next = link.cloneNode()
+						next.href = updated[0] + '?' + Math.random().toString(36).slice(2)
+						next.onload = () => link.remove()
+						link.parentNode.insertBefore(next, link.nextSibling)
+						return
+					}
+				}
+			}
+		})
+	</script>
+	{{ end }}
+
     {{ block "extrahead" . }}{{ end }}
 </head>
 

src/templates/types.go

@@ -23,6 +23,8 @@ type BaseData struct {
 	DiscordInviteUrl    string
 	NewsletterSignupUrl string
 
+	EsBuildSSEUrl string
+
 	Project Project
 	User    *User
 	Session *Session

src/website/base_data.go

@@ -1,6 +1,7 @@
 package website
 
 import (
+	"git.handmade.network/hmn/hmn/src/buildscss"
 	"git.handmade.network/hmn/hmn/src/config"
 	"git.handmade.network/hmn/hmn/src/hmnurl"
 	"git.handmade.network/hmn/hmn/src/models"
@@ -96,6 +97,10 @@ func getBaseData(c *RequestContext, title string, breadcrumbs []templates.Breadc
 		},
 	}
 
+	if buildscss.ActiveServerPort != 0 {
+		baseData.EsBuildSSEUrl = hmnurl.BuildEsBuild()
+	}
+
 	if c.CurrentUser != nil {
 		baseData.Header.UserProfileUrl = hmnurl.BuildUserProfile(c.CurrentUser.Username)
 	}

src/website/requesthandling.go

@@ -408,6 +408,8 @@ type ResponseData struct {
 	FutureNotices []templates.Notice
 
 	header http.Header
+
+	hijacked bool
 }
 
 var _ http.ResponseWriter = &ResponseData{}
@@ -480,6 +482,12 @@ func doRequest(rw http.ResponseWriter, c *RequestContext, h Handler) {
 	// Run the chosen handler
 	res := h(c)
 
+	if res.hijacked {
+		// NOTE(asaf): In case we forward the request/response to another handler
+		//             (like esbuild).
+		return
+	}
+
 	if res.StatusCode == 0 {
 		res.StatusCode = http.StatusOK
 	}

src/website/routes.go

@@ -1,16 +1,22 @@
 package website
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
+	"io"
 	"net/http"
+	"net/http/httputil"
 	"strconv"
+	"strings"
 	"time"
 
+	"git.handmade.network/hmn/hmn/src/buildscss"
 	"git.handmade.network/hmn/hmn/src/db"
 	"git.handmade.network/hmn/hmn/src/email"
 	"git.handmade.network/hmn/hmn/src/hmndata"
 	"git.handmade.network/hmn/hmn/src/hmnurl"
+	"git.handmade.network/hmn/hmn/src/logging"
 	"git.handmade.network/hmn/hmn/src/models"
 	"git.handmade.network/hmn/hmn/src/oops"
 	"git.handmade.network/hmn/hmn/src/utils"
@@ -37,8 +43,53 @@ func NewWebsiteRoutes(conn *pgxpool.Pool) http.Handler {
 		redirectToHMN,
 	)
 
+	routes.GET(hmnurl.RegexEsBuild, func(c *RequestContext) ResponseData {
+		if buildscss.ActiveServerPort != 0 {
+			var res ResponseData
+			proxy := httputil.ReverseProxy{
+				Director: func(r *http.Request) {
+					r.URL.Scheme = "http"
+					r.URL.Host = fmt.Sprintf("localhost:%d", buildscss.ActiveServerPort)
+					r.Host = "localhost"
+				},
+			}
+			logging.Debug().Msg("Redirecting esbuild SSE request to esbuild")
+			proxy.ServeHTTP(c.Res, c.Req)
+			res.hijacked = true
+			return res
+		}
+		return FourOhFour(c)
+	})
+
 	routes.GET(hmnurl.RegexPublic, func(c *RequestContext) ResponseData {
 		var res ResponseData
+		if buildscss.ActiveServerPort != 0 {
+			if strings.HasSuffix(c.Req.URL.Path, ".css") {
+				proxy := httputil.ReverseProxy{
+					Director: func(r *http.Request) {
+						r.URL.Scheme = "http"
+						r.URL.Host = fmt.Sprintf("localhost:%d", buildscss.ActiveServerPort)
+						r.Host = "localhost"
+					},
+					ModifyResponse: func(res *http.Response) error {
+						if res.StatusCode > 400 {
+							errStr, err := io.ReadAll(res.Body)
+							if err != nil {
+								return err
+							}
+							res.Body.Close()
+							logging.Error().Str("EsBuild error", string(errStr)).Msg("EsBuild is complaining")
+							res.Body = io.NopCloser(bytes.NewReader(errStr))
+						}
+						return nil
+					},
+				}
+				logging.Debug().Msg("Redirecting css request to esbuild")
+				proxy.ServeHTTP(c.Res, c.Req)
+				res.hijacked = true
+				return res
+			}
+		}
 		http.StripPrefix("/public/", http.FileServer(http.Dir("public"))).ServeHTTP(&res, c.Req)
 		addCORSHeaders(c, &res)
 		return res

src/website/website.go

@@ -12,6 +12,7 @@ import (
 
 	"git.handmade.network/hmn/hmn/src/assets"
 	"git.handmade.network/hmn/hmn/src/auth"
+	"git.handmade.network/hmn/hmn/src/buildscss"
 	"git.handmade.network/hmn/hmn/src/calendar"
 	"git.handmade.network/hmn/hmn/src/config"
 	"git.handmade.network/hmn/hmn/src/db"
@@ -54,6 +55,7 @@ var WebsiteCommand = &cobra.Command{
 			hmns3.StartServer(backgroundJobContext),
 			assets.BackgroundPreviewGeneration(backgroundJobContext, conn),
 			calendar.MonitorCalendars(backgroundJobContext),
+			buildscss.RunServer(backgroundJobContext),
 		)
 
 		signals := make(chan os.Signal, 1)
@@ -64,10 +66,10 @@ var WebsiteCommand = &cobra.Command{
 			go func() {
 				timeout, cancel := context.WithTimeout(context.Background(), 30*time.Second)
 				defer cancel()
-				logging.Info().Msg("shutting down web server")
-				server.Shutdown(timeout)
 				logging.Info().Msg("cancelling background jobs")
 				cancelBackgroundJobs()
+				logging.Info().Msg("shutting down web server")
+				server.Shutdown(timeout)
 			}()
 
 			<-signals