internal: replace esbuild api.Build with api.BuildContext

Using api.BuildContext [1] is more efficient than building again because
some of the data from the previous build is cached and can be reused
if the original files haven't changed since the previous build.

While at it, we update the github.com/evanw/esbuild module to latest
release.

[1] https://esbuild.github.io/api/#rebuild

3 files changed, 56 insertions, 29 deletions

diff --git a/go.mod b/go.mod
index 0d1a174..026fa16 100644
--- a/go.mod
+++ b/go.mod
@@ -7,7 +7,7 @@ go 1.20
 
 require (
 	git.sr.ht/~shulhan/ciigo v0.10.0
-	github.com/evanw/esbuild v0.19.3
+	github.com/evanw/esbuild v0.19.4
 	github.com/shuLhan/share v0.49.2-0.20230927031716-fa2510a8d458
 )
 
diff --git a/go.sum b/go.sum
index 3b9152c..98858fd 100644
--- a/go.sum
+++ b/go.sum
@@ -2,8 +2,8 @@ git.sr.ht/~shulhan/asciidoctor-go v0.5.0 h1:TfcAjv+7EwBZ83ef8OhX9vfQ4vRFcaJh0P1X
 git.sr.ht/~shulhan/asciidoctor-go v0.5.0/go.mod h1:RHAfgO1CU1It8Gsz6eqDBi8HhT4wxhCS1dKO8U9vIgM=
 git.sr.ht/~shulhan/ciigo v0.10.0 h1:s1SJ3/NzBcbOLmEZ4z1Cx9Vf7ZdDIvm45b7KMCZKzEY=
 git.sr.ht/~shulhan/ciigo v0.10.0/go.mod h1:cG6av+ywJZZp96F43kmLB2QWjm2hYiahbsbeTX/vlgk=
-github.com/evanw/esbuild v0.19.3 h1:foPr0xwQM3lBWKBtscauTN9FrmJzRDVI2+EGOs82H/I=
-github.com/evanw/esbuild v0.19.3/go.mod h1:iINY06rn799hi48UqEnaQvVfZWe6W9bET78LbvN8VWk=
+github.com/evanw/esbuild v0.19.4 h1:Etk+6ZCjtNxZZLEgMKSqpO0/oM0k1WYKJabaPMJ39iQ=
+github.com/evanw/esbuild v0.19.4/go.mod h1:iINY06rn799hi48UqEnaQvVfZWe6W9bET78LbvN8VWk=
 github.com/shuLhan/share v0.49.2-0.20230927031716-fa2510a8d458 h1:TqZptxsESZGZJbSWDVVUwIrGzvF4ZdgSz5WLOZH+Yrk=
 github.com/shuLhan/share v0.49.2-0.20230927031716-fa2510a8d458/go.mod h1:YEwLUwwBpDqPn5yxfdb0B8eFP04SKQxv5gMQwB4A+c4=
 github.com/yuin/goldmark v1.5.6 h1:COmQAWTCcGetChm3Ig7G/t8AFAN00t+o8Mt4cf7JpwA=
diff --git a/internal/internal.go b/internal/internal.go
index f14029d..38da779 100644
--- a/internal/internal.go
+++ b/internal/internal.go
@@ -10,6 +10,7 @@ import (
 
 	"git.sr.ht/~shulhan/ciigo"
 	"github.com/evanw/esbuild/pkg/api"
+	esapi "github.com/evanw/esbuild/pkg/api"
 	"github.com/shuLhan/share/lib/memfs"
 	"github.com/shuLhan/share/lib/mlog"
 )
@@ -25,9 +26,20 @@ var MemfsWww *memfs.MemFS
 // Build compile all TypeScript files inside _www into JavaScript and embed
 // them into memfs_www.go.
 func Build() (err error) {
-	var logp = `Build`
+	var (
+		logp = `Build`
+
+		esctx esapi.BuildContext
+	)
 
-	err = buildTypeScript(nil)
+	esctx, err = newEsbuild()
+	if err != nil {
+		return fmt.Errorf(`%s: %w`, logp, err)
+	}
+
+	defer esctx.Dispose()
+
+	err = buildTypeScript(esctx)
 	if err != nil {
 		return fmt.Errorf(`%s: %w`, logp, err)
 	}
@@ -72,6 +84,15 @@ func Watch() {
 		log.Fatalf(`%s: %s`, logp, err)
 	}
 
+	var esctx esapi.BuildContext
+
+	esctx, err = newEsbuild()
+	if err != nil {
+		log.Fatalf(`%s: %s`, logp, err)
+	}
+
+	defer esctx.Dispose()
+
 	if MemfsWww == nil {
 		err = initMemfsWww()
 		if err != nil {
@@ -93,20 +114,13 @@ func Watch() {
 	}
 
 	var (
-		buildTicker    = time.NewTicker(3 * time.Second)
-		esBuildOptions = api.BuildOptions{
-			EntryPoints: []string{`_www/main.ts`},
-			Platform:    api.PlatformBrowser,
-			Outfile:     `_www/main.js`,
-			GlobalName:  `awwan`,
-			Bundle:      true,
-			Write:       true,
-		}
+		buildTicker = time.NewTicker(3 * time.Second)
 
 		ns         memfs.NodeState
 		tsCount    int
 		embedCount int
 	)
+
 	for {
 		select {
 		case ns = <-dw.C:
@@ -141,7 +155,7 @@ func Watch() {
 
 		case <-buildTicker.C:
 			if tsCount > 0 {
-				err = buildTypeScript(&esBuildOptions)
+				err = buildTypeScript(esctx)
 				if err != nil {
 					mlog.Errf(`%s`, err)
 				} else {
@@ -161,27 +175,16 @@ func Watch() {
 	}
 }
 
-func buildTypeScript(esBuildOptions *api.BuildOptions) (err error) {
+func buildTypeScript(esctx esapi.BuildContext) (err error) {
 	var logp = `buildTypeScript`
 
-	if esBuildOptions == nil {
-		esBuildOptions = &api.BuildOptions{
-			EntryPoints: []string{`_www/main.ts`},
-			Platform:    api.PlatformBrowser,
-			Outfile:     `_www/main.js`,
-			GlobalName:  `app`,
-			Bundle:      true,
-			Write:       true,
-		}
-	}
-
-	var buildResult = api.Build(*esBuildOptions)
+	var buildResult = esctx.Rebuild()
 	if len(buildResult.Errors) == 0 {
 		return nil
 	}
 
 	var (
-		msg api.Message
+		msg esapi.Message
 		x   int
 	)
 	for x, msg = range buildResult.Errors {
@@ -234,3 +237,27 @@ func initMemfsWww() (err error) {
 	}
 	return nil
 }
+
+// newEsbuild create new [esapi.BuildContext] for transpiling TypeScript with
+// esbuild.
+func newEsbuild() (esctx api.BuildContext, err error) {
+	var (
+		esBuildOptions = esapi.BuildOptions{
+			EntryPoints: []string{`_www/main.ts`},
+			Platform:    esapi.PlatformBrowser,
+			Outfile:     `_www/main.js`,
+			GlobalName:  `awwan`,
+			Bundle:      true,
+			Write:       true,
+		}
+
+		errctx *esapi.ContextError
+	)
+
+	esctx, errctx = esapi.Context(esBuildOptions)
+	if errctx != nil {
+		return nil, fmt.Errorf(`newEsbuild: %w`, errctx)
+	}
+
+	return esctx, nil
+}