package/viewer: design viewer API and port svelte's SSR rendering over

go.mod

@@ -18,6 +18,7 @@ require (
 	github.com/keegancsmith/rpc v1.3.0
 	github.com/lithammer/dedent v1.1.0
 	github.com/livebud/bud-test-plugin v0.0.9
+	github.com/livebud/js v0.0.0-20221112072017-b9e63b92aad5
 	github.com/livebud/transpiler v0.0.1
 	github.com/matthewmueller/diff v0.0.0-20220104030700-cb2fe910d90c
 	github.com/matthewmueller/gotext v0.0.0-20210424201144-265ed61725ac

go.sum

@@ -66,6 +66,8 @@ github.com/livebud/bud-test-nested-plugin v0.0.5 h1:MpPp20Gng0F+Kvl+L9kttu6nsJIY
 github.com/livebud/bud-test-nested-plugin v0.0.5/go.mod h1:M3QujkGG4ggZ6h75t5zF8MEJFrLTwa2USeIYHQdO2YQ=
 github.com/livebud/bud-test-plugin v0.0.9 h1:JmS4aj+NV52RUroteLs+ld6rcbkBwio7p9qPNutTsqM=
 github.com/livebud/bud-test-plugin v0.0.9/go.mod h1:GTxMZ8W4BIyGIOgAA4hvPHMDDTkaZtfcuhnOcSu3y8M=
+github.com/livebud/js v0.0.0-20221112072017-b9e63b92aad5 h1:7fYJMOnT4WrnjRhJ8B6HiJBGcDVFd9jam0205gn9y1k=
+github.com/livebud/js v0.0.0-20221112072017-b9e63b92aad5/go.mod h1:TDkks+mVAlB96mxcbIAftAxpGteCxoBYGVF1JThjcLk=
 github.com/livebud/transpiler v0.0.1 h1:raG4W8qMq534VYrWv5sFQieQCa4McrJhQOy0YXk63kk=
 github.com/livebud/transpiler v0.0.1/go.mod h1:vQYMN//Y2cnM55tw0lOmLGbEETugP7alxTyhQHzNdTI=
 github.com/matryer/is v1.4.0 h1:sosSmIWwkYITGrxZ25ULNDeKiMNzFSr4V/eqBQP0PeE=

internal/es/build.go

@@ -0,0 +1,94 @@
+package es
+
+import (
+	"fmt"
+	"io/fs"
+	"strings"
+
+	esbuild "github.com/evanw/esbuild/pkg/api"
+)
+
+// TODO: replace with *gomod.Module
+func New(absDir string) *Builder {
+	return &Builder{
+		dir: absDir,
+		base: esbuild.BuildOptions{
+			AbsWorkingDir: absDir,
+			Outdir:        "./",
+			Format:        esbuild.FormatIIFE,
+			Platform:      esbuild.PlatformBrowser,
+			GlobalName:    "bud",
+			Bundle:        true,
+			Plugins: []esbuild.Plugin{
+				httpPlugin(absDir),
+				esmPlugin(absDir),
+			},
+		},
+	}
+}
+
+type Builder struct {
+	dir  string
+	base esbuild.BuildOptions
+}
+
+func (b *Builder) Directory() string {
+	return b.dir
+}
+
+type Entrypoint = esbuild.EntryPoint
+type Plugin = esbuild.Plugin
+
+type Build struct {
+	Entrypoint string
+	Plugins    []Plugin
+	Minify     bool
+}
+
+func (b *Builder) Build(build *Build) ([]byte, error) {
+	input := esbuild.BuildOptions{
+		EntryPointsAdvanced: []esbuild.EntryPoint{
+			{
+				InputPath:  build.Entrypoint,
+				OutputPath: build.Entrypoint,
+			},
+		},
+		AbsWorkingDir: b.base.AbsWorkingDir,
+		Outdir:        b.base.Outdir,
+		Format:        b.base.Format,
+		Platform:      b.base.Platform,
+		GlobalName:    b.base.GlobalName,
+		Bundle:        b.base.Bundle,
+		Metafile:      b.base.Metafile,
+		Plugins:       append(build.Plugins, b.base.Plugins...),
+	}
+	if build.Minify {
+		input.MinifyWhitespace = true
+		input.MinifyIdentifiers = true
+		input.MinifySyntax = true
+	}
+	result := esbuild.Build(input)
+	if len(result.Errors) > 0 {
+		msgs := esbuild.FormatMessages(result.Errors, esbuild.FormatMessagesOptions{
+			Color: true,
+			Kind:  esbuild.ErrorMessage,
+		})
+		return nil, fmt.Errorf(strings.Join(msgs, "\n"))
+	}
+	// Expect exactly 1 output file
+	if len(result.OutputFiles) != 1 {
+		return nil, fmt.Errorf("expected exactly 1 output file but got %d", len(result.OutputFiles))
+	}
+	ssrCode := result.OutputFiles[0].Contents
+	return ssrCode, nil
+}
+
+type Bundle struct {
+	Entrypoints []string
+	Plugins     []Plugin
+	Minify      bool
+}
+
+func (b *Builder) Bundle(out fs.FS, bundle *Bundle) error {
+	return nil
+}

internal/es/plugins.go

@@ -0,0 +1,66 @@
+package es
+
+import (
+	"io"
+	"net/http"
+
+	esbuild "github.com/evanw/esbuild/pkg/api"
+)
+
+func httpPlugin(absDir string) esbuild.Plugin {
+	return esbuild.Plugin{
+		Name: "bud-http",
+		Setup: func(epb esbuild.PluginBuild) {
+			epb.OnResolve(esbuild.OnResolveOptions{Filter: `^http[s]?://`}, func(args esbuild.OnResolveArgs) (result esbuild.OnResolveResult, err error) {
+				result.Namespace = "http"
+				result.Path = args.Path
+				return result, nil
+			})
+			epb.OnLoad(esbuild.OnLoadOptions{Filter: `.*`, Namespace: `http`}, func(args esbuild.OnLoadArgs) (result esbuild.OnLoadResult, err error) {
+				res, err := http.Get(args.Path)
+				if err != nil {
+					return result, err
+				}
+				defer res.Body.Close()
+				body, err := io.ReadAll(res.Body)
+				if err != nil {
+					return result, err
+				}
+				contents := string(body)
+				result.ResolveDir = absDir
+				result.Contents = &contents
+				result.Loader = esbuild.LoaderJS
+				return result, nil
+			})
+		},
+	}
+}
+
+func esmPlugin(absDir string) esbuild.Plugin {
+	return esbuild.Plugin{
+		Name: "bud-esm",
+		Setup: func(epb esbuild.PluginBuild) {
+			epb.OnResolve(esbuild.OnResolveOptions{Filter: `^[a-z0-9@]`}, func(args esbuild.OnResolveArgs) (result esbuild.OnResolveResult, err error) {
+				result.Namespace = "esm"
+				result.Path = args.Path
+				return result, nil
+			})
+			epb.OnLoad(esbuild.OnLoadOptions{Filter: `.*`, Namespace: `esm`}, func(args esbuild.OnLoadArgs) (result esbuild.OnLoadResult, err error) {
+				res, err := http.Get("https://esm.sh/" + args.Path)
+				if err != nil {
+					return result, err
+				}
+				defer res.Body.Close()
+				body, err := io.ReadAll(res.Body)
+				if err != nil {
+					return result, err
+				}
+				contents := string(body)
+				result.ResolveDir = absDir
+				result.Contents = &contents
+				result.Loader = esbuild.LoaderJS
+				return result, nil
+			})
+		},
+	}
+}

package/viewer/find.go

@@ -0,0 +1,100 @@
+package viewer
+
+import (
+	"io/fs"
+	"path"
+	"path/filepath"
+)
+
+type Pages = map[Key]*Page
+
+// Find pages
+func Find(fsys fs.FS) (Pages, error) {
+	pages := make(Pages)
+	inherited := &inherited{
+		Layout: make(map[ext]*View),
+		Frames: make(map[ext][]*View),
+		Error:  make(map[ext]*View),
+	}
+	if err := find(fsys, pages, inherited, "."); err != nil {
+		return nil, err
+	}
+	return pages, nil
+}
+
+type ext = string
+
+type inherited struct {
+	Layout map[ext]*View
+	Frames map[ext][]*View
+	Error  map[ext]*View
+}
+
+func find(fsys fs.FS, pages Pages, inherited *inherited, dir string) error {
+	des, err := fs.ReadDir(fsys, dir)
+	if err != nil {
+		return err
+	}
+
+	// First pass: look for layouts, frames and errors
+	for _, de := range des {
+		if de.IsDir() {
+			continue
+		}
+		ext := filepath.Ext(de.Name())
+		extless := de.Name()[:len(de.Name())-len(ext)]
+		switch extless {
+		case "layout":
+			inherited.Layout[ext] = &View{
+				Path: path.Join(dir, de.Name()),
+				Key:  path.Join(dir, extless),
+			}
+		case "frame":
+			inherited.Frames[ext] = append(inherited.Frames[ext], &View{
+				Path: path.Join(dir, de.Name()),
+				Key:  path.Join(dir, extless),
+			})
+		case "error":
+			inherited.Error[ext] = &View{
+				Path: path.Join(dir, de.Name()),
+				Key:  path.Join(dir, extless),
+			}
+		}
+	}
+
+	// Second pass: go through pages
+	for _, de := range des {
+		if de.IsDir() {
+			continue
+		}
+		ext := filepath.Ext(de.Name())
+		extless := de.Name()[:len(de.Name())-len(ext)]
+		switch extless {
+		case "layout", "frame", "error":
+			continue
+		default:
+			key := path.Join(dir, extless)
+			pages[key] = &Page{
+				View: &View{
+					Path: path.Join(dir, de.Name()),
+					Key:  key,
+				},
+				Layout: inherited.Layout[ext],
+				Frames: inherited.Frames[ext],
+				Error:  inherited.Error[ext],
+			}
+		}
+	}
+
+	// Third pass: go through directories
+	for _, de := range des {
+		if !de.IsDir() {
+			continue
+		}
+		if err := find(fsys, pages, inherited, de.Name()); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

package/viewer/find_test.go

@@ -0,0 +1,57 @@
+package viewer_test
+
+import (
+	"fmt"
+	"testing"
+	"testing/fstest"
+
+	"github.com/livebud/bud/internal/is"
+	"github.com/livebud/bud/package/viewer"
+)
+
+func TestIndex(t *testing.T) {
+	is := is.New(t)
+	fsys := fstest.MapFS{
+		"index.gohtml": &fstest.MapFile{Data: []byte("Hello {{ .Planet }}!")},
+	}
+	// Find the pages
+	pages, err := viewer.Find(fsys)
+	is.NoErr(err)
+	is.Equal(len(pages), 1)
+	is.True(pages["index"] != nil)
+	is.Equal(pages["index"].Path, "index.gohtml")
+	is.Equal(len(pages["index"].Frames), 0)
+	is.Equal(pages["index"].Layout, nil)
+	is.Equal(pages["index"].Error, nil)
+}
+
+func TestNested(t *testing.T) {
+	is := is.New(t)
+	fsys := fstest.MapFS{
+		"layout.svelte":      &fstest.MapFile{Data: []byte(`<slot />`)},
+		"frame.svelte":       &fstest.MapFile{Data: []byte(`<slot />`)},
+		"posts/frame.svelte": &fstest.MapFile{Data: []byte(`<slot />`)},
+		"posts/index.svelte": &fstest.MapFile{Data: []byte(`<h1>Hello {planet}!</h1>`)},
+	}
+	// Find the pages
+	pages, err := viewer.Find(fsys)
+	is.NoErr(err)
+	is.Equal(len(pages), 1)
+	fmt.Println(pages)
+	is.True(pages["posts/index"] != nil)
+	is.Equal(pages["posts/index"].Path, "posts/index.svelte")
+
+	// Frames
+	is.Equal(len(pages["posts/index"].Frames), 2)
+	is.Equal(pages["posts/index"].Frames[0].Key, "frame")
+	is.Equal(pages["posts/index"].Frames[0].Path, "frame.svelte")
+	is.Equal(pages["posts/index"].Frames[1].Key, "posts/frame")
+	is.Equal(pages["posts/index"].Frames[1].Path, "posts/frame.svelte")
+
+	is.Equal(pages["posts/index"].Error, nil)
+
+	// Layout
+	is.True(pages["posts/index"].Layout != nil)
+	is.Equal(pages["posts/index"].Layout.Key, "layout")
+	is.Equal(pages["posts/index"].Layout.Path, "layout.svelte")
+}

package/viewer/gohtml/gohtml.go

@@ -0,0 +1,60 @@
+package gohtml
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"html/template"
+	"io/fs"
+
+	"github.com/livebud/bud/package/viewer"
+	"github.com/livebud/bud/runtime/transpiler"
+)
+
+func New(fsys fs.FS, transpiler transpiler.Interface, pages viewer.Pages) *Viewer {
+	return &Viewer{fsys, pages, transpiler}
+}
+
+type Viewer struct {
+	fsys       fs.FS
+	pages      viewer.Pages
+	transpiler transpiler.Interface
+}
+
+var _ viewer.Viewer = (*Viewer)(nil)
+
+func (v *Viewer) Register(router viewer.Router) {
+	fmt.Println("register called")
+}
+
+func (v *Viewer) Render(ctx context.Context, key string, props viewer.Props) ([]byte, error) {
+	page, ok := v.pages[key]
+	if !ok {
+		return nil, fmt.Errorf("gohtml: %q. %w", key, viewer.ErrPageNotFound)
+	}
+	entryCode, err := fs.ReadFile(v.fsys, page.Path)
+	if err != nil {
+		return nil, fmt.Errorf("gohtml: error reading %q. %w", page.Path, err)
+	}
+	entryCode, err = v.transpiler.Transpile(page.Path, ".gohtml", entryCode)
+	if err != nil {
+		return nil, fmt.Errorf("gohtml: error transpiling %q. %w", page.Path, err)
+	}
+	entryTemplate, err := template.New(page.Path).Parse(string(entryCode))
+	if err != nil {
+		return nil, fmt.Errorf("gohtml: error parsing %q. %w", page.Path, err)
+	}
+	entryHTML := new(bytes.Buffer)
+	if err := entryTemplate.Execute(entryHTML, props[page.Key]); err != nil {
+		return nil, fmt.Errorf("gohtml: error executing %q. %w", page.Path, err)
+	}
+	return entryHTML.Bytes(), nil
+}
+
+func (v *Viewer) RenderError(ctx context.Context, key string, err error, props viewer.Props) []byte {
+	return []byte("RenderError not implemented")
+}
+
+func (v *Viewer) Bundle(ctx context.Context, out viewer.FS) error {
+	return nil
+}