Add js web stuff to landing page + documentation

go/jsbundler/genroutes.go

@@ -0,0 +1,138 @@
+package jsbundler
+
+// Public-route code generation.  The single source of truth is the TypeScript
+// manifest frontend/src/pages/public/pages.ts.  This reads it (via esbuild +
+// goja, so it's real evaluation, not fragile text parsing) and generates:
+//
+//   - internal/handlers/public_pages.gen.go    Go registry: routes + <title> +
+//     the page's pre-rendered body (baked here, see genssr.go: writeGoRegistry)
+//   - frontend/src/pages/public/routes.gen.ts  client router maps: route → body
+//     component (publicRoutes) and route → <title> (publicTitles)
+//
+// Generated files are committed like the other build artifacts; regenerate by
+// running the bundler.
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/dop251/goja"
+	esbuild "github.com/evanw/esbuild/pkg/api"
+)
+
+const pagesManifest = "src/pages/public/pages.ts" // relative to frontendDir
+
+type pageDef struct {
+	Path      string `json:"path"`
+	Module    string `json:"module"` // relative to frontend/src
+	Component string `json:"component"`
+	Title     string `json:"title"`
+	Dynamic   bool   `json:"dynamic"` // ISR page: also bake its render JS for request-time data rendering
+}
+
+func generatePublicRoutes() error {
+	defs, err := loadPageDefs()
+	if err != nil {
+		return fmt.Errorf("loading page manifest: %w", err)
+	}
+	if err := writeGoRegistry(defs); err != nil {
+		return fmt.Errorf("writing Go registry: %w", err)
+	}
+	if err := writeClientRoutes(defs); err != nil {
+		return fmt.Errorf("writing client routes: %w", err)
+	}
+	fmt.Printf("  Public routes: %d page(s) generated\n", len(defs))
+	return nil
+}
+
+// loadPageDefs bundles and evaluates the TS manifest to get the page list.
+func loadPageDefs() ([]pageDef, error) {
+	absCwd, err := filepath.Abs(".")
+	if err != nil {
+		return nil, err
+	}
+	pagesAbs := filepath.ToSlash(filepath.Join(absCwd, frontendDir, pagesManifest))
+	entry := fmt.Sprintf("import { publicPages } from %q;\nglobalThis.__PAGES__ = JSON.stringify(publicPages);", pagesAbs)
+
+	res := esbuild.Build(esbuild.BuildOptions{
+		Stdin: &esbuild.StdinOptions{
+			Contents:   entry,
+			ResolveDir: absCwd,
+			Sourcefile: "pages-manifest.js",
+			Loader:     esbuild.LoaderTS,
+		},
+		Bundle:   true,
+		Format:   esbuild.FormatIIFE,
+		Target:   esbuild.ES2017,
+		Platform: esbuild.PlatformNeutral,
+		LogLevel: esbuild.LogLevelSilent,
+		Write:    false,
+	})
+	if len(res.Errors) > 0 {
+		msgs := esbuild.FormatMessages(res.Errors, esbuild.FormatMessagesOptions{})
+		return nil, fmt.Errorf("esbuild: %s", strings.Join(msgs, "\n"))
+	}
+
+	vm := goja.New()
+	if _, err := vm.RunString(string(res.OutputFiles[0].Contents)); err != nil {
+		return nil, err
+	}
+	raw := vm.Get("__PAGES__")
+	if raw == nil {
+		return nil, fmt.Errorf("manifest did not export publicPages")
+	}
+	var defs []pageDef
+	if err := json.Unmarshal([]byte(raw.String()), &defs); err != nil {
+		return nil, err
+	}
+	return defs, nil
+}
+
+// goRoute maps a URL pathname to a Go ServeMux pattern. Root needs "/{$}" so
+// it matches exactly instead of as a catch-all subtree.
+func goRoute(pathname string) string {
+	if pathname == "/" {
+		return "/{$}"
+	}
+	return pathname
+}
+
+func writeClientRoutes(defs []pageDef) error {
+	// Dedupe imports by component name (a component may back several routes).
+	seen := map[string]bool{}
+	var imports, entries, titles strings.Builder
+	for _, d := range defs {
+		if !seen[d.Component] {
+			seen[d.Component] = true
+			rel, err := filepath.Rel("pages/public", filepath.FromSlash(d.Module))
+			if err != nil {
+				return err
+			}
+			imp := "./" + filepath.ToSlash(rel)
+			fmt.Fprintf(&imports, "import { %s } from %q;\n", d.Component, imp)
+		}
+		fmt.Fprintf(&entries, "    %q: %s,\n", d.Path, d.Component)
+		fmt.Fprintf(&titles, "    %q: %q,\n", d.Path, d.Title)
+	}
+
+	var b strings.Builder
+	b.WriteString("// Code generated by cmd/bundle; DO NOT EDIT.\n")
+	b.WriteString("// Source: frontend/src/pages/public/pages.ts\n\n")
+	b.WriteString("import { JSXElement } from \"solid-js\";\n")
+	b.WriteString(imports.String())
+	b.WriteString("\n// Body component for each public route, keyed by URL pathname. The client\n")
+	b.WriteString("// router (public.ts) renders these when navigating without a full reload.\n")
+	b.WriteString("export const publicRoutes: Record<string, () => JSXElement> = {\n")
+	b.WriteString(entries.String())
+	b.WriteString("};\n")
+	b.WriteString("\n// <title> for each public route, applied by the client router on navigation\n")
+	b.WriteString("// (the first load gets its title from the server-rendered shell).\n")
+	b.WriteString("export const publicTitles: Record<string, string> = {\n")
+	b.WriteString(titles.String())
+	b.WriteString("};\n")
+
+	return os.WriteFile(filepath.Join(frontendDir, "src", "pages", "public", "routes.gen.ts"), []byte(b.String()), 0644)
+}