refactor(web): move embed package to web/ so go:embed reaches build/

go:embed paths are relative to the source file and cannot reach parent directories, so internal/web/embed.go could not see web/build/ without duplicating the placeholder. Relocating to web/embed.go lets the directive resolve to the real SvelteKit build output with no copy step.
2026-04-22 10:29:31 -04:00
parent d5692a73ca
commit 8fe4a5f578
18 changed files with 0 additions and 31 deletions
@@ -0,0 +1,61 @@
+// Package web embeds the SvelteKit SPA build output and serves it over HTTP.
+// Requests for real files under build/ are served verbatim; anything else —
+// deep links like /artists/abc, missing asset paths — returns build/index.html
+// so the SPA can resolve the route client-side.
+package web
+
+import (
+	"embed"
+	"io/fs"
+	"net/http"
+	"path"
+	"strings"
+)
+
+//go:embed all:build
+var buildFS embed.FS
+
+// Handler returns an http.Handler that serves the embedded SPA.
+//
+// Behavior:
+//   - GET /                              -> build/index.html
+//   - GET /<path that exists in build/>  -> that file, via http.FileServer
+//   - GET /<anything else>               -> build/index.html (SPA fallback)
+//
+// Callers are expected to register this as the router's NotFound/catch-all so
+// explicitly-routed paths (like /api/* and /rest/*) take precedence.
+func Handler() http.Handler {
+	sub, err := fs.Sub(buildFS, "build")
+	if err != nil {
+		// fs.Sub on a valid embed path can only fail if the embed directive
+		// is malformed, which the compile would have caught.
+		panic("web: fs.Sub(build) failed: " + err.Error())
+	}
+
+	index, err := fs.ReadFile(sub, "index.html")
+	if err != nil {
+		panic("web: embedded build/index.html missing: " + err.Error())
+	}
+
+	fileServer := http.FileServer(http.FS(sub))
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		clean := path.Clean(r.URL.Path)
+		if clean == "/" || clean == "." {
+			serveIndex(w, index)
+			return
+		}
+		name := strings.TrimPrefix(clean, "/")
+		if info, err := fs.Stat(sub, name); err == nil && !info.IsDir() {
+			fileServer.ServeHTTP(w, r)
+			return
+		}
+		serveIndex(w, index)
+	})
+}
+
+func serveIndex(w http.ResponseWriter, index []byte) {
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	w.Header().Set("Cache-Control", "no-cache")
+	_, _ = w.Write(index)
+}
@@ -0,0 +1,52 @@
+package web
+
+import (
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func TestHandler_ServesIndexAtRoot(t *testing.T) {
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+	rec := httptest.NewRecorder()
+	Handler().ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200", rec.Code)
+	}
+	if ct := rec.Header().Get("Content-Type"); !strings.Contains(ct, "text/html") {
+		t.Errorf("Content-Type = %q, want text/html*", ct)
+	}
+	body, _ := io.ReadAll(rec.Body)
+	if !strings.Contains(strings.ToLower(string(body)), "<html") {
+		t.Errorf("body missing <html tag; got: %q", string(body))
+	}
+}
+
+func TestHandler_UnknownPathFallsBackToIndex(t *testing.T) {
+	req := httptest.NewRequest(http.MethodGet, "/artists/some-uuid", nil)
+	rec := httptest.NewRecorder()
+	Handler().ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200 (SPA fallback)", rec.Code)
+	}
+	if ct := rec.Header().Get("Content-Type"); !strings.Contains(ct, "text/html") {
+		t.Errorf("Content-Type = %q, want text/html* for SPA fallback", ct)
+	}
+}
+
+func TestHandler_MissingAssetFallsBackToIndex(t *testing.T) {
+	req := httptest.NewRequest(http.MethodGet, "/_app/immutable/chunks/does-not-exist.js", nil)
+	rec := httptest.NewRecorder()
+	Handler().ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusOK {
+		t.Fatalf("status = %d, want 200 (fallback to index.html)", rec.Code)
+	}
+	if ct := rec.Header().Get("Content-Type"); !strings.Contains(ct, "text/html") {
+		t.Errorf("Content-Type = %q, want text/html* for missing asset", ct)
+	}
+}