Feature 01 task 3: Embed the PWA build with SPA fallback (#4)

Co-authored-by: dev_agent <dev_agent@cubecraftlabs.com> Co-committed-by: dev_agent <dev_agent@cubecraftlabs.com>
2026-10-02 22:47:01 -04:00
parent f0b2696059
commit 85569b451f
8 changed files with 451 additions and 21 deletions
@@ -3,20 +3,44 @@ package server

 import (
 	"encoding/json"
+	"io/fs"
 	"log/slog"
 	"net/http"

 	"github.com/go-chi/chi/v5"
+
+	"code.cubecraftlabs.com/Maniacs_Mansion/Meal-Quest/internal/frontend"
 )

+// reservedPrefixes are owned by the API router and are never answered with the
+// SPA's index.html.
+var reservedPrefixes = []string{"/api", "/auth", "/media", "/health"}
+
 // NewRouter returns the HTTP handler for the service. version is reported by
-// GET /health.
-func NewRouter(logger *slog.Logger, version string) http.Handler {
+// GET /health; assets is the web build served for every other GET.
+func NewRouter(logger *slog.Logger, version string, assets fs.FS) (http.Handler, error) {
+	notFound := apiErrorHandler(logger, http.StatusNotFound, "not_found", "not found")
+	methodNotAllowed := apiErrorHandler(logger, http.StatusMethodNotAllowed, "method_not_allowed", "method not allowed")
+
+	web, err := frontend.NewHandler(assets, logger, notFound, reservedPrefixes...)
+	if err != nil {
+		return nil, err
+	}
+
 	r := chi.NewRouter()
+	r.MethodNotAllowed(methodNotAllowed)
+	r.NotFound(notFound)
+
 	r.Get("/health", health(logger, version))
-	r.MethodNotAllowed(apiErrorHandler(logger, http.StatusMethodNotAllowed, "method_not_allowed", "method not allowed"))
-	r.NotFound(apiErrorHandler(logger, http.StatusNotFound, "not_found", "not found"))
-	return r
+	r.Route("/api", func(r chi.Router) {
+		r.MethodNotAllowed(methodNotAllowed)
+		r.NotFound(notFound)
+	})
+	// Catch-all for the PWA. /auth and /media have no routes yet; the frontend
+	// handler passes them to notFound rather than the SPA fallback.
+	r.Method(http.MethodGet, "/*", web)
+	r.Method(http.MethodHead, "/*", web)
+	return r, nil
 }

 type errorBody struct {
@@ -7,14 +7,35 @@ import (
 	"maps"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
+	"testing/fstest"
 )

+const (
+	fixtureIndex = "<!doctype html><title>fixture index</title>"
+	fixtureAsset = "console.log('fixture asset')"
+	notFoundJSON = `{"error":{"code":"not_found","message":"not found","retryable":false}}`
+)
+
+func newTestRouter(t *testing.T, version string) http.Handler {
+	t.Helper()
+	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
+	assets := fstest.MapFS{
+		"index.html":             {Data: []byte(fixtureIndex)},
+		"assets/index-AbC123.js": {Data: []byte(fixtureAsset)},
+	}
+	r, err := NewRouter(logger, version, assets)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return r
+}
+
 func TestHealth(t *testing.T) {
 	t.Parallel()

-	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
-	srv := httptest.NewServer(NewRouter(logger, "1.2.3"))
+	srv := httptest.NewServer(newTestRouter(t, "1.2.3"))
 	t.Cleanup(srv.Close)

 	resp, err := http.Get(srv.URL + "/health")
@@ -42,9 +63,8 @@ func TestHealth(t *testing.T) {
 func TestHealthRejectsOtherMethods(t *testing.T) {
 	t.Parallel()

-	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
 	rec := httptest.NewRecorder()
-	NewRouter(logger, "dev").ServeHTTP(rec, httptest.NewRequest(http.MethodPost, "/health", nil))
+	newTestRouter(t, "dev").ServeHTTP(rec, httptest.NewRequest(http.MethodPost, "/health", nil))

 	if rec.Code != http.StatusMethodNotAllowed {
 		t.Errorf("status = %d, want 405", rec.Code)
@@ -68,21 +88,98 @@ func TestHealthRejectsOtherMethods(t *testing.T) {
 	}
 }

-func TestUnknownPathNotFound(t *testing.T) {
+func TestReservedPathsNotFound(t *testing.T) {
 	t.Parallel()

-	logger := slog.New(slog.NewTextHandler(io.Discard, nil))
-	rec := httptest.NewRecorder()
-	NewRouter(logger, "dev").ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/unknown", nil))
+	router := newTestRouter(t, "dev")
+	tests := []struct {
+		method string
+		path   string
+	}{
+		{http.MethodGet, "/api"},
+		{http.MethodGet, "/api/unknown"},
+		{http.MethodPost, "/api/unknown"},
+		{http.MethodGet, "/auth/callback"},
+		{http.MethodGet, "/media/photo.jpg"},
+		{http.MethodGet, "/health/deep"},
+		{http.MethodGet, "/auth/../quests/42"},
+		{http.MethodGet, "/api%2F..%2Fquests/42"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.method+" "+tt.path, func(t *testing.T) {
+			t.Parallel()

-	if rec.Code != http.StatusNotFound {
-		t.Errorf("status = %d, want 404", rec.Code)
+			rec := httptest.NewRecorder()
+			router.ServeHTTP(rec, httptest.NewRequest(tt.method, tt.path, nil))
+
+			if rec.Code != http.StatusNotFound {
+				t.Errorf("status = %d, want 404", rec.Code)
+			}
+			if ct := rec.Header().Get("Content-Type"); ct != "application/json" {
+				t.Errorf("Content-Type = %q, want application/json", ct)
+			}
+			if got := rec.Body.String(); got != notFoundJSON {
+				t.Errorf("body = %s, want %s", got, notFoundJSON)
+			}
+		})
 	}
-	if ct := rec.Header().Get("Content-Type"); ct != "application/json" {
-		t.Errorf("Content-Type = %q, want application/json", ct)
+}
+
+func TestFrontend(t *testing.T) {
+	t.Parallel()
+
+	router := newTestRouter(t, "dev")
+	tests := []struct {
+		path      string
+		wantBody  string
+		wantCache string
+	}{
+		{"/", fixtureIndex, "no-cache"},
+		{"/assets/index-AbC123.js", fixtureAsset, "public, max-age=31536000, immutable"},
+		{"/quests/42", fixtureIndex, "no-cache"},
+		{"/quests/42/edit", fixtureIndex, "no-cache"},
 	}
-	const want = `{"error":{"code":"not_found","message":"not found","retryable":false}}`
-	if got := rec.Body.String(); got != want {
-		t.Errorf("body = %s, want %s", got, want)
+	for _, tt := range tests {
+		t.Run(tt.path, func(t *testing.T) {
+			t.Parallel()
+
+			rec := httptest.NewRecorder()
+			router.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, tt.path, nil))
+
+			if rec.Code != http.StatusOK {
+				t.Errorf("status = %d, want 200", rec.Code)
+			}
+			if got := rec.Body.String(); got != tt.wantBody {
+				t.Errorf("body = %q, want %q", got, tt.wantBody)
+			}
+			if got := rec.Header().Get("Cache-Control"); got != tt.wantCache {
+				t.Errorf("Cache-Control = %q, want %q", got, tt.wantCache)
+			}
+		})
+	}
+}
+
+func TestHealthNotShadowed(t *testing.T) {
+	t.Parallel()
+
+	rec := httptest.NewRecorder()
+	newTestRouter(t, "dev").ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/health", nil))
+
+	if body := rec.Body.String(); rec.Code != http.StatusOK || strings.Contains(body, fixtureIndex) {
+		t.Errorf("GET /health = %d %q, want 200 health JSON", rec.Code, body)
+	}
+}
+
+func TestFrontendRejectsOtherMethods(t *testing.T) {
+	t.Parallel()
+
+	rec := httptest.NewRecorder()
+	newTestRouter(t, "dev").ServeHTTP(rec, httptest.NewRequest(http.MethodPost, "/quests/42", nil))
+
+	if rec.Code != http.StatusMethodNotAllowed {
+		t.Errorf("status = %d, want 405", rec.Code)
+	}
+	if strings.Contains(rec.Body.String(), fixtureIndex) {
+		t.Errorf("body = %q, want no index.html", rec.Body.String())
 	}
 }