Installable as an app (PWA): manifests, offline-only service worker, icons

internal/web/pwa_test.go

@@ -0,0 +1,46 @@
+package web
+
+import (
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func TestPWA(t *testing.T) {
+	h := (&Server{site: defaultSite()}).Handler()
+	get := func(path string) *httptest.ResponseRecorder {
+		rec := httptest.NewRecorder()
+		h.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, path, nil))
+		if rec.Code != http.StatusOK {
+			t.Fatalf("%s: status %d", path, rec.Code)
+		}
+		return rec
+	}
+
+	for path, start := range map[string]string{"/manifest.webmanifest": "/", "/admin.webmanifest": "/admin"} {
+		rec := get(path)
+		if ct := rec.Header().Get("Content-Type"); ct != "application/manifest+json" {
+			t.Errorf("%s: content type %q", path, ct)
+		}
+		var m manifest
+		if err := json.Unmarshal(rec.Body.Bytes(), &m); err != nil {
+			t.Fatalf("%s: %v", path, err)
+		}
+		if m.StartURL != start || m.ID != start || m.Scope != "/" || m.Display != "standalone" {
+			t.Errorf("%s: %+v", path, m)
+		}
+		// Every icon must exist, or Chrome won't offer to install.
+		for _, icon := range m.Icons {
+			if ct := get(icon.Src).Header().Get("Content-Type"); ct != icon.Type {
+				t.Errorf("%s: %s is %q, manifest says %q", path, icon.Src, ct, icon.Type)
+			}
+		}
+	}
+
+	if ct := get("/sw.js").Header().Get("Content-Type"); !strings.HasPrefix(ct, "text/javascript") {
+		t.Errorf("/sw.js: content type %q", ct)
+	}
+	get("/static/offline.html")
+}