From 11bdd9751b860ba0c3b740a3e51114597b17229c Mon Sep 17 00:00:00 2001
From: mkelvers <mikkelelvers@outlook.com>
Date: Fri, 3 Jul 2026 16:16:12 +0200
Subject: [PATCH] test: add manifest icon and first-load asset size validation

---
 templates/brand_assets_test.go | 118 +++++++++++++++++++++++++++++++++
 1 file changed, 118 insertions(+)
 create mode 100644 templates/brand_assets_test.go

diff --git a/templates/brand_assets_test.go b/templates/brand_assets_test.go
new file mode 100644
index 00000000..46ddeb52
--- /dev/null
+++ b/templates/brand_assets_test.go
@@ -0,0 +1,118 @@
+package templates
+
+import (
+	"encoding/json"
+	"image/png"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"testing"
+)
+
+type manifestIcon struct {
+	Src   string `json:"src"`
+	Sizes string `json:"sizes"`
+}
+
+func TestManifestIconDimensions(t *testing.T) {
+	data, err := os.ReadFile("../static/assets/manifest.json")
+	if err != nil {
+		t.Fatalf("read manifest: %v", err)
+	}
+
+	var manifest struct {
+		Icons []manifestIcon `json:"icons"`
+	}
+	if err := json.Unmarshal(data, &manifest); err != nil {
+		t.Fatalf("parse manifest: %v", err)
+	}
+	if len(manifest.Icons) == 0 {
+		t.Fatal("manifest has no icons")
+	}
+
+	for _, icon := range manifest.Icons {
+		t.Run(icon.Sizes, func(t *testing.T) {
+			width, height := parseIconSize(t, icon.Sizes)
+			assetURL, err := url.Parse(icon.Src)
+			if err != nil {
+				t.Fatalf("parse icon URL: %v", err)
+			}
+			if assetURL.Query().Get("v") == "" {
+				t.Fatalf("icon URL is not versioned: %q", icon.Src)
+			}
+
+			file, err := os.Open(filepath.Join("..", strings.TrimPrefix(assetURL.Path, "/")))
+			if err != nil {
+				t.Fatalf("open icon: %v", err)
+			}
+			defer file.Close()
+
+			config, err := png.DecodeConfig(file)
+			if err != nil {
+				t.Fatalf("decode icon: %v", err)
+			}
+			if config.Width != width || config.Height != height {
+				t.Fatalf("icon dimensions = %dx%d, manifest declares %s", config.Width, config.Height, icon.Sizes)
+			}
+		})
+	}
+}
+
+func TestFirstLoadBrandAssetSizes(t *testing.T) {
+	tests := []struct {
+		name     string
+		path     string
+		width    int
+		height   int
+		maxBytes int64
+	}{
+		{name: "navigation logo", path: "../static/assets/logo-128.png", width: 166, height: 128, maxBytes: 25 * 1024},
+		{name: "32px favicon", path: "../static/assets/favicon-32.png", width: 32, height: 32, maxBytes: 20 * 1024},
+		{name: "16px favicon", path: "../static/assets/favicon-16.png", width: 16, height: 16, maxBytes: 20 * 1024},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			file, err := os.Open(tt.path)
+			if err != nil {
+				t.Fatalf("open asset: %v", err)
+			}
+			defer file.Close()
+
+			info, err := file.Stat()
+			if err != nil {
+				t.Fatalf("stat asset: %v", err)
+			}
+			if info.Size() > tt.maxBytes {
+				t.Fatalf("asset size = %d bytes, max %d", info.Size(), tt.maxBytes)
+			}
+
+			config, err := png.DecodeConfig(file)
+			if err != nil {
+				t.Fatalf("decode asset: %v", err)
+			}
+			if config.Width != tt.width || config.Height != tt.height {
+				t.Fatalf("asset dimensions = %dx%d, want %dx%d", config.Width, config.Height, tt.width, tt.height)
+			}
+		})
+	}
+}
+
+func parseIconSize(t *testing.T, value string) (int, int) {
+	t.Helper()
+	widthValue, heightValue, ok := strings.Cut(value, "x")
+	if !ok {
+		t.Fatalf("invalid icon size %q", value)
+	}
+	width, err := strconv.Atoi(widthValue)
+	if err != nil {
+		t.Fatalf("parse icon width: %v", err)
+	}
+	height, err := strconv.Atoi(heightValue)
+	if err != nil {
+		t.Fatalf("parse icon height: %v", err)
+	}
+	return width, height
+}