hub.MakeLink method to assure URLs are formatted properly (#805)

- Updated AlertManager to replace direct app references with a hub interface.
- Changed AlertManager.app to AlertManager.hub
- Add tests for MakeLink

beszel/internal/hub/hub.go

@@ -285,3 +285,16 @@ func (h *Hub) GetSSHKey() (ssh.Signer, error) {
 
 	return sshPrivate, err
 }
+
+// MakeLink formats a link with the app URL and path segments.
+// Only path segments should be provided.
+func (h *Hub) MakeLink(parts ...string) string {
+	base := strings.TrimSuffix(h.Settings().Meta.AppURL, "/")
+	for _, part := range parts {
+		if part == "" {
+			continue
+		}
+		base = fmt.Sprintf("%s/%s", base, url.PathEscape(part))
+	}
+	return base
+}

beszel/internal/hub/hub_test.go

@@ -0,0 +1,106 @@
+//go:build testing
+// +build testing
+
+package hub
+
+import (
+	"testing"
+
+	"github.com/pocketbase/pocketbase"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMakeLink(t *testing.T) {
+	// The Hub's MakeLink method uses h.Settings().Meta.AppURL.
+	// h.Settings() is a method on h.App (of type core.App).
+	// We use a pocketbase.PocketBase instance as core.App and set its Meta.AppURL
+	// directly for isolated testing of MakeLink.
+	app := pocketbase.New()
+	h := NewHub(app)
+
+	tests := []struct {
+		name     string
+		appURL   string
+		parts    []string
+		expected string
+	}{
+		{
+			name:     "no parts, no trailing slash in AppURL",
+			appURL:   "http://localhost:8090",
+			parts:    []string{},
+			expected: "http://localhost:8090",
+		},
+		{
+			name:     "no parts, with trailing slash in AppURL",
+			appURL:   "http://localhost:8090/",
+			parts:    []string{},
+			expected: "http://localhost:8090", // TrimSuffix should handle the trailing slash
+		},
+		{
+			name:     "one part",
+			appURL:   "http://example.com",
+			parts:    []string{"one"},
+			expected: "http://example.com/one",
+		},
+		{
+			name:     "multiple parts",
+			appURL:   "http://example.com",
+			parts:    []string{"alpha", "beta", "gamma"},
+			expected: "http://example.com/alpha/beta/gamma",
+		},
+		{
+			name:     "parts with spaces needing escaping",
+			appURL:   "http://example.com",
+			parts:    []string{"path with spaces", "another part"},
+			expected: "http://example.com/path%20with%20spaces/another%20part",
+		},
+		{
+			name:     "parts with slashes needing escaping",
+			appURL:   "http://example.com",
+			parts:    []string{"a/b", "c"},
+			expected: "http://example.com/a%2Fb/c", // url.PathEscape escapes '/'
+		},
+		{
+			name:     "AppURL with subpath, no trailing slash",
+			appURL:   "http://localhost/sub",
+			parts:    []string{"resource"},
+			expected: "http://localhost/sub/resource",
+		},
+		{
+			name:     "AppURL with subpath, with trailing slash",
+			appURL:   "http://localhost/sub/",
+			parts:    []string{"item"},
+			expected: "http://localhost/sub/item",
+		},
+		{
+			name:     "empty parts in the middle",
+			appURL:   "http://localhost",
+			parts:    []string{"first", "", "third"},
+			expected: "http://localhost/first/third",
+		},
+		{
+			name:     "leading and trailing empty parts",
+			appURL:   "http://localhost",
+			parts:    []string{"", "path", ""},
+			expected: "http://localhost/path",
+		},
+		{
+			name:     "parts with various special characters",
+			appURL:   "https://test.dev/",
+			parts:    []string{"p@th?", "key=value&"},
+			expected: "https://test.dev/p@th%3F/key=value&",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Store original and defer restoration if app instance is reused across test functions (good practice)
+			originalAppURL := app.Settings().Meta.AppURL
+			app.Settings().Meta.AppURL = tt.appURL
+			defer func() { app.Settings().Meta.AppURL = originalAppURL }()
+
+			got := h.MakeLink(tt.parts...)
+			assert.Equal(t, tt.expected, got, "MakeLink generated URL does not match expected")
+		})
+	}
+}