Move equal helpers into pkg/cookiebanner as unexported functions

Signed-off-by: Émile Ré <emile@getprobo.com>

pkg/cookiebanner/equal.go

@@ -0,0 +1,45 @@
+// Copyright (c) 2026 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package cookiebanner
+
+import (
+	"encoding/json"
+	"fmt"
+	"reflect"
+)
+
+// ptrEqual reports whether two nullable values are equal: both nil are equal,
+// one nil is not equal to a non-nil, otherwise the pointed-to values are
+// compared with ==.
+func ptrEqual[T comparable](a, b *T) bool {
+	if a == nil || b == nil {
+		return a == b
+	}
+	return *a == *b
+}
+
+// jsonEqual reports whether two JSON blobs are semantically identical after
+// normalising whitespace and key ordering. Array element order is preserved
+// as significant.
+func jsonEqual(a, b json.RawMessage) (bool, error) {
+	var av, bv any
+	if err := json.Unmarshal(a, &av); err != nil {
+		return false, fmt.Errorf("cannot unmarshal first json blob: %w", err)
+	}
+	if err := json.Unmarshal(b, &bv); err != nil {
+		return false, fmt.Errorf("cannot unmarshal second json blob: %w", err)
+	}
+	return reflect.DeepEqual(av, bv), nil
+}