From ad226b6fb1bdfe5f30c3a9e0cd50cc91c84a49f7 Mon Sep 17 00:00:00 2001
From: Pierre Tachoire <pierre@lightpanda.io>
Date: Thu, 26 Feb 2026 15:30:32 +0100
Subject: [PATCH 1/3] implement storage size limit per origin

---
 src/browser/webapi/storage/storage.zig | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/browser/webapi/storage/storage.zig b/src/browser/webapi/storage/storage.zig
index 64dfae23..752ef1d3 100644
--- a/src/browser/webapi/storage/storage.zig
+++ b/src/browser/webapi/storage/storage.zig
@@ -60,6 +60,9 @@ pub const Bucket = struct { local: Lookup = .{}, session: Lookup = .{} };
 
 pub const Lookup = struct {
     _data: std.StringHashMapUnmanaged([]const u8) = .empty,
+    _size: usize = 0,
+
+    const max_size = 5 * 1024 * 1024;
 
     pub fn getItem(self: *const Lookup, key_: ?[]const u8) ?[]const u8 {
         const k = key_ orelse return null;
@@ -69,6 +72,11 @@ pub const Lookup = struct {
     pub fn setItem(self: *Lookup, key_: ?[]const u8, value: []const u8, page: *Page) !void {
         const k = key_ orelse return;
 
+        if (self._size + value.len > max_size) {
+            return error.QuotaExceeded;
+        }
+        defer self._size += value.len;
+
         const key_owned = try page.dupeString(k);
         const value_owned = try page.dupeString(value);
 
@@ -112,7 +120,7 @@ pub const Lookup = struct {
 
         pub const length = bridge.accessor(Lookup.getLength, null, .{});
         pub const getItem = bridge.function(Lookup.getItem, .{});
-        pub const setItem = bridge.function(Lookup.setItem, .{});
+        pub const setItem = bridge.function(Lookup.setItem, .{ .dom_exception = true });
         pub const removeItem = bridge.function(Lookup.removeItem, .{});
         pub const clear = bridge.function(Lookup.clear, .{});
         pub const key = bridge.function(Lookup.key, .{});

From c61eda0d241b73ae7fa89d9f8f8fb1b5854bec70 Mon Sep 17 00:00:00 2001
From: Pierre Tachoire <pierre@lightpanda.io>
Date: Thu, 26 Feb 2026 15:51:01 +0100
Subject: [PATCH 2/3] crypto: use dom exception to return QuotaExceededError

---
 src/browser/webapi/Crypto.zig | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/browser/webapi/Crypto.zig b/src/browser/webapi/Crypto.zig
index 89324695..a79fbc40 100644
--- a/src/browser/webapi/Crypto.zig
+++ b/src/browser/webapi/Crypto.zig
@@ -32,7 +32,7 @@ pub fn getRandomValues(_: *const Crypto, js_obj: js.Object) !js.Object {
     var into = try js_obj.toZig(RandomValues);
     const buf = into.asBuffer();
     if (buf.len > 65_536) {
-        return error.QuotaExceededError;
+        return error.QuotaExceeded;
     }
     std.crypto.random.bytes(buf);
     return js_obj;
@@ -82,7 +82,7 @@ pub const JsApi = struct {
         pub const empty_with_no_proto = true;
     };
 
-    pub const getRandomValues = bridge.function(Crypto.getRandomValues, .{});
+    pub const getRandomValues = bridge.function(Crypto.getRandomValues, .{ .dom_exception = true });
     pub const randomUUID = bridge.function(Crypto.randomUUID, .{});
     pub const subtle = bridge.accessor(Crypto.getSubtle, null, .{});
 };

From ef6a7a6904d865e3b86232535260731641a005fa Mon Sep 17 00:00:00 2001
From: Pierre Tachoire <pierre@lightpanda.io>
Date: Fri, 27 Feb 2026 08:51:22 +0100
Subject: [PATCH 3/3] storage: maintain Lookup size correctly

---
 src/browser/tests/storage.html         | 9 +++++++++
 src/browser/webapi/storage/storage.zig | 6 +++++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/browser/tests/storage.html b/src/browser/tests/storage.html
index 7633293b..cb41bb3d 100644
--- a/src/browser/tests/storage.html
+++ b/src/browser/tests/storage.html
@@ -88,3 +88,12 @@
   localStorage.clear();
   testing.expectEqual(0, localStorage.length)
 </script>
+
+<script id="localstorage_limits">
+  localStorage.clear();
+  for (i = 0; i < 5; i++) {
+    const v =  "v".repeat(1024 * 1024);
+    localStorage.setItem(v, v);
+  }
+  testing.expectError("QuotaExceededError", () => localStorage.setItem("last", "v"));
+</script>
diff --git a/src/browser/webapi/storage/storage.zig b/src/browser/webapi/storage/storage.zig
index 752ef1d3..1787dfee 100644
--- a/src/browser/webapi/storage/storage.zig
+++ b/src/browser/webapi/storage/storage.zig
@@ -86,11 +86,15 @@ pub const Lookup = struct {
 
     pub fn removeItem(self: *Lookup, key_: ?[]const u8) void {
         const k = key_ orelse return;
-        _ = self._data.remove(k);
+        if (self._data.get(k)) |value| {
+            self._size -= value.len;
+            _ = self._data.remove(k);
+        }
     }
 
     pub fn clear(self: *Lookup) void {
         self._data.clearRetainingCapacity();
+        self._size = 0;
     }
 
     pub fn key(self: *const Lookup, index: u32) ?[]const u8 {