simplified test case and remove error

src/batch.luau

@@ -16,8 +16,8 @@ local function batch(setter: () -> ())
     local ok, err: string? = pcall(setter)
 
     if not already_batching then
-        flush()
         flags.batch = false
+        flush()
     end
 
     if not ok then throw(`error occured while batching updates: {err}`) end

src/graph.luau

@@ -184,13 +184,10 @@ local function queue_children_for_update<T>(node: SourceNode<T>)
     update_queue.n = i
 end
 
-local _flushing = false
 local function flush_update_queue()
     local n0 = update_queue.n
 
     return function()
-        assert(not _flushing, "recursive queue flush occured") -- todo
-        _flushing = true
 
         local i = n0 + 1
         while i <= update_queue.n do
@@ -207,7 +204,6 @@ local function flush_update_queue()
         
         update_queue.n = n0
 
-        _flushing = false
     end
 end
 

test/tests.luau

@@ -1924,28 +1924,17 @@ TEST("batch()", wrap_root(function()
     do CASE "recursive queue flush"
 
         local a0 = source(0)
-        local a1 = source(1)
-        local a2 = source(0)
+        local a1 = source(0)
         local updates = 0
 
-        derive(function()
-            a0(a1() + 1)
+        derive(function() -- depends on a1
+            a0(a1())
         end)
 
-        derive(function()
+        derive(function() -- batch updates a2
             updates += 1
             a0()
             
-            batch(function()
-                a2(a0())
-            end)
-
-            return 1
-        end)
-
-        derive(function()
-            a2()
-            
             batch(function()
 
             end)
@@ -1953,7 +1942,7 @@ TEST("batch()", wrap_root(function()
             return 1
         end)
 
-        a1(2)
+        a1(1)
         CHECK(updates == 2)
     end
 end))