Add sibling()

src/init.luau

@@ -16,6 +16,7 @@ local derive = require(script.derive)
 local cleanup = require(script.cleanup)
 local untrack = require(script.untrack)
 local parent = require(script._parent)
+local sibling = require(script.sibling)
 local read = require(script.read)
 local batch = require(script.batch)
 local context = require(script.context)
@@ -70,6 +71,7 @@ local vide = {
     cleanup = cleanup,
     untrack = untrack,
     parent = parent,
+    sibling = sibling,
     read = read,
     batch = batch,
     context = context,

src/sibling.luau

@@ -0,0 +1,32 @@
+if not game then script = require "test/relative-string" end
+
+local graph = require(script.Parent.graph)
+type Node<T> = graph.Node<T>
+
+export type Source<T> = (() -> T) & ((value: T) -> T)
+
+local function sibling<T>(fn: () -> T): (() -> (), T)
+    local node = graph.get_scope()
+    if not node then error("") end
+
+    local parent_node = node.owner
+    if not parent_node then error("") end
+
+    local sibling = graph.create_node(parent_node :: Node<unknown>, false, false)
+
+    graph.push_scope(sibling)
+
+    local ok, result = pcall(fn)
+
+    graph.pop_scope()
+
+    if not ok then error(result, 0) end
+
+    local function destroy()
+        graph.destroy(sibling)
+    end
+
+    return destroy, result
+end
+
+return sibling :: (<T>(fn: () -> T) -> (() -> (), T)) & ((fn: () -> ()) -> () -> ())

test/tests.luau

@@ -1825,6 +1825,43 @@ TEST("parent()", function()
     end
 end)
 
+TEST("sibling()", function()
+    local root = vide.root
+    local source = vide.source
+    local effect = vide.effect
+    local sibling = vide.sibling
+    local context = vide.context
+    local cleanup = vide.cleanup
+    local untrack = vide.untrack
+
+    local ctx = context(0)
+    local src = source(0)
+
+    local cleanup_count = 0
+    local ran = false
+
+    local destroy = root(function()
+        ctx(1, function()
+            effect(function()
+                src()
+                if not ran then ran = true
+                    sibling(function()
+                        effect(function()
+                            cleanup(function() cleanup_count += 1 end)
+                            CHECK(ctx() == 1)
+                        end)
+                    end)
+                end
+            end)
+        end)
+    end)
+
+    src(1)
+    CHECK(cleanup_count == 0)
+    destroy()
+    CHECK(cleanup_count == 1)
+end)
+
 TEST("events", function()
     local create = vide.create