From 064d81bd01cc765cc11faf287876065032279daa Mon Sep 17 00:00:00 2001
From: David Maskasky <dmaskasky@gmail.com>
Date: Sat, 16 Nov 2024 18:47:31 -0800
Subject: [PATCH] add tests: atoms accessed with write get should have their
 dependencies updated

---
 tests/vanilla/dependency.test.tsx | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/tests/vanilla/dependency.test.tsx b/tests/vanilla/dependency.test.tsx
index 59ae209ae8..619218429f 100644
--- a/tests/vanilla/dependency.test.tsx
+++ b/tests/vanilla/dependency.test.tsx
@@ -334,3 +334,29 @@ it('handles complex dependency chains', async () => {
   resolve()
   expect(await promise2).toBe(10)
 })
+
+it('updates dependencies for atoms accessed with write get', () => {
+  const store = createStore()
+  const a = atom(0)
+  const bRead = vi.fn((get) => get(a))
+  const b = atom(bRead)
+  const c = atom(null, (get) => get(b))
+  store.sub(a, () => {})
+  store.set(c)
+  bRead.mockClear()
+  store.set(a, 1)
+  // note: this behavior is required for the next test to work
+  expect(bRead).toHaveBeenCalledOnce()
+  expect(store.get(a)).toBe(1)
+})
+
+it('can read sync derived atom in write without initializing', () => {
+  const store = createStore()
+  const a = atom(0)
+  const b = atom((get) => get(a) + 1)
+  const c = atom(null, (get, set) => set(a, get(b)))
+  store.set(c)
+  expect(store.get(a)).toBe(1)
+  store.set(c)
+  expect(store.get(a)).toBe(2) // note: this is why write get needs to update deps
+})