fix(types): add undefined initial value to Atom definition

[rtritto]

Related Bug Reports or Discussions

Discussion #2667

Fixes #2666

Check List

• [x] pnpm run prettier for formatting code and docs

[vercel[bot]]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
jotai	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jul 23, 2024 9:09am

[codesandbox-ci[bot]]

This pull request is automatically built and testable in CodeSandbox.

To see build info of the built libraries, click here or the icon next to each commit SHA.

[rtritto]

Does it also need a change like this?

// write-only derived atom
export function atom<Value, Args extends unknown[], Result>(
-  initialValue: Value,
+  initialValue?: Value,
  write: Write<Args, Result>,
-): WritableAtom<Value, Args, Result> & WithInitialValue<Value>
+): WritableAtom<Value | undefined, Args, Result> & WithInitialValue<Value | undefined>

[dai-shi]

No, I think it should be explicit, and also TS doesn't allow it.

[rtritto]

Done

[github-actions[bot]]

Preview in LiveCodes

Latest commit: bd1348ff9002db031103c3b40ee6bf8a4d136330
Last updated: Jul 23, 2024 9:08am (UTC)

Playground	Link
React demo	https://livecodes.io?x=id/2YMSGQ3UN

---

See documentations for usage instructions.

[rtritto]

Done

[dai-shi]

@rtritto A friendly reminder

• https://github.com/pmndrs/jotai/pull/2668#discussion_r1685413543
• Please check CI results

[rtritto]

@dai-shi I need some help

[dai-shi]

Sure, but for which one? Let's first focus on the first one.

[rtritto]

It's related to vanilla/types.test

[dai-shi]

Please add this and if you have more ideas, please add them.

diff --git a/tests/vanilla/types.test.tsx b/tests/vanilla/types.test.tsx
index e0744b8..3c89725 100644
--- a/tests/vanilla/types.test.tsx
+++ b/tests/vanilla/types.test.tsx
@@ -1,4 +1,5 @@
 import { expectType } from 'ts-expect'
+import type { TypeOf } from 'ts-expect'
 import { it } from 'vitest'
 import { atom } from 'jotai/vanilla'
 import type {
@@ -15,6 +16,15 @@ it('atom() should return the correct types', () => {
     // primitive atom
     const primitiveAtom = atom(0)
     expectType<PrimitiveAtom<number>>(primitiveAtom)
+    expectType<TypeOf<PrimitiveAtom<number>, typeof primitiveAtom>>(true)
+    expectType<TypeOf<PrimitiveAtom<number | undefined>, typeof primitiveAtom>>(
+      false,
+    )
+
+    // primitive atom without initial value
+    const primitiveWithoutInitialAtom = atom<number | undefined>()
+    expectType<PrimitiveAtom<number | undefined>>(primitiveWithoutInitialAtom)
+    expectType<PrimitiveAtom<undefined>>(atom())

     // read-only derived atom
     const readonlyDerivedAtom = atom((get) => get(primitiveAtom) * 2)

[rtritto]

Done (no other ideas)

[dai-shi]

Size Change: 0 B

Total Size: 87 kB

ℹ️ View Unchanged

| Filename | Size | | :--- | :---: | | `./dist/babel/plugin-debug-label.js` | 932 B | | `./dist/babel/plugin-react-refresh.js` | 1.14 kB | | `./dist/babel/preset.js` | 1.41 kB | | `./dist/esm/babel/plugin-debug-label.mjs` | 1 kB | | `./dist/esm/babel/plugin-react-refresh.mjs` | 1.19 kB | | `./dist/esm/babel/preset.mjs` | 1.49 kB | | `./dist/esm/index.mjs` | 62 B | | `./dist/esm/react.mjs` | 1.02 kB | | `./dist/esm/react/utils.mjs` | 746 B | | `./dist/esm/utils.mjs` | 67 B | | `./dist/esm/vanilla.mjs` | 3.83 kB | | `./dist/esm/vanilla/utils.mjs` | 4.95 kB | | `./dist/index.js` | 242 B | | `./dist/react.js` | 1.06 kB | | `./dist/react/utils.js` | 1.39 kB | | `./dist/system/babel/plugin-debug-label.development.js` | 1.1 kB | | `./dist/system/babel/plugin-debug-label.production.js` | 775 B | | `./dist/system/babel/plugin-react-refresh.development.js` | 1.29 kB | | `./dist/system/babel/plugin-react-refresh.production.js` | 928 B | | `./dist/system/babel/preset.development.js` | 1.59 kB | | `./dist/system/babel/preset.production.js` | 1.14 kB | | `./dist/system/index.development.js` | 252 B | | `./dist/system/index.production.js` | 183 B | | `./dist/system/react.development.js` | 1.17 kB | | `./dist/system/react.production.js` | 715 B | | `./dist/system/react/utils.development.js` | 860 B | | `./dist/system/react/utils.production.js` | 462 B | | `./dist/system/utils.development.js` | 257 B | | `./dist/system/utils.production.js` | 187 B | | `./dist/system/vanilla.development.js` | 3.92 kB | | `./dist/system/vanilla.production.js` | 2.06 kB | | `./dist/system/vanilla/utils.development.js` | 5.16 kB | | `./dist/system/vanilla/utils.production.js` | 3.09 kB | | `./dist/umd/babel/plugin-debug-label.development.js` | 1.08 kB | | `./dist/umd/babel/plugin-debug-label.production.js` | 852 B | | `./dist/umd/babel/plugin-react-refresh.development.js` | 1.27 kB | | `./dist/umd/babel/plugin-react-refresh.production.js` | 1 kB | | `./dist/umd/babel/preset.development.js` | 1.54 kB | | `./dist/umd/babel/preset.production.js` | 1.22 kB | | `./dist/umd/index.development.js` | 383 B | | `./dist/umd/index.production.js` | 328 B | | `./dist/umd/react.development.js` | 1.18 kB | | `./dist/umd/react.production.js` | 786 B | | `./dist/umd/react/utils.development.js` | 1.53 kB | | `./dist/umd/react/utils.production.js` | 1.01 kB | | `./dist/umd/utils.development.js` | 399 B | | `./dist/umd/utils.production.js` | 342 B | | `./dist/umd/vanilla.development.js` | 4.91 kB | | `./dist/umd/vanilla.production.js` | 2.69 kB | | `./dist/umd/vanilla/utils.development.js` | 6.07 kB | | `./dist/umd/vanilla/utils.production.js` | 3.72 kB | | `./dist/utils.js` | 247 B | | `./dist/vanilla.js` | 4.81 kB | | `./dist/vanilla/utils.js` | 5.94 kB |

_{compressed-size-action}