[intellix]

What is it?

• Bug

Description

Spreading an object into a component drops every key whose value is null:

const Child = component$((props: { a: number; s: { p: number } | null }) => (
  <span>{JSON.stringify(Object.keys(props))}</span>
));

const data = { a: 1, s: null };
<Child {...data} />          // ["a"]: `s` is gone
<Child a={1} s={null} />      // ["a", "s"]

The key is missing only when it's spread. Explicit props keep null, and an undefined value survives the spread. A component typed s: T | null therefore gets undefined, and props.s !== null is true. We hit this in a list built by spreading GraphQL results into a card component. GraphQL uses null for absent values, so every card read as "sponsored". On v1 the null arrives.

Cause

When there's a spread, the optimizer emits _jsxSplit. At the end it removes every null var prop:

} else if (varProps[k] === null) {
  ...
  // Clean up null markers (from event conversions)
  delete varProps[k];
}

Those markers come from event-prop conversion, which _jsxSplit only does for native elements (typeof type === 'string'). On a component the same check deletes real props.

Fix

Only run the null cleanup for native elements, the same condition _jsxSplit already uses for its other element-only transforms. Elements are unchanged: a spread null attribute is still dropped, which is what null means for an attribute.

Tests

A new test in component.spec.tsx spreads { a: 1, s: null } into a component and checks s arrives as null. It runs under both ssrRenderToDom and domRender, fails on main (expected 'false:false' to be 'true:true'), and passes with the fix. The full packages/qwik/src/core suite passes (2394 tests).

Checklist

• My code follows the developer guidelines of this project
• I performed a self-review of my own code
• I added a changeset with pnpm change
• I added new tests to cover the fix / functionality

[changeset-bot]

🦋 Changeset detected

Latest commit: b1b6348

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 8 packages

Name	Type
@qwik.dev/core	Patch
@qwik.dev/devtools	Patch
eslint-plugin-qwik	Patch
@qwik.dev/mcp	Patch
@qwik.dev/react	Patch
@qwik.dev/router	Patch
@qwik.dev/utils	Patch
create-qwik	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[pkg-pr-new]

Open in StackBlitz

@qwik.dev/core

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/core@9193

@qwik.dev/router

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/router@9193

@qwik.dev/utils

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/utils@9193

eslint-plugin-qwik

npm i https://pkg.pr.new/QwikDev/qwik/eslint-plugin-qwik@9193

create-qwik

npm i https://pkg.pr.new/QwikDev/qwik/create-qwik@9193

@qwik.dev/optimizer

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/optimizer@9193

@qwik.dev/devtools

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/devtools@9193

@qwik.dev/mcp

npm i https://pkg.pr.new/QwikDev/qwik/@qwik.dev/mcp@9193

commit: b1b6348

[Varixo]

Lgtm