className swap after a frozen-time theme flip applies an empty style — Text paints default ink (Pro 1.6.0)

[invivek26]

What happened?

A deterministic follow-up to #649, but in the native className lane (so #650 does not cover it): after a theme flip that lands while a screen is frozen (react-freeze via native-stack/tabs), the first className swap on a node of that screen — a plain cn/tv conditional flipping between two class strings — paints with no resolved color at all. On Text that means React Native's default black ink.

Pixel evidence from the repro (iOS 26 simulator, iPhone 17 Pro): a segmented pill whose selected variant is bg-brand text-on-brand, where --color-on-brand: #ffffff in the base @theme block and both theme variants. After the frozen-time dark→light flip, tapping the never-yet-selected pill paints:

• pill background: rgb(0,57,228) — correct brand blue (this one is resolved with useResolveClassNames into a style object for a non-uniwind native view, i.e. the pure JS lane — always correct)
• label glyphs: rgb(0,0,1) — not dark's value, not light's value, and the token is identical in every theme block. This is RN's default text color: the style landed empty, not wrong-theme

Observed behavior matrix from the same session (all in one commit sequence, minutes after the flip, so no hydration race):

1. Pill Y swaps to the selected string (first time this node carries it) → label black
2. Pill X swaps to the unselected string in the same commit → fully correct (#2d2d2d, light foreground)
3. Next swap: X back to selected → correct white; Y to unselected stays black (should be #2d2d2d)
4. One more swap: Y back to selected → heals, correct white from then on

So the broken node stays broken through one more className change and recovers on the second — an erratic warm-up rather than a stable wrong value. Flips performed while the screen is visible don't reproduce; strings that were rendered at least once under the boot theme survive flips fine (the flip lane itself re-commits mounted classNames correctly).

Where it smells from reading the source, offered with appropriate humility:

• HybridShadowRegistry::updateShadowTree seeds family->nativeProps_DEPRECATED for suspended/frozen families, and that stash is cleared only in UniwindStore::linkShadowNodeWithUniwindStyle — which runs from the component's ref callback, i.e. after the commit that carried the new className. The clearing comment there already mentions "timing conflicts". A stale stash merging over the swap commit (or a merge payload the RawProps parser rejects, nulling color) would produce exactly a default-ink paint.
• For RuntimeChangeSource.User flips, updateTree is deferred behind requestIdleCallback (components/native/utils/listener.ts). We also run the updateCSSVariables(theme, {}) re-commit workaround from [Pro 1.1.0 / iOS] bg-* views stuck on previous theme after OS appearance flip + react-navigation native-stack push/pop #518 shortly after each flip, and setPendingCommit replaces any pending commit — if the idle-deferred update and the recommit interleave, half-applied state seems reachable.

Steps to Reproduce

1. Two registered themes, with at least one color token whose value is identical in both (e.g. --color-on-brand: #ffffff in base + both variants).
2. A tab/stack screen (frozen on blur) renders segmented pills via a tv/cn conditional: selected → bg-brand text-on-brand, unselected → bg-glass-fill text-foreground. Pill X starts selected, pill Y unselected.
3. Cold-start the app in dark.
4. Navigate away so the screen freezes.
5. Uniwind.setTheme('light').
6. Navigate back — the whole screen is correctly re-themed (the flip lane works).
7. Tap pill Y. Its label renders with RN default black ink (no color); its background and every other node in the commit are correct.
8. Tap X, then Y again — Y's label stays black through the first swap and heals on the second.

Sketch of the component shape (illustrative):

const pill = tv({
  slots: { label: "text-center", tab: "rounded-full px-4 py-2" },
  variants: {
    selected: {
      true: { label: "text-on-brand", tab: "bg-brand" },
      false: { label: "text-foreground", tab: "bg-glass-fill" },
    },
  },
})

const Pills = ({ value, onChange }) => (
  <View className="flex-row gap-2">
    {OPTIONS.map((option) => (
      <Pressable key={option} onPress={() => onChange(option)} className={pill().tab({ selected: option === value })}>
        <Text className={pill().label({ selected: option === value })}>{option}</Text>
      </Pressable>
    ))}
  </View>
)

Happy to run instrumented builds against our reproduction if that helps — it triggers on the first try with the steps above.

Snack or Repository Link (Optional)

No response

Uniwind version

uniwind-pro 1.6.0

React Native Version

0.85.3

Platforms

iOS

Expo

Yes

Additional information 〰

• I've searched for similar issues in this repository and found none
• I am a Uniwind Pro user

[github-actions]

This issue has been automatically closed because it lacks a repository with a minimal reproduction that we can use to verify the reported bug.

[invivek26]

@Brentlok could you reopen this one? The empty repro-repo field is deliberate, not an omission: the bug is in the Pro native lane, and a public repository can't vendor the Pro package without violating the license. That constraint applies to every Pro-lane report, so the auto-close effectively can't be satisfied publicly.

What I can offer instead, whichever you prefer:

• a private minimal repro repo (fresh Expo app, two themes, freezeOnBlur screen, the segmented pills from the sketch) that declares "uniwind": "1.6.0" as a plain registry dependency — no Pro code committed, installable with your own registry access; I'll add whoever you name as a collaborator
• running instrumented builds on our reproduction — the steps in the report trigger it on the first try, so a debug branch or extra logging gets you a verified trace quickly

Same shape as #649, which you triaged and fixed in #650 without a repro repo.

[invivek26]

Re-filed with the runnable repro the automation asked for: #655. Key finding while building it: React Compiler is a required ingredient — five progressively-closer variants without it don't reproduce; with it, deterministic.

[Brentlok]

@Brentlok could you reopen this one?

Issue wasn't reported using template directly in github so labels were not added, and the issue validation action couldn't knew that it's a pro issue.

For the future, please just wait for us to reopen your issue if something like that happens.

[jpudysz]

Reproduced!