Unable to use ArkType with Expo

[eduardo-gualberto]

Report a bug

🔎 Search Terms

@babel/plugin-transform-class-static-block
expo

🧩 Context

• ArkType version: 2.0.0-dev.25
• TypeScript version (5.1+): 5.5.2
• Other context you think may be relevant (JS flavor, OS, etc.): MacOS, Apple Silicon, React Native, Expo

🧑‍💻 Repro

I'll leave a repository containing a minimal reproduction code: https://github.com/eduardo-gualberto/arktype-repro-01

import { StatusBar } from "expo-status-bar";
import { StyleSheet, Text, View } from "react-native";
import { type } from "arktype";

export default function App() {
  const myType = type({
    test: "string",
    test2: "number>5",
  });
  return (
    <View style={styles.container}>
      <Text>Open up App.tsx to start working on your app!</Text>
      <StatusBar style="auto" />
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: "#fff",
    alignItems: "center",
    justifyContent: "center",
  },
});

I noticed I could not make arktype work with a create-expo-app (typescript templated) project.

It first complains about a missing babel plugin called plugin-transform-class-static-block. Such as bellow.

Then, after installing the plugin and adding it to babel.config, the error changes to

[ssalbdivad]

Thanks for logging this! It looks like a bug with the way Expo/babel are parsing the TypeScript output for decorators.

I have my tsconfig target set to ES2022, so as long as the parser supports at least that, it should work out of the box.

I'm not sure about intersection.equals being undefined in hermes, but given that it works in every other runtime I've tested, it also seems worth opening an issue with the maintainers of that project to see if they have an idea what's going on.

I'm happy to try and accommodate this environment if there are specific, targeted changes I can make to do so.

[eduardo-gualberto]

Thank you for replying so quickly!

It seems there are quite a few problems just like that with the hermes interpreter, not my lucky day.

The crazy thing is that using version 2.0.0-dev.0 of ArkType the problem seems to go away.

[ssalbdivad]

I can't say for sure what was in the newer releases that wasn't in that one, but I can say I can't maintain a limited feature set based on what Hermes supports going forward.

If there's a specific problem I can easily address please do let me know as I'd love to help. I'll close this issue for now.