SolidJS•3mo ago

Proxy error

Hi, I'm a beginner in Solid and I wrote a little app to learn it. https://github.com/gbagan/nim-machine/blob/test/src/App.tsx In this app, I have created a store state which contains an attribute config (line 42) Then, I wrote a function changeConfig which modifies the store (line 132)

const changeConfig = (fn: (c: Config) => Config) => {
    setState(produce(state => {
      state.config = fn(state.config);
      state.victories = 0;
      state.losses = 0;
      state.isRunning = false;
      const graph = getGraph(state);
      state.machine = graphToMachine(graph, state.config.ballsPerColor);
    }))
  }

const changeConfig = (fn: (c: Config) => Config) => {
    setState(produce(state => {
      state.config = fn(state.config);
      state.victories = 0;
      state.losses = 0;
      state.isRunning = false;
      const graph = getGraph(state);
      state.machine = graphToMachine(graph, state.config.ballsPerColor);
    }))
  }

When, this function is called, I obtain the following message error:

Uncaught TypeError: proxy must report the same value for the non-writable, non-configurable property 'Symbol("solid-proxy")'

on the line state.config = fn(state.config). Initially I wrote this function differently (without using produce) and it worked fine. I'd like to understand this error and how to prevent it.

3 Replies

GuillaumeOP•3mo ago

I have fixed the problem by using a function fn that mutates the Config object instead of returning a new one (and modifying the calls of changeConfig accordingly).

const changeConfig = (fn: (c: Config) => void) => {
  setState(produce(state => {
    fn(state.config);
    ...

const changeConfig = (fn: (c: Config) => void) => {
  setState(produce(state => {
    fn(state.config);
    ...

but I still don't understand the issue.

Maciek50322•3mo ago

I see that you use changeConfig different ways

changeConfig(c => setGraphType(c, e.currentTarget.value))
...
changeConfig(produce(conf => {
  (conf.graphType as KingType).width = Number(e.currentTarget.value);
}))

changeConfig(c => setGraphType(c, e.currentTarget.value))
...
changeConfig(produce(conf => {
  (conf.graphType as KingType).width = Number(e.currentTarget.value);
}))

the changeConfig already uses produce, I think using produce second time inside is the thing that breaks? If you want to pass control to the function caller, you can do something like that:

const changeConfig: SetStoreFunction<Config> = (...configNextSetterArgs: any[]) => {
  batch(() => {
    (setState as any)("config", ...configNextSetterArgs);
    setState(produce(state => {
      state.victories = 0;
      state.losses = 0;
      state.isRunning = false;
      const graph = getGraph(state);
      state.machine = graphToMachine(graph, state.config.ballsPerColor);
    }))
  })
}

const changeConfig: SetStoreFunction<Config> = (...configNextSetterArgs: any[]) => {
  batch(() => {
    (setState as any)("config", ...configNextSetterArgs);
    setState(produce(state => {
      state.victories = 0;
      state.losses = 0;
      state.isRunning = false;
      const graph = getGraph(state);
      state.machine = graphToMachine(graph, state.config.ballsPerColor);
    }))
  })
}

I added ...configNextSetterArgs: any[], (setState as any), because typescript can't match the types for SetStoreFunction, probably because it's quite complex

GuillaumeOP•3mo ago

Thank you, that is exactly what I wanted

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Proxy error