#Custom errors thrown from server actions are converted to generic Error

8 messages · Page 1 of 1 (latest)

torn temple
#

When I throw a custom error in my server action, the client sees it as a normal Error:

export class MyCustomError extends Error {
  constructor(message: string) {
    super(message);
    this.name = 'MyCustomError';
    // Object.setPrototypeOf(this, MyCustomError.prototype);
  }
}

'use server'

export async function someServerAction() {
    throw new MyCustomError('blah blah blah')
}

try {
    someServerAction()
} catch (err) {
    console.log(err instance of MyCustomError) // false
    console.log(err.name) // 'Error'
    console.log(err instance of Error) // true
}
thin finchBOT
#
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fiery heron
torn temple
#

Thank you so much! let me try it.

torn temple
#

Well, I was looking for a way to throw custom errors from my server actions so I can catch them with instanceof in client

#

If the only way is to return a normal response that includes the error message, then is this pattern good?:

try {
    const res = await callServerAction()
    if (res.error) {
      throw new Error(res.error.message)
    }
    // ... rest of function
} catch (err) {
    alert('unexpected error', err.message)
}
#

using try/catch for unexpected errors, and throw an error for expected errors, and show an alert or a toast or whatever for both of them

fiery heron