How to populate error prop in functions.invoke response?

[timdiacon]

When calling an edge function via supabaseClient.functions.invoke the response can be destructured to { data, error } but I can't find any documentation on how to populate the error prop from the edge function? I'm sending back a Response object as per the documentation, whatever is placed in the body of the response populates the data prop on the front end. Is there a way of populating the error prop instead somehow?

return new Response(JSON.stringify(error), { status: 500 })

[sdaoud]

Supabase functions use Deno's Response interface. We can send back data to match { data, error } by doing something like this:

const { data, error } = await something()

if (error) {
  return new Response(JSON.stringify({ error: error }), { status: 500 })
} else {
  return new Response(JSON.stringify({ data: data }), { status: 200 })
}

Or even better, if we know something() always returns { data, error } we can do:

const response = await something()
return new Response(JSON.stringify(response), { status: response.error ? 500 : 200 })

[sdaoud]

When you're calling return new Response(JSON.stringify(error), { status: 500 }) it must be populating the data prop because of the contents of error. If you do console.log(error) before that, I imagine you'll see something like this:

{
  data: {
    message: "something went wrong",
    status: 422
  }
}

So you'd need to do this:

if (error) {
  return new Response(JSON.stringify({ error: error.data.message }), { status: error.data.status })
}

[laktek]

Yes, that does the trick. Check Supabase's Edge Functions examples for similar implementations:

[t-lock]

@laktek Apologies for tagging you on an old thread, but that really doesn't do the trick. When using the example code from the supabase edge functions example, supabaseClient.functions.invoke() will always use its own internal error messaging "Edge Function returned a non-2xx status code"...

If you want to pass your own message, it does not seem possible to do so on a Deno response of status of anything other than 200. We have to just give a successful response and attach the error data there.

In Edge function:

  try {
    throw new Error("Custom Error Message");
  } catch (error) {
    return new Response(
      JSON.stringify({ error: error.message }),
      {
        headers: { ...corsHeaders, "Content-Type": "application/json" },
        status: 403,
      },
    );
  }

In browser client:

      const { data, error} = await supabase.functions.invoke("some-function");
      console.log(data, error);

The error variable logged to console will be "Function returned a non-2xx status code", even though our network tab will show the 403 response with our custom error message, and data will be null.

However, if we change our status to 200, we will be able to find our error message in data: {error: "Custom Error Message"}, while error will be null.

So the question remains: How can we surface the error message when using a Deno response with a proper error status (non 2xx)?

[Mohammed-Yasin-Mulla]

I do have the same question @t-lock .