ExpressReceiver's RespondFn implementation doesn't accept a string

[seratch]

Description

The default implementation of respond by ExpressReceiver doesn't accept a string argument. It has been working only with RespondArguments since version 1.0.0.

• The type definition of RespondFn: https://github.com/slackapi/bolt/blob/%40slack/bolt%401.5.0/src/types/utilities.ts#L21-L23
• ExpressReceivers respond implementation: https://github.com/slackapi/bolt/blob/%40slack/bolt%401.5.0/src/ExpressReceiver.ts#L103-L108

Thank you @marks for reporting this issue. Refer to the thread in Slack Community Workspace.

--- (His original report there) ---

https://slack.dev/bolt docs say I can use:

respond(`You selected <@${action.selected_user}>`);

but when I try to do something like this, I get a 500 / invalid_payload back from the Slack API.
It appears you need to do:

respond({text: `You selected <@${action.selected_user}>`});

Is this a bug/regression? It seems the Slack webhook/response URLs do not take plain text

What type of issue is this? (place an x in one of the [ ])

• bug
• enhancement (feature request)
• question
• documentation related
• testing related
• discussion

Requirements (place an x in each of the [ ])

• I've read and understood the Contributing guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.
• I've searched for any related issues and avoided creating a duplicate issue.

---

Bug Report

Reproducible in:

package version: any
node version: any
OS version(s): any

Steps to reproduce:

1. Have respond("Hi there!"); in a Bolt app

Expected result:

The API call successfully completes.

Actual result:

The Bolt app gets a 500 / invalid_payload back from the Slack API.

Attachments: