checkboxes in markdown_text when using web-api fails and returns slack_webapi_platform_error

[tylerkohn]

Using markdown_text fails when sending checkboxes. A slack_webapi_platform_error error is returned.

Note: This appears to be a Slack Web API server-side issue rather than an SDK issue.

Packages:

Select all that apply:

• @slack/web-api
• @slack/rtm-api
• @slack/webhooks
• @slack/oauth
• @slack/socket-mode
• @slack/types
• I don't know

Reproducible in:

The Slack SDK version

@slack/web-api 7.10.0

Node.js runtime version

v22.17.0

OS info

ProductName: macOS
ProductVersion: 14.5
BuildVersion: 23F79
Darwin Kernel Version 23.5.0: Wed May 1 20:13:18 PDT 2024; root:xnu-10063.121.3~5/RELEASE_ARM64_T6030

Steps to reproduce:

import { WebClient } from "@slack/web-api";
...
      const slackBotToken = "XXXXXXXXXXXXXX";
      const client = new WebClient(slackBotToken);

Works:

      const testText1 =
        "*bold* _italic_ `code` [Google](https://google.com)  \n\n\n # test";
      const result1 = await client.chat.postMessage({
        channel: targetChannel,
        markdown_text: testText1,
        token: slackBotToken,
      });

Results in an Error:

      const testText2 =
        "*bold* _italic_ `code` [Google](https://google.com) \n\n\n - [ ] option1 \n- [x] option2 \n\n\n # test";
      const result2 = await client.chat.postMessage({
        channel: targetChannel,
        markdown_text: testText2,
        token: slackBotToken,
      });

Some additional testing I think shows that this will not error:

- [] option1 \n- [X] option2

this will

- [ ] option1 \n- [X] option2

So upper or lower case "X" makes a difference and spaces in the brackets can make a difference.

Expected result:

Both to send a slack message with properly formatted results (or at least not error and send a message even with stripped out or improperly formatting content).

Actual result:

The first markdown text is sent and formatted correctly.

The second does not, it results in this error when trying to post the message:

{
  "code": "slack_webapi_platform_error",
  "data": {
    "ok": false,
    "error": "internal_error",
    "response_metadata": {
      "scopes": [
        "chat:write",
        "users:read",
        "channels:read",
        "groups:read",
        "im:read",
        "mpim:read",
        "im:write",
        "chat:write.public"
      ],
      "acceptedScopes": [
        "chat:write"
      ]
    }
  }
}

Requirements

For general questions/issues about Slack API platform or its server-side, could you submit questions at https://my.slack.com/help/requests/new instead. 🙇

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