MethodsClientImpl oauthV2Access: redirect_uri should be optional

[natevaughan]

Issue Type

[ x ] Bug
[ ] Enhancement / Feature request
[ ] Question
[ ] Documentation

Description

Hi @seratch !

I'm seeing this error when sending a null redirect_uri in OauthV2AccessRequestBuilder:

java.lang.IllegalArgumentException: Parameter specified as non-null is null: method okhttp3.FormBody$Builder.add, parameter value

It seems OKHTTP's form builder specifies that all param values must be non-null.

I think simply wrapping this line in MethodsClientImpl with a null check should suffice:

if (req.getRedirectUri() != null) {
    form.add("redirect_uri", req.getRedirectUri());
}

Filing this as a bug due to a mismatch between Slack's Oauth V2 api documentation, which specifies redirect_uri as optional.

I should mention that I previously was using a hand-cooked Slack API client and Oauth worked fine without redirect_uri.

The issue is reproducible in:

• Module Version: 1.0.7
• JDK Version: Zulu 1.8.0_232

The steps to reproduce are:

1. Use the following sample (Kotlin) code with a valid code, clientId, and clientSecret (do not set redirect_uri):

    val builder = OAuthV2AccessRequest.builder()
        .code(code)				
        .clientId(clientId)
        .clientSecret(clientSecret)

    val response = methods.oauthV2Access(builder.build())

2. The expected result is the request should succeed.

3. The actual result is the following exception from OKHTTP:

java.lang.IllegalArgumentException: Parameter specified as non-null is null: method okhttp3.FormBody$Builder.add, parameter value
        at okhttp3.FormBody$Builder.add(FormBody.kt) ~[okhttp-4.6.0.jar!/:na]
        at com.slack.api.methods.impl.MethodsClientImpl.oauthV2Access(MethodsClientImpl.java:1638) ~[slack-api-client-1.0.7.jar!/:1.0.7]

Thank you for your amazing work!

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

[seratch]

@natevaughan Thanks for reporting this. You're right. I will be fixing this very soon.

[seratch]

Thanks again. I will be releasing a new patch version today (+09:00)

[natevaughan]

Thank you @seratch, amazing work at amazing speed!