Can't not supply an expires in /sharing/create_shared_link_with_settings

[ncw]

Describe the bug

I'd like to create a sharing link with supplying sharing.SharedLinkSettings but without supplying sharing.SharedLinkSettings.Expires

To Reproduce

Submit a request like this

	createArg := sharing.CreateSharedLinkWithSettingsArg{
		Path: absPath,
		Settings: &sharing.SharedLinkSettings{
			RequestedVisibility: &sharing.RequestedVisibility{
				dropbox.Tagged{sharing.RequestedVisibilityPublic},
			},
			Audience: &sharing.LinkAudience{
				dropbox.Tagged{sharing.LinkAudiencePublic},
			},
			Access: &sharing.RequestedLinkAccessLevel{
				dropbox.Tagged{sharing.RequestedLinkAccessLevelViewer},
			},
		},
	}
	var linkRes sharing.IsSharedLinkMetadata
	linkRes, err = f.sharing.CreateSharedLinkWithSettings(&createArg)

The actual JSON submitted to the endpoint is this (formatted for readability)

{
  "path": "/hello.txt",
  "settings": {
    "requested_visibility": {
      ".tag": "public"
    },
    "expires": "0001-01-01T00:00:00Z",
    "audience": {
      ".tag": "public"
    },
    "access": {
      ".tag": "viewer"
    }
  }
}

Note the "expires": "0001-01-01T00:00:00Z"

Expected Behavior

I would expect the expires field to be missing or possibly empty string

Actual Behavior

There may be a special case for this in the dropbox API, but expires is not supported by a non enterprise dropbox, so if you supply anything in the expires you get

{
  "error_summary": "settings_error/not_authorized/.",
  "error": {
    ".tag": "settings_error",
    "settings_error": {
      ".tag": "not_authorized"
    }
  }
}

Versions

This reproduces with the SDK at master

Additional context

Because time.Time is struct, its empty value is all the fields empty, hence the "0001-01-01T00:00:00Z".

A patch like this does fix the problem - making the time.Time into a pointer type so it can be omitted properly.

diff --git a/dropbox/sharing/types.go b/dropbox/sharing/types.go
index 085cda4..6ab9870 100644
--- a/dropbox/sharing/types.go
+++ b/dropbox/sharing/types.go
@@ -3922,7 +3922,7 @@ type SharedLinkSettings struct {
        LinkPassword string `json:"link_password,omitempty"`
        // Expires : Expiration time of the shared link. By default the link won't
        // expire.
-       Expires time.Time `json:"expires,omitempty"`
+       Expires *time.Time `json:"expires,omitempty"`
        // Audience : The new audience who can benefit from the access level
        // specified by the link's access level specified in the `link_access_level`
        // field of `LinkPermissions`. This is used in conjunction with team

However that needs to be done in the generator. It is also not backwards compatible.

An alternate patch would be to make a special case MarshalJSON for the Expires which checked expires = time.Time{} and omitted it.

[rajatgoel]

So as long as we bump the major version when we make the next release, changing the type should be fine? If so, I think it should be fine to land #76.