TagBuilder#action doesn't support custom attributes or optional targets

[aviflombaum]

Problem

When creating custom Turbo Stream actions that don't require a target element but
need custom attributes, there's no clean way to generate them from a controller
using turbo_stream.action().

Use Case

We have a custom Turbo Stream action for redirecting from within a Turbo Frame:

// Custom Turbo Stream action                                                    
Turbo.StreamActions.redirect_to = function () {                                  
  const redirectTo = this.getAttribute("redirect_to")                            
  Turbo.visit(redirectTo)                                                        
}

Expected HTML output:

What We Tried

Attempt 1: Pass nil as target with custom attribute
render turbo_stream: turbo_stream.action(:redirect_to, nil, redirect_to: url)
Result: ArgumentError: You invoked render but did not give any of :body, :file,
:html...

Attempt 2: Omit target, pass only custom attribute
render turbo_stream: turbo_stream.action(:redirect_to, redirect_to: url)
Result: ArgumentError: wrong number of arguments (given 1, expected 2..3)

Root Cause

Looking at TagBuilder#action:

def action(name, target, content = nil, method: nil, allow_inferred_rendering:
true, **rendering, &block)
template = render_template(target, content, allow_inferred_rendering:
allow_inferred_rendering, **rendering, &block)
turbo_stream_action_tag name, target: target, template: template, method:
method
end

Two issues:

1. target is a required positional argument
2. Custom attributes in **rendering are not passed through to
   turbo_stream_action_tag

Meanwhile, turbo_stream_action_tag in ActionHelper already supports both optional
targets and custom attributes:

def turbo_stream_action_tag(action, target: nil, targets: nil, template: nil,
**attributes)
# ...
tag.turbo_stream(template, **attributes, action: action)
end

Current Workaround

render turbo_stream: helpers.turbo_stream_action_tag(:redirect_to, redirect_to:
url)

This works but feels like unnecessary indirection when turbo_stream.action()
should handle it.

Proposed Fix

Update TagBuilder#action to:

1. Make target a keyword argument with nil default
2. Accept and pass through custom attributes

def action(name, target: nil, content: nil, method: nil,
allow_inferred_rendering: true, **attributes, &block)
template = render_template(target, content, allow_inferred_rendering:
allow_inferred_rendering, &block)
turbo_stream_action_tag name, target: target, template: template, method:
method, **attributes
end

This would allow:
turbo_stream.action(:redirect_to, redirect_to: url)
turbo_stream.action(:custom_action, target: "my-element", custom_attr: "value")

Breaking Change Consideration

Changing target from positional to keyword would be breaking. An alternative is
to add a new method like action_without_target or detect when first argument is a
symbol/hash, though neither is as clean.

Environment

• turbo-rails 2.0.20
• Rails 8.0