URL do block with custom downloader strategy

[marblenix]

The docs hint at how to do this, but don't provide an example.

https://github.com/Homebrew/homebrew-cask/blob/master/doc/cask_language_reference/stanzas/url.md#mixing-additional-url-parameters-with-the-block-syntax

In rare cases, you might need to set URL parameters like cookies or referer while also using the block syntax.

This is possible by returning a two-element array as a block result. The first element of the array must be the download URL; the second element must be a Hash containing the parameters.

But when I try to do this like so:

  url do
    [
      url,
      {using: MyDownloadStrategy}
    ]
  end

I get the following error:

==> Cask::Installer#install
==> Printing caveats
==> Cask::Installer#fetch
Error: Download failed on Cask 'onivim2' with message: wrong number of arguments (given 2, expected 1)
/usr/local/Homebrew/Library/Homebrew/cask/url.rb:38:in `initialize'
/usr/local/Homebrew/Library/Homebrew/cask/dsl.rb:184:in `new'
/usr/local/Homebrew/Library/Homebrew/cask/dsl.rb:184:in `block (2 levels) in url'

I'm sure there's something simple I'm doing wrong here, but I can't for the life of me figure out what.

[SMillerDev]

@Homebrew/cask can you lend a hand here?

[marblenix]

The trouble seems to be in this block of code in dls.rb:

https://github.com/Homebrew/brew/blob/master/Library/Homebrew/cask/dsl.rb#L184

    def url(*args, **options)
      caller_location = caller_locations[0]

      set_unique_stanza(:url, args.empty? && options.empty? && !block_given?) do
        if block_given?
          LazyObject.new { URL.new(*yield, from_block: true, caller_location: caller_location) }
        else
          URL.new(*args, **options, caller_location: caller_location)
        end
      end
    end

URL.new inside the LazyObject is missing **options in the arguments list; adding options to the argument list allowed me to do

  url using: MyDownloadStrategy do
    some_url
  end

If this is actually a bug I'd be happy to open a pull request for this issue.

[vitorgalvao]

If this is actually a bug I'd be happy to open a pull request for this issue.

Might be a bug, yes. Pinging @claui, who first developed the feature.

[marblenix]

I hope it's okay, but I went ahead and made the pull requests, please let me know if I missed something.

• bugfix: Add args and options to lazy url block brew#10548
• Update url.md homebrew-cask#99447