Related discussions:

• https://github.com/orgs/goreleaser/discussions/5563
• https://github.com/orgs/goreleaser/discussions/5796

Following up on our previous discussions, I am currently working on migrating our internal formulas to Casks.

Current Private Formula Setup

I originally used a custom download strategy for our Formulas to distribute them privately via the GitHub API.
This was configurable in GoReleaser using download_strategy and custom_require.

Problem Encountered During Migration to a Private Cask

To distribute a Cask in the same way, I need to build the URL dynamically, as shown in the example below.
https://github.com/sushichan044/homebrew-experimental-tap/blob/d0351ea9ab480fc56b7038898b7bd49eedbc591f/Casks/example-go-cask.rb#L13-L34

This is the approach introduced in the Cask Cookbook as "Arbitrary Ruby methods".
https://docs.brew.sh/Cask-Cookbook#arbitrary-ruby-methods

Currently, this cannot be done with GoReleaser.
This is because the Ruby code set in custom_block is placed below the OS-specific URL settings.
As a result, the Custom Module is out of scope and inaccessible at the time the URL is constructed.

Proposed Changes

Option 1

One option is to place the Ruby block set by custom_block as high up as possible. For example, it could be placed between the livecheck and binary stanzas.

This makes the Ruby module defined in custom_block accessible when the URL is constructed.

Option 2 ( Alternative )

Alternatively, it is also possible to use a block to dynamically construct the URL in a Homebrew Cask, as shown below.

https://docs.brew.sh/Cask-Cookbook#writing-the-block

I tried this implementation pattern locally, but the URL DSL was so expressive that it seemed extremely difficult to map into the Go Template.
This block pattern is required to detect the download URL from the page's HTML dynamically, but it seems we don't need to support this feature unless there is strong demand for it.