Merge pull request #20601 from Homebrew/copilot/fix-20600

Add cask support to `brew unpack` command

Author: p-linnane

Library/Homebrew/dev-cmd/unpack.rb

@@ -5,6 +5,8 @@
 require "fileutils"
 require "stringio"
 require "formula"
+require "cask/download"
+require "unpack_strategy"
 
 module Homebrew
   module DevCmd
@@ -13,7 +15,7 @@ class Unpack < AbstractCommand
 
       cmd_args do
         description <<~EOS
-          Unpack the source files for <formula> into subdirectories of the current
+          Unpack the files for the <formula> or <cask> into subdirectories of the current
           working directory.
         EOS
         flag   "--destdir=",
@@ -25,15 +27,28 @@ class Unpack < AbstractCommand
                             "patches for the software."
         switch "-f", "--force",
                description: "Overwrite the destination directory if it already exists."
+        switch "--formula", "--formulae",
+               description: "Treat all named arguments as formulae."
+        switch "--cask", "--casks",
+               description: "Treat all named arguments as casks."
 
         conflicts "--git", "--patch"
+        conflicts "--formula", "--cask"
+        conflicts "--cask", "--patch"
+        conflicts "--cask", "--git"
 
-        named_args :formula, min: 1
+        named_args [:formula, :cask], min: 1
       end
 
       sig { override.void }
       def run
-        formulae = args.named.to_formulae
+        formulae_and_casks = if args.casks?
+          args.named.to_formulae_and_casks(only: :cask)
+        elsif args.formulae?
+          args.named.to_formulae_and_casks(only: :formula)
+        else
+          args.named.to_formulae_and_casks
+        end
 
         if (dir = args.destdir)
           unpack_dir = Pathname.new(dir).expand_path
@@ -44,34 +59,69 @@ def run
 
         odie "Cannot write to #{unpack_dir}" unless unpack_dir.writable?
 
-        formulae.each do |f|
-          stage_dir = unpack_dir/"#{f.name}-#{f.version}"
+        formulae_and_casks.each do |formula_or_cask|
+          if formula_or_cask.is_a?(Cask::Cask)
+            unpack_cask(formula_or_cask, unpack_dir)
+          elsif (formula = T.cast(formula_or_cask, Formula))
+            unpack_formula(formula, unpack_dir)
+          end
+        end
+      end
 
-          if stage_dir.exist?
-            odie "Destination #{stage_dir} already exists!" unless args.force?
+      private
 
-            rm_rf stage_dir
-          end
+      sig { params(formula: Formula, unpack_dir: Pathname).void }
+      def unpack_formula(formula, unpack_dir)
+        stage_dir = unpack_dir/"#{formula.name}-#{formula.version}"
 
-          oh1 "Unpacking #{Formatter.identifier(f.full_name)} to: #{stage_dir}"
+        if stage_dir.exist?
+          odie "Destination #{stage_dir} already exists!" unless args.force?
 
-          # show messages about tar
-          with_env VERBOSE: "1" do
-            f.brew do
-              f.patch if args.patch?
-              cp_r getwd, stage_dir, preserve: true
-            end
-          end
+          rm_rf stage_dir
+        end
 
-          next unless args.git?
+        oh1 "Unpacking #{Formatter.identifier(formula.full_name)} to: #{stage_dir}"
 
-          ohai "Setting up Git repository"
-          cd(stage_dir) do
-            system "git", "init", "-q"
-            system "git", "add", "-A"
-            system "git", "commit", "-q", "-m", "brew-unpack"
+        # show messages about tar
+        with_env VERBOSE: "1" do
+          formula.brew do
+            formula.patch if args.patch?
+            cp_r getwd, stage_dir, preserve: true
           end
         end
+
+        return unless args.git?
+
+        ohai "Setting up Git repository"
+        cd(stage_dir) do
+          system "git", "init", "-q"
+          system "git", "add", "-A"
+          system "git", "commit", "-q", "-m", "brew-unpack"
+        end
+      end
+
+      sig { params(cask: Cask::Cask, unpack_dir: Pathname).void }
+      def unpack_cask(cask, unpack_dir)
+        stage_dir = unpack_dir/"#{cask.token}-#{cask.version}"
+
+        if stage_dir.exist?
+          odie "Destination #{stage_dir} already exists!" unless args.force?
+
+          rm_rf stage_dir
+        end
+
+        oh1 "Unpacking #{Formatter.identifier(cask.full_name)} to: #{stage_dir}"
+
+        download = Cask::Download.new(cask, quarantine: true)
+
+        downloaded_path = if download.downloaded?
+          download.cached_download
+        else
+          download.fetch(quiet: false)
+        end
+
+        stage_dir.mkpath
+        UnpackStrategy.detect(downloaded_path).extract_nestedly(to: stage_dir, verbose: true)
       end
     end
   end

Library/Homebrew/sorbet/rbi/dsl/homebrew/dev_cmd/unpack.rbi

@@ -16,4 +16,15 @@
       expect(path/"testball-0.1").to be_a_directory
     end
   end
+
+  it "unpacks a given Cask's archive", :integration_test do
+    caffeine_cask = Cask::CaskLoader.load(cask_path("local-caffeine"))
+
+    mktmpdir do |path|
+      expect { brew "unpack", cask_path("local-caffeine"), "--destdir=#{path}" }
+        .to be_a_success
+
+      expect(path/"local-caffeine-#{caffeine_cask.version}").to be_a_directory
+    end
+  end
 end