unpack_strategy: add zstd

Library/Homebrew/dependency_collector.rb

@@ -81,6 +81,10 @@ class DependencyCollector
     Dependency.new("xz", tags) unless which("xz")
   end
 
+  def zstd_dep_if_needed(tags)
+    Dependency.new("zstd", tags) unless which("zstd")
+  end
+
   def unzip_dep_if_needed(tags)
     Dependency.new("unzip", tags) unless which("unzip")
   end
@@ -171,6 +175,7 @@ class DependencyCollector
   def parse_url_spec(url, tags)
     case File.extname(url)
     when ".xz"          then xz_dep_if_needed(tags)
+    when ".zst"         then zstd_dep_if_needed(tags)
     when ".zip"         then unzip_dep_if_needed(tags)
     when ".bz2"         then bzip2_dep_if_needed(tags)
     when ".lha", ".lzh" then Dependency.new("lha", tags)

Library/Homebrew/extend/pathname.rb

@@ -231,7 +231,7 @@ class Pathname
     bottle_ext, = HOMEBREW_BOTTLES_EXTNAME_REGEX.match(basename).to_a
     return bottle_ext if bottle_ext
 
-    archive_ext = basename[/(\.(tar|cpio|pax)\.(gz|bz2|lz|xz|Z))\Z/, 1]
+    archive_ext = basename[/(\.(tar|cpio|pax)\.(gz|bz2|lz|xz|zst|Z))\Z/, 1]
     return archive_ext if archive_ext
 
     # Don't treat version numbers as extname.

Library/Homebrew/test/unpack_strategy/zstd_spec.rb

@@ -0,0 +1,10 @@
+# typed: false
+# frozen_string_literal: true
+
+require_relative "shared_examples"
+
+describe UnpackStrategy::Zstd do
+  let(:path) { TEST_FIXTURE_DIR/"cask/container.tar.zst" }
+
+  include_examples "UnpackStrategy::detect"
+end

Library/Homebrew/unpack_strategy.rb

@@ -44,12 +44,13 @@ module UnpackStrategy
 
   def self.strategies
     @strategies ||= [
-      Tar, # Needs to be before Bzip2/Gzip/Xz/Lzma.
+      Tar, # Needs to be before Bzip2/Gzip/Xz/Lzma/Zstd.
       Pax,
       Gzip,
       Dmg, # Needs to be before Bzip2/Xz/Lzma.
       Lzma,
       Xz,
+      Zstd,
       Lzip,
       Air, # Needs to be before `Zip`.
       Jar, # Needs to be before `Zip`.
@@ -203,3 +204,4 @@ require "unpack_strategy/uncompressed"
 require "unpack_strategy/xar"
 require "unpack_strategy/xz"
 require "unpack_strategy/zip"
+require "unpack_strategy/zstd"

Library/Homebrew/unpack_strategy/tar.rb

@@ -20,14 +20,15 @@ module UnpackStrategy
         ".tbz", ".tbz2", ".tar.bz2",
         ".tgz", ".tar.gz",
         ".tlzma", ".tar.lzma",
-        ".txz", ".tar.xz"
+        ".txz", ".tar.xz",
+        ".tar.zst"
       ]
     end
 
     def self.can_extract?(path)
       return true if path.magic_number.match?(/\A.{257}ustar/n)
 
-      return false unless [Bzip2, Gzip, Lzip, Xz].any? { |s| s.can_extract?(path) }
+      return false unless [Bzip2, Gzip, Lzip, Xz, Zstd].any? { |s| s.can_extract?(path) }
 
       # Check if `tar` can list the contents, then it can also extract it.
       stdout, _, status = system_command("tar", args: ["--list", "--file", path], print_stderr: false)
@@ -39,12 +40,12 @@ module UnpackStrategy
     sig { override.params(unpack_dir: Pathname, basename: Pathname, verbose: T::Boolean).returns(T.untyped) }
     def extract_to_dir(unpack_dir, basename:, verbose:)
       Dir.mktmpdir do |tmpdir|
-        tar_path = path
-
-        if DependencyCollector.tar_needs_xz_dependency? && Xz.can_extract?(path)
-          tmpdir = Pathname(tmpdir)
-          Xz.new(path).extract(to: tmpdir, verbose: verbose)
-          tar_path = tmpdir.children.first
+        tar_path = if DependencyCollector.tar_needs_xz_dependency? && Xz.can_extract?(path)
+          subextract(Xz, Pathname(tmpdir), verbose)
+        elsif Zstd.can_extract?(path)
+          subextract(Zstd, Pathname(tmpdir), verbose)
+        else
+          path
         end
 
         system_command! "tar",
@@ -54,5 +55,13 @@ module UnpackStrategy
                         verbose: verbose
       end
     end
+
+    sig {
+      params(extractor: T.any(T.class_of(Xz), T.class_of(Zstd)), dir: Pathname, verbose: T::Boolean).returns(Pathname)
+    }
+    def subextract(extractor, dir, verbose)
+      extractor.new(path).extract(to: dir, verbose: verbose)
+      T.must(dir.children.first)
+    end
   end
 end

Library/Homebrew/unpack_strategy/zstd.rb

@@ -0,0 +1,38 @@
+# typed: true
+# frozen_string_literal: true
+
+module UnpackStrategy
+  # Strategy for unpacking zstd archives.
+  class Zstd
+    extend T::Sig
+
+    include UnpackStrategy
+
+    using Magic
+
+    sig { returns(T::Array[String]) }
+    def self.extensions
+      [".zst"]
+    end
+
+    def self.can_extract?(path)
+      path.magic_number.match?(/\x28\xB5\x2F\xFD/n)
+    end
+
+    def dependencies
+      @dependencies ||= [Formula["zstd"]]
+    end
+
+    private
+
+    sig { override.params(unpack_dir: Pathname, basename: Pathname, verbose: T::Boolean).returns(T.untyped) }
+    def extract_to_dir(unpack_dir, basename:, verbose:)
+      FileUtils.cp path, unpack_dir/basename, preserve: true
+      quiet_flags = verbose ? [] : ["-q"]
+      system_command! "unzstd",
+                      args:    [*quiet_flags, "-T0", "--", unpack_dir/basename],
+                      env:     { "PATH" => PATH.new(Formula["zstd"].opt_bin, ENV["PATH"]) },
+                      verbose: verbose
+    end
+  end
+end