Remove use of bash

Library/Homebrew/dev-cmd/extract.rb

@@ -81,7 +81,8 @@ module Homebrew
 
         Look through repository history to find the most recent version of <formula> and
         create a copy in <tap>`/Formula/`<formula>`@`<version>`.rb`. If the tap is not
-        installed yet, attempt to install/clone the tap before continuing.
+        installed yet, attempt to install/clone the tap before continuing. To extract
+        a <formula> from a tap that is not homebrew/core use <user>/<repo>/<formula>.
       EOS
 
       flag "--version=",
@@ -112,7 +113,12 @@ module Homebrew
     destination_tap.install unless destination_tap.installed?
 
     repo = source_tap.path
-    pattern = source_tap.core_tap? ? repo/"Formula/#{name}.rb" : repo/"{,**/}#{name}.rb"
+    pattern = if source_tap.core_tap?
+      [repo/"Formula/#{name}.rb"]
+    else
+      # A formula can technically live in the root directory of a tap or in any of its subdirectories
+      [repo/"#{name}.rb", repo/"**/#{name}.rb"]
+    end
 
     if args.version
       ohai "Searching repository history"
@@ -138,6 +144,7 @@ module Homebrew
       end
       odie "Could not find #{name}! The formula or version may not have existed." if test_formula.nil?
     else
+      # Search in the root directory of <repo> as well as recursively in all of its subdirectories
       files = Dir[repo/"{,**/}"].map do |dir|
         Pathname.glob(["#{dir}/#{name}.rb"]).find(&:file?)
       end.compact

Library/Homebrew/test/dev-cmd/extract_spec.rb

 describe "brew extract", :integration_test do
-  it "retrieves the specified version of formula from core tap, defaulting to most recent" do
+  it "retrieves the specified version of formula, defaulting to most recent" do
     path = Tap::TAP_DIRECTORY/"homebrew/homebrew-foo"
     (path/"Formula").mkpath
     target = Tap.from_path(path)
@@ -29,69 +29,4 @@ describe "brew extract", :integration_test do
 
     expect(Formulary.factory(path/"Formula/testball@0.1.rb").version).to be == "0.1"
   end
-
-  it "retrieves the specified version of formula from a tap other than core, defaulting to most recent" do
-    destination = Tap::TAP_DIRECTORY/"homebrew/homebrew-foo"
-    (destination/"Formula").mkpath
-    destination_tap = Tap.from_path(destination)
-
-    source = Tap::TAP_DIRECTORY/"homebrew/homebrew-bar"
-    source.mkpath
-    source_tap = Tap.from_path(source)
-
-    tarball = if OS.linux?
-      TEST_FIXTURE_DIR/"tarballs/testball-0.1-linux.tbz"
-    else
-      TEST_FIXTURE_DIR/"tarballs/testball-0.1.tbz"
-    end
-
-    content = <<~RUBY
-      desc "Some test"
-      homepage "https://brew.sh/testball"
-      url "file://#{tarball}"
-      sha256 "#{tarball.sha256}"
-
-      option "with-foo", "Build with foo"
-
-      def install
-        (prefix/"foo"/"test").write("test") if build.with? "foo"
-        prefix.install Dir["*"]
-        (buildpath/"test.c").write \
-          "#include <stdio.h>\\nint main(){return printf(\\"test\\");}"
-        bin.mkpath
-        system ENV.cc, "test.c", "-o", bin/"test"
-      end
-    RUBY
-
-    formula_file = source_tap.path/"testball.rb"
-    formula_file.write <<~RUBY
-      class Testball < Formula
-        #{content}
-      end
-    RUBY
-
-    source_tap.path.cd do
-      system "git", "init"
-      system "git", "add", "--all"
-      system "git", "commit", "-m", "testball 0.1"
-      contents = File.read(formula_file)
-      contents.gsub!("testball-0.1", "testball-0.2")
-      File.write(formula_file, contents)
-      system "git", "add", "--all"
-      system "git", "commit", "-m", "testball 0.2"
-    end
-    expect { brew "extract", "homebrew/bar/testball", destination_tap.name }
-      .to be_a_success
-
-    expect(destination/"Formula/testball@0.2.rb").to exist
-
-    expect(Formulary.factory(destination/"Formula/testball@0.2.rb").version).to be == "0.2"
-
-    expect { brew "extract", "homebrew/bar/testball", destination_tap.name, "--version=0.1" }
-      .to be_a_success
-
-    expect(destination/"Formula/testball@0.1.rb").to exist
-
-    expect(Formulary.factory(destination/"Formula/testball@0.1.rb").version).to be == "0.1"
-  end
 end

Library/Homebrew/utils/git.rb

@@ -4,7 +4,11 @@ module Git
   module_function
 
   def last_revision_commit_of_file(repo, file, before_commit: nil)
-    args = [before_commit.nil? ? "--skip=1" : before_commit.split("..").first]
+    args = if before_commit.nil?
+      ["--skip=1"]
+    else
+      [before_commit.split("..").first]
+    end
 
     out, = Open3.capture3(
       HOMEBREW_SHIMS_PATH/"scm/git", "-C", repo,
@@ -14,17 +18,26 @@ module Git
     out.chomp
   end
 
-  def last_revision_commit_of_files(repo, file, before_commit: nil)
-    args = [before_commit.nil? ? "--skip=1" : before_commit.split("..").first]
+  def last_revision_commit_of_files(repo, files, before_commit: nil)
+    args = if before_commit.nil?
+      ["--skip=1"]
+    else
+      [before_commit.split("..").first]
+    end
 
-    cmd = [
-      HOMEBREW_SHIMS_PATH/"scm/git", "-C", repo,
-      "log", "--format=%h", "--abbrev=7", "--max-count=1", "--name-only",
-      *args, "--", file
-    ]
-    out, = Open3.capture3("/bin/bash", "-c", cmd.join(" "))
-    rev, *files = out.chomp.split(/\n/).reject(&:empty?)
-    [rev, files]
+    # git log output format:
+    #   <commit_hash>
+    #   <file_path1>
+    #   <file_path2>
+    #   ...
+    # return [<commit_hash>, [file_path1, file_path2, ...]]
+    out, = Open3.capture3(
+      HOMEBREW_SHIMS_PATH/"scm/git", "-C", repo, "log",
+      "--pretty=format:%h", "--abbrev=7", "--max-count=1",
+      "--diff-filter=d", "--name-only", *args, "--", *files
+    )
+    rev, *paths = out.chomp.split(/\n/).reject(&:empty?)
+    [rev, paths]
   end
 
   def last_revision_of_file(repo, file, before_commit: nil)

docs/Manpage.md

@@ -785,7 +785,8 @@ Homebrew repository for editing if no *`formula`* is provided.
 
 Look through repository history to find the most recent version of *`formula`* and
 create a copy in *`tap`*`/Formula/`*`formula`*`@`*`version`*`.rb`. If the tap is not
-installed yet, attempt to install/clone the tap before continuing.
+installed yet, attempt to install/clone the tap before continuing. To extract a
+*`formula`* from a tap that is not homebrew/core use *`user`*/*`repo`*/*`formula`*.
 
 * `--version`:
   Extract the provided *`version`* of *`formula`* instead of the most recent.

manpages/brew.1

@@ -985,7 +985,7 @@ Generate the new formula in the provided tap, specified as \fIuser\fR\fB/\fR\fIr
 Open a formula in the editor set by \fBEDITOR\fR or \fBHOMEBREW_EDITOR\fR, or open the Homebrew repository for editing if no \fIformula\fR is provided\.
 .
 .SS "\fBextract\fR [\fIoptions\fR] \fIformula\fR \fItap\fR"
-Look through repository history to find the most recent version of \fIformula\fR and create a copy in \fItap\fR\fB/Formula/\fR\fIformula\fR\fB@\fR\fIversion\fR\fB\.rb\fR\. If the tap is not installed yet, attempt to install/clone the tap before continuing\.
+Look through repository history to find the most recent version of \fIformula\fR and create a copy in \fItap\fR\fB/Formula/\fR\fIformula\fR\fB@\fR\fIversion\fR\fB\.rb\fR\. If the tap is not installed yet, attempt to install/clone the tap before continuing\. To extract a \fIformula\fR from a tap that is not homebrew/core use \fIuser\fR/\fIrepo\fR/\fIformula\fR\.
 .
 .TP
 \fB\-\-version\fR