utils/git_repository: add ::git_branch and ::git_commit_message

Library/Homebrew/extend/git_repository.rb

@@ -18,9 +18,7 @@ def git?
   # Gets the URL of the Git origin remote.
   sig { returns(T.nilable(String)) }
   def git_origin
-    return if !git? || !Utils::Git.available?
-
-    Utils.popen_read(Utils::Git.git, "config", "--get", "remote.origin.url", chdir: self).chomp.presence
+    popen_git("config", "--get", "remote.origin.url")
   end
 
   # Sets the URL of the Git origin remote.
@@ -47,26 +45,19 @@ def git_short_head(length: nil, safe: false)
   # Gets the relative date of the last commit, e.g. "1 hour ago"
   sig { returns(T.nilable(String)) }
   def git_last_commit
-    return if !git? || !Utils::Git.available?
-
-    Utils.popen_read(Utils::Git.git, "show", "-s", "--format=%cr", "HEAD", chdir: self).chomp.presence
+    popen_git("show", "-s", "--format=%cr", "HEAD")
   end
 
   # Gets the name of the currently checked-out branch, or HEAD if the repository is in a detached HEAD state.
-  sig { returns(T.nilable(String)) }
-  def git_branch
-    return if !git? || !Utils::Git.available?
-
-    Utils.popen_read(Utils::Git.git, "rev-parse", "--abbrev-ref", "HEAD", chdir: self).chomp.presence
+  sig { params(safe: T::Boolean).returns(T.nilable(String)) }
+  def git_branch(safe: false)
+    popen_git("rev-parse", "--abbrev-ref", "HEAD", safe: safe)
   end
 
   # Gets the name of the default origin HEAD branch.
   sig { returns(T.nilable(String)) }
   def git_origin_branch
-    return if !git? || !Utils::Git.available?
-
-    Utils.popen_read(Utils::Git.git, "symbolic-ref", "-q", "--short", "refs/remotes/origin/HEAD", chdir: self)
-         .chomp.presence&.split("/")&.last
+    popen_git("symbolic-ref", "-q", "--short", "refs/remotes/origin/HEAD")&.split("/")&.last
   end
 
   # Returns true if the repository's current branch matches the default origin branch.
@@ -78,23 +69,19 @@ def git_default_origin_branch?
   # Returns the date of the last commit, in YYYY-MM-DD format.
   sig { returns(T.nilable(String)) }
   def git_last_commit_date
-    return if !git? || !Utils::Git.available?
-
-    Utils.popen_read(Utils::Git.git, "show", "-s", "--format=%cd", "--date=short", "HEAD", chdir: self).chomp.presence
+    popen_git("show", "-s", "--format=%cd", "--date=short", "HEAD")
   end
 
   # Gets the full commit message of the specified commit, or of the HEAD commit if unspecified.
-  sig { params(commit: String).returns(T.nilable(String)) }
-  def git_commit_message(commit = "HEAD")
-    return if !git? || !Utils::Git.available?
-
-    Utils.popen_read(Utils::Git.git, "log", "-1", "--pretty=%B", commit, "--", chdir: self, err: :out).strip.presence
+  sig { params(commit: String, safe: T::Boolean).returns(T.nilable(String)) }
+  def git_commit_message(commit = "HEAD", safe: false)
+    popen_git("log", "-1", "--pretty=%B", commit, "--", safe: safe, err: :out)&.strip
   end
 
   private
 
-  sig { params(args: T.untyped, safe: T::Boolean).returns(T.nilable(String)) }
-  def popen_git(*args, safe: false)
+  sig { params(args: T.untyped, safe: T::Boolean, err: T.nilable(Symbol)).returns(T.nilable(String)) }
+  def popen_git(*args, safe: false, err: nil)
     unless git?
       return unless safe
 
@@ -107,6 +94,6 @@ def popen_git(*args, safe: false)
       raise "Git is unavailable"
     end
 
-    T.unsafe(Utils).popen_read(Utils::Git.git, *args, safe: safe, chdir: self).chomp.presence
+    T.unsafe(Utils).popen_read(Utils::Git.git, *args, safe: safe, chdir: self, err: err).chomp.presence
   end
 end

Library/Homebrew/test/utils/git_repository_spec.rb

@@ -37,20 +37,21 @@
       system "git", "init"
       Pathname("README.md").write("README")
       system "git", "add", "README.md"
-      system "git", "commit", "-m", "File added"
+      system "git", "commit", "-m", commit_message
+      system "git", "checkout", "-b", branch_name
     end
   end
 
+  let(:commit_message) { "File added" }
+  let(:branch_name) { "test-branch" }
+
   let(:head_revision) { HOMEBREW_CACHE.cd { `git rev-parse HEAD`.chomp } }
   let(:short_head_revision) { HOMEBREW_CACHE.cd { `git rev-parse --short HEAD`.chomp } }
 
-  describe ".git_head" do
-    it "returns the revision at HEAD if repo parameter is specified" do
+  describe "::git_head" do
+    it "returns the revision at HEAD" do
       expect(described_class.git_head(HOMEBREW_CACHE)).to eq(head_revision)
       expect(described_class.git_head(HOMEBREW_CACHE, length: 5)).to eq(head_revision[0...5])
-    end
-
-    it "returns the revision at HEAD if repo parameter is omitted" do
       HOMEBREW_CACHE.cd do
         expect(described_class.git_head).to eq(head_revision)
         expect(described_class.git_head(length: 5)).to eq(head_revision[0...5])
@@ -60,13 +61,10 @@
     include_examples "git_repository helper function", :git_head
   end
 
-  describe ".git_short_head" do
-    it "returns the short revision at HEAD if repo parameter is specified" do
+  describe "::git_short_head" do
+    it "returns the short revision at HEAD" do
       expect(described_class.git_short_head(HOMEBREW_CACHE)).to eq(short_head_revision)
       expect(described_class.git_short_head(HOMEBREW_CACHE, length: 5)).to eq(head_revision[0...5])
-    end
-
-    it "returns the short revision at HEAD if repo parameter is omitted" do
       HOMEBREW_CACHE.cd do
         expect(described_class.git_short_head).to eq(short_head_revision)
         expect(described_class.git_short_head(length: 5)).to eq(head_revision[0...5])
@@ -75,4 +73,28 @@
 
     include_examples "git_repository helper function", :git_short_head
   end
+
+  describe "::git_branch" do
+    include_examples "git_repository helper function", :git_branch
+
+    it "returns the current Git branch" do
+      expect(described_class.git_branch(HOMEBREW_CACHE)).to eq(branch_name)
+      HOMEBREW_CACHE.cd do
+        expect(described_class.git_branch).to eq(branch_name)
+      end
+    end
+  end
+
+  describe "::git_commit_message" do
+    include_examples "git_repository helper function", :git_commit_message
+
+    it "returns the commit message of HEAD" do
+      expect(described_class.git_commit_message(HOMEBREW_CACHE)).to eq(commit_message)
+      expect(described_class.git_commit_message(HOMEBREW_CACHE, commit: head_revision)).to eq(commit_message)
+      HOMEBREW_CACHE.cd do
+        expect(described_class.git_commit_message).to eq(commit_message)
+        expect(described_class.git_commit_message(commit: head_revision)).to eq(commit_message)
+      end
+    end
+  end
 end

Library/Homebrew/utils/git_repository.rb

@@ -4,6 +4,7 @@
 module Utils
   extend T::Sig
 
+  # Gets the full commit hash of the HEAD commit.
   sig {
     params(
       repo:   T.any(String, Pathname),
@@ -18,6 +19,7 @@ def self.git_head(repo = Pathname.pwd, length: nil, safe: true)
     repo.git_head(safe: safe)
   end
 
+  # Gets a short commit hash of the HEAD commit.
   sig {
     params(
       repo:   T.any(String, Pathname),
@@ -29,4 +31,29 @@ def self.git_short_head(repo = Pathname.pwd, length: nil, safe: true)
     repo = Pathname(repo).extend(GitRepositoryExtension)
     repo.git_short_head(length: length, safe: safe)
   end
+
+  # Gets the name of the currently checked-out branch, or HEAD if the repository is in a detached HEAD state.
+  sig {
+    params(
+      repo: T.any(String, Pathname),
+      safe: T::Boolean,
+    ).returns(T.nilable(String))
+  }
+  def self.git_branch(repo = Pathname.pwd, safe: true)
+    repo = Pathname(repo).extend(GitRepositoryExtension)
+    repo.git_branch(safe: safe)
+  end
+
+  # Gets the full commit message of the specified commit, or of the HEAD commit if unspecified.
+  sig {
+    params(
+      repo:   T.any(String, Pathname),
+      commit: String,
+      safe:   T::Boolean,
+    ).returns(T.nilable(String))
+  }
+  def self.git_commit_message(repo = Pathname.pwd, commit: "HEAD", safe: true)
+    repo = Pathname(repo).extend(GitRepositoryExtension)
+    repo.git_commit_message(commit, safe: safe)
+  end
 end