From b0f5b5d90bb0a47724e622aa7afd09e747cd4662 Mon Sep 17 00:00:00 2001
From: Shane da Silva <shane@dasilva.io>
Date: Tue, 10 Nov 2026 22:32:53 -0800
Subject: [PATCH 1/2] Complete branch coverage and enforce aggregated coverage

---
 .github/workflows/tests.yml                   |  4 +-
 AGENTS.md                                     |  4 +-
 lib/overcommit/cli.rb                         |  4 +-
 .../hook/pre_commit/chamber_verification.rb   |  6 +-
 .../hook/pre_commit/php_cs_fixer.rb           |  4 +-
 lib/overcommit/hook/pre_commit/php_lint.rb    | 11 +--
 lib/overcommit/hook_context/pre_push.rb       |  2 +-
 lib/overcommit/installer.rb                   |  2 -
 lib/overcommit/utils/messages_utils.rb        |  2 -
 script/check_coverage.rb                      | 21 +++++-
 spec/coverage_check_spec.rb                   | 69 +++++++++++++++++++
 spec/overcommit/cli_errors_spec.rb            | 23 +++++++
 .../configuration_validator_spec.rb           | 11 +++
 spec/overcommit/gem_plugin_spec.rb            |  6 ++
 spec/overcommit/git_config_spec.rb            |  9 +++
 spec/overcommit/git_repo_spec.rb              | 52 ++++++++++++++
 .../hook/post_commit/git_guilt_spec.rb        |  7 ++
 .../hook/pre_commit/bundle_check_spec.rb      | 10 +++
 .../hook/pre_commit/case_conflicts_spec.rb    |  7 ++
 .../pre_commit/chamber_verification_spec.rb   | 12 ++++
 spec/overcommit/hook/pre_commit/dogma_spec.rb |  7 ++
 .../pre_commit/execute_permissions_spec.rb    | 15 ++++
 spec/overcommit/hook/pre_commit/flay_spec.rb  | 17 +++++
 .../hook/pre_commit/foodcritic_spec.rb        | 18 +++++
 .../hook/pre_commit/herb_lint_spec.rb         | 15 ++++
 spec/overcommit/hook/pre_commit/jscs_spec.rb  |  5 ++
 .../hook/pre_commit/line_endings_spec.rb      | 21 ++++++
 .../hook/pre_commit/phpcs_fixer_spec.rb       |  5 ++
 spec/overcommit/hook/pre_commit/phpcs_spec.rb | 12 ++++
 .../hook/pre_commit/ruby_syntax_spec.rb       |  8 +++
 .../hook/pre_commit/scss_lint_spec.rb         | 14 ++++
 .../hook/pre_commit/w3c_css_spec.rb           | 12 ++++
 .../hook/pre_commit/w3c_html_spec.rb          | 11 +++
 .../hook/pre_commit/yard_coverage_spec.rb     | 13 ++++
 .../hook/pre_commit/yarn_check_spec.rb        | 11 +++
 .../hook/prepare_commit_msg/base_spec.rb      |  6 ++
 .../prepare_commit_msg/replace_branch_spec.rb | 10 +++
 spec/overcommit/hook_context/base_spec.rb     |  7 ++
 .../helpers/hide_unstaged_changes_spec.rb     | 12 ++++
 .../hook_context/post_commit_spec.rb          |  6 ++
 .../hook_context/pre_commit_spec.rb           | 16 +++++
 spec/overcommit/hook_context/pre_push_spec.rb | 13 ++++
 .../hook_context/pre_rebase_spec.rb           |  7 ++
 spec/overcommit/hook_runner_spec.rb           | 28 ++++++++
 spec/overcommit/hook_signer_files_spec.rb     |  5 ++
 spec/overcommit/installer_spec.rb             | 16 +++++
 spec/overcommit/logger_spec.rb                |  5 ++
 spec/overcommit/message_processor_spec.rb     |  8 +++
 spec/overcommit/printer_spec.rb               |  6 ++
 spec/overcommit/signature_spec.rb             |  9 +++
 spec/overcommit/subprocess_spec.rb            |  5 ++
 spec/overcommit/utils/messages_errors_spec.rb |  6 ++
 spec/overcommit/utils_errors_spec.rb          | 29 ++++++++
 53 files changed, 619 insertions(+), 25 deletions(-)

diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 625c918f..66708031 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -125,8 +125,8 @@ jobs:
           pattern: coverage-*
           path: coverage
 
-      - name: Require 100% combined line coverage
-        run: ruby script/check_coverage.rb coverage/*/lcov.info
+      - name: Require 100% combined line and branch coverage
+        run: ruby script/check_coverage.rb --branches coverage/*/lcov.info
 
       # Shard assignments shift when examples are added. Compare the complete
       # suite's coverage rather than unrelated fractions from individual shards.
diff --git a/AGENTS.md b/AGENTS.md
index 24a2a777..a250020c 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -1,6 +1,8 @@
 # Repository guidance
 
-- Maintain **100% line coverage** across the complete test suite. Add thorough
+- Maintain **100% line and branch coverage**, aggregated across the complete
+  test suite and all CI platforms, Ruby versions, and shards. Individual shards
+  need not reach 100%; the combined coverage report must. Add thorough
   regression tests for new behavior and failure paths; do not exclude production
   code from coverage or lower the threshold to make checks pass.
 - Preserve existing tests unless they specifically test an implementation that
diff --git a/lib/overcommit/cli.rb b/lib/overcommit/cli.rb
index d889a353..bc11b993 100644
--- a/lib/overcommit/cli.rb
+++ b/lib/overcommit/cli.rb
@@ -21,8 +21,6 @@ def run # rubocop:disable Metrics/MethodLength
       parse_arguments
 
       case @options[:action]
-      when :install, :uninstall
-        install_or_uninstall
       when :template_dir
         print_template_directory_path
       when :sign
@@ -31,6 +29,8 @@ def run # rubocop:disable Metrics/MethodLength
         run_all
       when :diff
         diff
+      else
+        install_or_uninstall
       end
     rescue Overcommit::Exceptions::ConfigurationSignatureChanged => e
       puts e
diff --git a/lib/overcommit/hook/pre_commit/chamber_verification.rb b/lib/overcommit/hook/pre_commit/chamber_verification.rb
index 8581c063..a0aca614 100644
--- a/lib/overcommit/hook/pre_commit/chamber_verification.rb
+++ b/lib/overcommit/hook/pre_commit/chamber_verification.rb
@@ -4,7 +4,7 @@ module Overcommit::Hook::PreCommit
   # Runs `chamber sign --verify`.
   #
   # @see https://github.com/thekompanee/chamber/wiki/Git-Commit-Hooks#chamber-verification-pre-commit-hook
-  # rubocop:disable Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
+  # rubocop:disable Metrics/CyclomaticComplexity
   class ChamberVerification < Base
     def run
       approver_name  = config.fetch('approver_name') { 'your approver' }
@@ -22,7 +22,7 @@ def run
         compact.
         join("\n\n")
 
-      output = "\n\n#{output}" unless output.empty?
+      output = "\n\n#{output}"
 
       [
         :warn,
@@ -32,5 +32,5 @@ def run
       ]
     end
   end
-  # rubocop:enable Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
+  # rubocop:enable Metrics/CyclomaticComplexity
 end
diff --git a/lib/overcommit/hook/pre_commit/php_cs_fixer.rb b/lib/overcommit/hook/pre_commit/php_cs_fixer.rb
index 87e63744..2e978b51 100644
--- a/lib/overcommit/hook/pre_commit/php_cs_fixer.rb
+++ b/lib/overcommit/hook/pre_commit/php_cs_fixer.rb
@@ -17,9 +17,7 @@ def run
         output = result.stdout.chomp
         exit_status_sum += result.status
 
-        if result.status
-          messages = output.lstrip.split("\n")
-        end
+        messages = output.lstrip.split("\n")
       end
 
       unless messages.empty?
diff --git a/lib/overcommit/hook/pre_commit/php_lint.rb b/lib/overcommit/hook/pre_commit/php_lint.rb
index f2ba2f24..9a44e954 100644
--- a/lib/overcommit/hook/pre_commit/php_lint.rb
+++ b/lib/overcommit/hook/pre_commit/php_lint.rb
@@ -21,19 +21,14 @@ def run
         result = execute(command, args: [file])
         output = result.stdout.chomp
         exit_status_sum += result.status
-        if result.status
-          # `php -l` returns with a leading newline, and we only need the first
-          # line, there is usually some redundancy
-          messages << output.lstrip.split("\n").first
-        end
+        # `php -l` returns with a leading newline, and we only need the first
+        # line, there is usually some redundancy
+        messages << output.lstrip.split("\n").first
       end
 
       # If the sum of all lint status is zero, then none had exit status
       return :pass if exit_status_sum == 0
 
-      # No messages is great news for us
-      return :pass if messages.empty?
-
       # Return the list of message objects
       extract_messages(
         messages,
diff --git a/lib/overcommit/hook_context/pre_push.rb b/lib/overcommit/hook_context/pre_push.rb
index 39ec19ba..f5dc1d6f 100644
--- a/lib/overcommit/hook_context/pre_push.rb
+++ b/lib/overcommit/hook_context/pre_push.rb
@@ -79,7 +79,7 @@ def overwritten_commits
 
         result = Overcommit::Subprocess.spawn(%W[git rev-list #{remote_sha1} ^#{local_sha1}])
         if result.success?
-          result.stdout.split("\n")
+          @overwritten_commits = result.stdout.split("\n")
         else
           raise Overcommit::Exceptions::GitRevListError,
                 "Unable to check if commits on the remote ref will be overwritten: #{result.stderr}"
diff --git a/lib/overcommit/installer.rb b/lib/overcommit/installer.rb
index 79287b30..f9966692 100644
--- a/lib/overcommit/installer.rb
+++ b/lib/overcommit/installer.rb
@@ -129,8 +129,6 @@ def can_replace_file?(file)
     end
 
     def preserve_old_hooks
-      return unless File.directory?(hooks_path)
-
       ensure_directory(old_hooks_path)
       Overcommit::Utils.supported_hook_types.each do |hook_type|
         hook_file = File.join(hooks_path, hook_type)
diff --git a/lib/overcommit/utils/messages_utils.rb b/lib/overcommit/utils/messages_utils.rb
index b83d3ac0..86562f96 100644
--- a/lib/overcommit/utils/messages_utils.rb
+++ b/lib/overcommit/utils/messages_utils.rb
@@ -65,8 +65,6 @@ def extract_file(match, message)
       end
 
       def extract_line(match, message)
-        return unless match.names.include?('line')
-
         Integer(match[:line])
       rescue ArgumentError, TypeError
         raise Overcommit::Exceptions::MessageProcessingError,
diff --git a/script/check_coverage.rb b/script/check_coverage.rb
index ced30509..ba0c053a 100644
--- a/script/check_coverage.rb
+++ b/script/check_coverage.rb
@@ -1,9 +1,11 @@
 # frozen_string_literal: true
 
-# Merge LCOV line hits across platforms and shards before enforcing coverage.
+# Merge LCOV hits across Ruby versions, platforms, and shards before enforcing coverage.
 # Individual shards need not cover every line, and platform-specific lines may
 # only run on one operating system.
+require_branches = ARGV.delete('--branches')
 lines = Hash.new(0)
+branches = Hash.new(0)
 ARGV.each do |path|
   source = nil
   File.foreach(path) do |record|
@@ -13,6 +15,10 @@
     when /^DA:(\d+),(\d+)/
       abort "Line coverage without a source file in #{path}" unless source
       lines[[source, Regexp.last_match(1).to_i]] += Regexp.last_match(2).to_i
+    when /^BRDA:(\d+),(\d+),(\d+),(-|\d+)/
+      abort "Branch coverage without a source file in #{path}" unless source
+      line, block, branch, hits = Regexp.last_match.captures
+      branches[[source, line.to_i, block.to_i, branch.to_i]] += hits == '-' ? 0 : hits.to_i
     when /^end_of_record/
       source = nil
     end
@@ -26,3 +32,16 @@
   abort '100% line coverage is required'
 end
 puts "Line coverage: 100% (#{lines.size}/#{lines.size})"
+
+if require_branches
+  abort 'No branch coverage found' if branches.empty?
+
+  uncovered_branches = branches.select { |_, hits| hits == 0 }.keys
+  unless uncovered_branches.empty?
+    warn "Uncovered branches:\n#{uncovered_branches.sort.map do |file, line, block, branch|
+      "#{file}:#{line} (block #{block}, branch #{branch})"
+    end.join("\n")}"
+    abort '100% branch coverage is required'
+  end
+  puts "Branch coverage: 100% (#{branches.size}/#{branches.size})"
+end
diff --git a/spec/coverage_check_spec.rb b/spec/coverage_check_spec.rb
index a2bf506a..43dd4181 100644
--- a/spec/coverage_check_spec.rb
+++ b/spec/coverage_check_spec.rb
@@ -59,3 +59,72 @@ def check_coverage(*reports)
     result.status.should_not == 0
   end
 end
+
+describe 'combined branch coverage check' do
+  let(:script) { File.expand_path('../script/check_coverage.rb', __dir__) }
+
+  def check_branches(*reports)
+    result = nil
+    directory do
+      paths = reports.each_with_index.map do |report, index|
+        path = "coverage-#{index}.info"
+        File.write(path, report)
+        path
+      end
+      result = shell([Gem.ruby, script, '--branches'] + paths)
+    end
+    result
+  end
+
+  it 'combines complementary branch hits across platforms and shards' do
+    result = check_branches(
+      "SF:a.rb\nDA:1,1\nBRDA:1,0,0,1\nBRDA:1,0,1,-\nend_of_record\n",
+      "SF:a.rb\nDA:1,0\nBRDA:1,0,0,0\nBRDA:1,0,1,2\nend_of_record\n",
+    )
+    expect(result.status).to eq(0)
+    expect(result.stdout).to include('Line coverage: 100% (1/1)', 'Branch coverage: 100% (2/2)')
+  end
+
+  ['0', '-'].each do |hits|
+    it "fails for an uncovered branch recorded as #{hits.inspect}" do
+      result = check_branches("SF:a.rb\nDA:1,1\nBRDA:1,0,0,99999\nBRDA:1,0,1,#{hits}\n")
+      expect(result.status).not_to eq(0)
+      expect(result.stderr).to include('a.rb:1 (block 0, branch 1)',
+                                       '100% branch coverage is required')
+    end
+  end
+
+  it 'keeps files, lines, blocks, and branch identities separate' do
+    reports = [
+      "SF:a.rb\nDA:1,1\nBRDA:1,0,0,1\nBRDA:1,0,1,1\nBRDA:1,1,0,1\nBRDA:2,0,0,1\n",
+      "SF:b.rb\nDA:1,1\nBRDA:1,0,0,0\n",
+    ]
+    result = check_branches(*reports)
+    expect(result.status).not_to eq(0)
+    expect(result.stderr).to include('b.rb:1 (block 0, branch 0)')
+  end
+
+  it 'requires branch records when enforcing branch coverage' do
+    result = check_branches("SF:a.rb\nDA:1,1\nend_of_record\n")
+    expect(result.status).not_to eq(0)
+    expect(result.stderr).to include('No branch coverage found')
+  end
+
+  it 'rejects branch records without a source file' do
+    result = check_branches("BRDA:1,0,0,1\n")
+    expect(result.status).not_to eq(0)
+    expect(result.stderr).to include('Branch coverage without a source file')
+  end
+
+  it 'resets the branch source at the end of each record' do
+    result = check_branches("SF:a.rb\nDA:1,1\nend_of_record\nBRDA:1,0,0,1\n")
+    expect(result.status).not_to eq(0)
+    expect(result.stderr).to include('Branch coverage without a source file')
+  end
+
+  it 'continues enforcing line coverage when every branch is covered' do
+    result = check_branches("SF:a.rb\nDA:1,0\nBRDA:1,0,0,1\n")
+    expect(result.status).not_to eq(0)
+    expect(result.stderr).to include('100% line coverage is required')
+  end
+end
diff --git a/spec/overcommit/cli_errors_spec.rb b/spec/overcommit/cli_errors_spec.rb
index e5107103..dfb4cf3d 100644
--- a/spec/overcommit/cli_errors_spec.rb
+++ b/spec/overcommit/cli_errors_spec.rb
@@ -91,4 +91,27 @@
     expect { cli.run }.to raise_error(SystemExit)
     expect(output.string).to include('Example: enabled (plugin)', 'Other: disabled')
   end
+
+  it 'runs an explicitly selected hook context' do
+    arguments.concat(['--run', 'pre-push'])
+    config = double('config', apply_environment!: nil)
+    context = double('context')
+    allow(cli).to receive(:config).and_return(config)
+    expect(Overcommit::HookContext).to receive(:create).
+      with('pre-push', config, [], an_instance_of(File)).and_return(context)
+    allow(Overcommit::Printer).to receive(:new).and_return(double('printer'))
+    allow(Overcommit::HookRunner).to receive(:new).and_return(double(run: true))
+    expect { cli.run }.to raise_error(SystemExit) { |error| expect(error.status).to eq(0) }
+  end
+
+  it 'exits successfully after diff hooks pass' do
+    arguments << '--diff'
+    config = double('config', apply_environment!: nil)
+    context = double('context')
+    allow(cli).to receive(:config).and_return(config)
+    allow(Overcommit::HookContext).to receive(:create).and_return(context)
+    allow(Overcommit::Printer).to receive(:new).and_return(double('printer'))
+    allow(Overcommit::HookRunner).to receive(:new).and_return(double(run: true))
+    expect { cli.run }.to raise_error(SystemExit) { |error| expect(error.status).to eq(0) }
+  end
 end
diff --git a/spec/overcommit/configuration_validator_spec.rb b/spec/overcommit/configuration_validator_spec.rb
index d6b04da5..d5869e76 100644
--- a/spec/overcommit/configuration_validator_spec.rb
+++ b/spec/overcommit/configuration_validator_spec.rb
@@ -124,4 +124,15 @@
       end
     end
   end
+
+  context 'when processor counts are invalid and no logger is supplied' do
+    let(:options) { {} }
+    let(:config_hash) do
+      { 'concurrency' => 1, 'PreCommit' => { 'Example' => { 'processors' => 2 } } }
+    end
+
+    it 'still raises a configuration error' do
+      expect { subject }.to raise_error(Overcommit::Exceptions::ConfigurationError, /processor/)
+    end
+  end
 end
diff --git a/spec/overcommit/gem_plugin_spec.rb b/spec/overcommit/gem_plugin_spec.rb
index 89fe970b..15b2a358 100644
--- a/spec/overcommit/gem_plugin_spec.rb
+++ b/spec/overcommit/gem_plugin_spec.rb
@@ -253,4 +253,10 @@ def changed_config(hash)
                                                 /Unable to activate company-hooks/)
     end
   end
+
+  it 'does not sign Overcommit itself as a plugin dependency' do
+    specification.add_runtime_dependency('overcommit')
+    expect(Gem::Specification).not_to receive(:find_by_name).with('overcommit', anything)
+    expect { plugin.update_signature! }.not_to raise_error
+  end
 end
diff --git a/spec/overcommit/git_config_spec.rb b/spec/overcommit/git_config_spec.rb
index 00eea50d..62ba5d43 100644
--- a/spec/overcommit/git_config_spec.rb
+++ b/spec/overcommit/git_config_spec.rb
@@ -237,4 +237,13 @@
       it { should == '--worktree' }
     end
   end
+
+  it 'resolves commit cleanup mode when no logger is configured' do
+    repo do
+      shell(%w[git config commit.cleanup strip])
+      allow(Overcommit::Utils).to receive(:parent_command).and_return('git commit')
+      allow(Overcommit::Utils).to receive(:log).and_return(nil)
+      expect(described_class.commit_cleanup_mode).to eq('strip')
+    end
+  end
 end
diff --git a/spec/overcommit/git_repo_spec.rb b/spec/overcommit/git_repo_spec.rb
index 90aab79f..56dee1f2 100644
--- a/spec/overcommit/git_repo_spec.rb
+++ b/spec/overcommit/git_repo_spec.rb
@@ -595,4 +595,56 @@ def stage_files(paths)
       it { should be_empty }
     end
   end
+
+  describe 'restoring absent operation state' do
+    around do |example|
+      repo do
+        %w[merge_head merge_mode merge_msg cherry_head].each do |name|
+          described_class.instance_variable_set(:"@#{name}", nil)
+        end
+        example.run
+      ensure
+        %w[merge_head merge_mode merge_msg cherry_head].each do |name|
+          described_class.instance_variable_set(:"@#{name}", nil)
+        end
+      end
+    end
+
+    it 'leaves a repository without merge or cherry-pick state unchanged' do
+      described_class.store_merge_state
+      described_class.store_cherry_pick_state
+      described_class.restore_merge_state
+      described_class.restore_cherry_pick_state
+      %w[MERGE_HEAD MERGE_MODE MERGE_MSG CHERRY_PICK_HEAD].each do |name|
+        expect(File.exist?(Overcommit::Utils.git_path(name))).to eq(false)
+      end
+    end
+
+    it 'restores a merge head without requiring a merge mode or message' do
+      File.write(Overcommit::Utils.git_path('MERGE_HEAD'), 'a' * 40)
+      described_class.store_merge_state
+      FileUtils.rm(Overcommit::Utils.git_path('MERGE_HEAD'))
+      described_class.restore_merge_state
+      expect(File.read(Overcommit::Utils.git_path('MERGE_HEAD'))).to eq('a' * 40)
+      expect(File.exist?(Overcommit::Utils.git_path('MERGE_MODE'))).to eq(false)
+    end
+
+    it 'has no staged submodule removals without a gitmodules file' do
+      expect(described_class.staged_submodule_removals).to eq([])
+    end
+  end
+
+  it 'includes existing submodules when using Git older than 1.8.5' do
+    stub_const('Overcommit::GitRepo::GIT_VERSION', Overcommit::Utils::Version.new('1.8.4'))
+    allow(described_class).to receive(:`).and_return(<<~INI)
+      [submodule "example"]
+        path = example
+        url = https://example.com/example.git
+    INI
+    expect(Overcommit::Utils).to receive(:execute).with(%w[git submodule status example]).
+      and_return(double(success?: true))
+    expect(described_class.submodules).to eq([
+      described_class::Submodule.new('example', 'https://example.com/example.git')
+])
+  end
 end
diff --git a/spec/overcommit/hook/post_commit/git_guilt_spec.rb b/spec/overcommit/hook/post_commit/git_guilt_spec.rb
index d099b507..e7de093a 100644
--- a/spec/overcommit/hook/post_commit/git_guilt_spec.rb
+++ b/spec/overcommit/hook/post_commit/git_guilt_spec.rb
@@ -49,4 +49,11 @@
 
     it { should pass }
   end
+
+  it 'colorizes blame changes when output is a terminal' do
+    allow($stdout).to receive(:tty?).and_return(true)
+    allow(subject).to receive(:initial_commit?).and_return(false)
+    allow(subject).to receive(:execute).and_return(double(success?: true, stdout: 'Tester +++'))
+    expect(subject.run).to eq([:warn, "Tester \e[32m+++\e[0m\e[31m\e[0m"])
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/bundle_check_spec.rb b/spec/overcommit/hook/pre_commit/bundle_check_spec.rb
index b8a471a1..b35c8ba0 100644
--- a/spec/overcommit/hook/pre_commit/bundle_check_spec.rb
+++ b/spec/overcommit/hook/pre_commit/bundle_check_spec.rb
@@ -60,4 +60,14 @@
       end
     end
   end
+
+  it 'preserves an existing lockfile when bundle check does not change it' do
+    repo do
+      File.write('Gemfile.lock', 'locked dependencies')
+      allow(subject).to receive(:execute).with(%w[git ls-files -o -i --exclude-standard]).
+        and_return(double(stdout: ''))
+      allow(subject).to receive(:execute).with(subject.command).and_return(double(success?: true))
+      expect(subject.run).to eq(:pass)
+    end
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/case_conflicts_spec.rb b/spec/overcommit/hook/pre_commit/case_conflicts_spec.rb
index 1ce157d5..cdd1bba6 100644
--- a/spec/overcommit/hook/pre_commit/case_conflicts_spec.rb
+++ b/spec/overcommit/hook/pre_commit/case_conflicts_spec.rb
@@ -35,4 +35,11 @@
 
     it { should pass }
   end
+
+  it 'checks only new files on the initial commit' do
+    allow(Overcommit::GitRepo).to receive(:initial_commit?).and_return(true)
+    allow(subject).to receive(:applicable_files).and_return(%w[foo Foo])
+    expect(Overcommit::GitRepo).not_to receive(:list_files)
+    expect(subject.run.map(&:file)).to include('foo', 'Foo')
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/chamber_verification_spec.rb b/spec/overcommit/hook/pre_commit/chamber_verification_spec.rb
index a49e2a98..042f0b4e 100644
--- a/spec/overcommit/hook/pre_commit/chamber_verification_spec.rb
+++ b/spec/overcommit/hook/pre_commit/chamber_verification_spec.rb
@@ -54,4 +54,16 @@
 
     it { should warn }
   end
+
+  context 'with an approver email configured' do
+    before do
+      allow(subject).to receive(:config).and_return(subject.config.dup)
+      subject.config['approver_email'] = 'approver@example.com'
+      allow(subject).to receive(:execute).and_return(
+        double(stdout: 'Signature mismatch', stderr: '')
+      )
+    end
+
+    it { should warn /your approver \(approver@example.com\)/ }
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/dogma_spec.rb b/spec/overcommit/hook/pre_commit/dogma_spec.rb
index 53b5cd62..5fcf41ef 100644
--- a/spec/overcommit/hook/pre_commit/dogma_spec.rb
+++ b/spec/overcommit/hook/pre_commit/dogma_spec.rb
@@ -48,4 +48,11 @@
       it { should fail_hook }
     end
   end
+
+  it 'returns no messages when unsuccessful output has no file groups' do
+    allow(subject).to receive(:execute).and_return(
+      double(success?: false, stdout: 'No matching files')
+    )
+    expect(subject.run).to eq([])
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/execute_permissions_spec.rb b/spec/overcommit/hook/pre_commit/execute_permissions_spec.rb
index 3e33b946..11901397 100644
--- a/spec/overcommit/hook/pre_commit/execute_permissions_spec.rb
+++ b/spec/overcommit/hook/pre_commit/execute_permissions_spec.rb
@@ -67,4 +67,19 @@ def make_executable_and_add(file, exec_bit)
 
     it_behaves_like 'a file permission hook'
   end
+
+  it 'raises when the Git tree cannot be read' do
+    allow(context).to receive(:initial_commit?).and_return(false)
+    allow(subject).to receive(:execute).with(%w[git ls-tree HEAD --], args: [staged_file]).
+      and_return(double(success?: false))
+    expect { subject.run }.to raise_error(RuntimeError, 'Unable to access git tree')
+  end
+
+  it 'raises when the Git index cannot be read' do
+    allow(context).to receive(:initial_commit?).and_return(true)
+    allow(subject).to receive(:execute).
+      with(%w[git diff --raw --cached --no-color --], args: [staged_file]).
+      and_return(double(success?: false))
+    expect { subject.run }.to raise_error(RuntimeError, 'Unable to access git index')
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/flay_spec.rb b/spec/overcommit/hook/pre_commit/flay_spec.rb
index 2af339bc..f5576252 100644
--- a/spec/overcommit/hook/pre_commit/flay_spec.rb
+++ b/spec/overcommit/hook/pre_commit/flay_spec.rb
@@ -69,4 +69,21 @@
 
     it { should fail_hook }
   end
+
+  context 'when liberal matching is enabled' do
+    let(:result) { double(success?: true, stdout: 'Total score = 0') }
+    let(:config) do
+      default = Overcommit::ConfigurationLoader.default_configuration
+      allow(default).to receive(:for_hook).and_return(
+        default.for_hook('Flay', 'PreCommit').merge('liberal' => true)
+      )
+      default
+    end
+
+    it 'passes the liberal flag to flay' do
+      expect(subject).to receive(:execute).
+        with(%w[flay --mass 16 --fuzzy 1 --liberal], args: applicable_files).and_return(result)
+      expect(subject.run).to eq([])
+    end
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/foodcritic_spec.rb b/spec/overcommit/hook/pre_commit/foodcritic_spec.rb
index 2bbe3df2..74349ba8 100644
--- a/spec/overcommit/hook/pre_commit/foodcritic_spec.rb
+++ b/spec/overcommit/hook/pre_commit/foodcritic_spec.rb
@@ -123,4 +123,22 @@
       end
     end
   end
+
+  context 'with an absolute cookbook directory' do
+    let(:config) { Overcommit::ConfigurationLoader.default_configuration }
+    let(:applicable_files) { [] }
+
+    it 'uses absolute cookbook paths without joining them to the repository root' do
+      cookbook_directory = File.expand_path('cookbooks')
+      allow(subject).to receive(:config).and_return(
+        subject.config.merge('cookbooks_directory' => cookbook_directory)
+      )
+      files = ["#{cookbook_directory}/example/recipe.rb"]
+      allow(subject).to receive(:applicable_files).and_return(files)
+      expect(subject).to receive(:execute).
+        with(subject.command, args: ['-B', "#{cookbook_directory}/example"]).
+        and_return(double(success?: true))
+      expect(subject.run).to eq(:pass)
+    end
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/herb_lint_spec.rb b/spec/overcommit/hook/pre_commit/herb_lint_spec.rb
index f8e13001..cb39facf 100644
--- a/spec/overcommit/hook/pre_commit/herb_lint_spec.rb
+++ b/spec/overcommit/hook/pre_commit/herb_lint_spec.rb
@@ -91,4 +91,19 @@
       it { should fail_hook }
     end
   end
+
+  it 'reports warning offenses with their location and rule' do
+    offense = {
+      'severity' => 'warning', 'filename' => 'view.html.erb',
+      'location' => { 'start' => { 'line' => 3 } },
+      'message' => 'Use a local variable', 'code' => 'no-instance-variables',
+    }
+    allow(subject).to receive(:execute).and_return(
+      double(success?: false, stdout: JSON.generate('offenses' => [offense]))
+    )
+    message = subject.run.fetch(0)
+    expect([message.type, message.file, message.line, message.content]).to eq(
+      [:warning, 'view.html.erb', 3, 'view.html.erb:3 no-instance-variables Use a local variable']
+    )
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/jscs_spec.rb b/spec/overcommit/hook/pre_commit/jscs_spec.rb
index 4cc56dec..d6aba123 100644
--- a/spec/overcommit/hook/pre_commit/jscs_spec.rb
+++ b/spec/overcommit/hook/pre_commit/jscs_spec.rb
@@ -42,4 +42,9 @@
       it { should fail_hook }
     end
   end
+
+  it 'passes when jscs succeeds' do
+    allow(subject).to receive(:execute).and_return(double(success?: true))
+    expect(subject.run).to eq(:pass)
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/line_endings_spec.rb b/spec/overcommit/hook/pre_commit/line_endings_spec.rb
index 78dbfdea..4d714ac7 100644
--- a/spec/overcommit/hook/pre_commit/line_endings_spec.rb
+++ b/spec/overcommit/hook/pre_commit/line_endings_spec.rb
@@ -75,4 +75,25 @@
 
     it { should warn }
   end
+
+  context 'when Git cannot list line endings' do
+    let(:contents) { "text\n" }
+
+    it 'raises rather than silently skipping files' do
+      allow(subject).to receive(:execute).and_return(double(success?: false))
+      expect { subject.run }.to raise_error(RuntimeError, 'Unable to access git tree')
+    end
+  end
+
+  context 'when Git reports matching or binary line endings' do
+    let(:contents) { "text\n" }
+
+    ['l/-text', 'l/lf'].each do |index_info|
+      it "ignores #{index_info} entries" do
+        output = "#{index_info} w/lf attr/\t#{staged_file}\0"
+        allow(subject).to receive(:execute).and_return(double(success?: true, stdout: output))
+        expect(subject.run).to eq([])
+      end
+    end
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/phpcs_fixer_spec.rb b/spec/overcommit/hook/pre_commit/phpcs_fixer_spec.rb
index a4b1e187..1e97f4c4 100644
--- a/spec/overcommit/hook/pre_commit/phpcs_fixer_spec.rb
+++ b/spec/overcommit/hook/pre_commit/phpcs_fixer_spec.rb
@@ -83,4 +83,9 @@
     end
     it { should fail_hook }
   end
+
+  it 'returns no feedback when no files need processing' do
+    allow(subject).to receive(:applicable_files).and_return([])
+    expect(subject.run).to eq('')
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/phpcs_spec.rb b/spec/overcommit/hook/pre_commit/phpcs_spec.rb
index 6982a297..318ae7d2 100644
--- a/spec/overcommit/hook/pre_commit/phpcs_spec.rb
+++ b/spec/overcommit/hook/pre_commit/phpcs_spec.rb
@@ -65,4 +65,16 @@
       it { should fail_hook }
     end
   end
+
+  it 'fails when phpcs fails without reporting any offenses' do
+    allow(subject).to receive(:execute).and_return(
+      double(status: 1, success?: false, stdout: '')
+    )
+    expect(subject.run).to eq(:fail)
+  end
+
+  it 'fails when phpcs terminates without an exit status' do
+    allow(subject).to receive(:execute).and_return(double(status: nil, success?: false))
+    expect(subject.run).to eq(:fail)
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/ruby_syntax_spec.rb b/spec/overcommit/hook/pre_commit/ruby_syntax_spec.rb
index 0eaa4459..eebe2eec 100644
--- a/spec/overcommit/hook/pre_commit/ruby_syntax_spec.rb
+++ b/spec/overcommit/hook/pre_commit/ruby_syntax_spec.rb
@@ -46,4 +46,12 @@
       it { should fail_hook }
     end
   end
+
+  it 'reports Ruby warnings without promoting them to errors' do
+    allow(subject).to receive(:execute).and_return(
+      double(stderr: 'file.rb:3: warning: assigned but unused variable, unused')
+    )
+    message = subject.run.fetch(0)
+    expect([message.type, message.file, message.line]).to eq([:warning, 'file.rb', 3])
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/scss_lint_spec.rb b/spec/overcommit/hook/pre_commit/scss_lint_spec.rb
index ae8b2f68..10466564 100644
--- a/spec/overcommit/hook/pre_commit/scss_lint_spec.rb
+++ b/spec/overcommit/hook/pre_commit/scss_lint_spec.rb
@@ -94,4 +94,18 @@
       it { should pass }
     end
   end
+
+  it 'reports command failures with both output streams' do
+    allow(subject).to receive(:execute).and_return(
+      double(status: 64, stdout: 'Usage: scss-lint', stderr: 'Invalid option')
+    )
+    expect(subject.run).to eq([:fail, 'Usage: scss-lintInvalid option'])
+  end
+
+  it 'reports a syntax error without a linter name' do
+    output = { 'test.scss' => [{ 'line' => 2, 'severity' => 'error', 'reason' => 'Syntax error' }] }
+    allow(subject).to receive(:execute).and_return(double(status: 2, stdout: JSON.generate(output)))
+    message = subject.run.fetch(0)
+    expect([message.type, message.content]).to eq([:error, 'test.scss:2 Syntax error'])
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/w3c_css_spec.rb b/spec/overcommit/hook/pre_commit/w3c_css_spec.rb
index 9ec45800..aac8e642 100644
--- a/spec/overcommit/hook/pre_commit/w3c_css_spec.rb
+++ b/spec/overcommit/hook/pre_commit/w3c_css_spec.rb
@@ -75,4 +75,16 @@
       it { should fail_hook }
     end
   end
+
+  it 'uses validator defaults when optional settings are nil' do
+    allow(subject).to receive(:config).and_return(subject.config.dup)
+    subject.config['language'] = nil
+    subject.config['profile'] = nil
+    subject.config['warn_level'] = nil
+    validator = double('validator', validate_file: double(errors: [], warnings: []))
+    factory = double('validator class', new: validator)
+    stub_const('W3CValidators::CSSValidator', factory)
+    expect(validator).not_to receive(:set_language!)
+    expect(subject.run).to eq([])
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/w3c_html_spec.rb b/spec/overcommit/hook/pre_commit/w3c_html_spec.rb
index e517bb34..b524a541 100644
--- a/spec/overcommit/hook/pre_commit/w3c_html_spec.rb
+++ b/spec/overcommit/hook/pre_commit/w3c_html_spec.rb
@@ -75,4 +75,15 @@
       it { should fail_hook }
     end
   end
+
+  it 'uses validator defaults when optional settings are nil' do
+    allow(subject).to receive(:config).and_return(subject.config.dup)
+    subject.config['charset'] = nil
+    subject.config['doctype'] = nil
+    validator = double('validator', validate_file: double(errors: [], warnings: []))
+    factory = double('validator class', new: validator)
+    stub_const('W3CValidators::MarkupValidator', factory)
+    expect(validator).to receive(:set_debug!)
+    expect(subject.run).to eq([])
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/yard_coverage_spec.rb b/spec/overcommit/hook/pre_commit/yard_coverage_spec.rb
index d463d25d..b4e56ab8 100644
--- a/spec/overcommit/hook/pre_commit/yard_coverage_spec.rb
+++ b/spec/overcommit/hook/pre_commit/yard_coverage_spec.rb
@@ -96,4 +96,17 @@
       it { should fail_hook }
     end
   end
+
+  it 'reports undocumented objects even when no minimum percentage is configured' do
+    allow(subject).to receive(:config).and_return(
+      subject.config.merge('min_coverage_percentage' => nil)
+    )
+    output = (['Stats'] * 6 + ['50% documented', 'Undocumented Objects:', 'Example (file.rb:2)']).
+      join("\n")
+    allow(subject).to receive(:execute).and_return(double(stdout: output))
+    messages = subject.run
+    expect(messages.last.file).to eq('file.rb')
+    expect(messages.last.line).to eq('2')
+    expect(messages.last.type).to eq(:error)
+  end
 end
diff --git a/spec/overcommit/hook/pre_commit/yarn_check_spec.rb b/spec/overcommit/hook/pre_commit/yarn_check_spec.rb
index f67fa9b2..b25380b4 100644
--- a/spec/overcommit/hook/pre_commit/yarn_check_spec.rb
+++ b/spec/overcommit/hook/pre_commit/yarn_check_spec.rb
@@ -86,4 +86,15 @@
       it { should fail_hook }
     end
   end
+
+  it 'preserves an existing lockfile when yarn does not change it' do
+    repo do
+      File.write('yarn.lock', 'locked dependencies')
+      allow(subject).to receive(:execute).with(%w[git ls-files -o -i --exclude-standard]).
+        and_return(double(stdout: ''))
+      allow(subject).to receive(:execute).with(subject.command).and_return(double(stderr: ''))
+      expect(subject.run).to eq(:pass)
+      expect(File.read('yarn.lock')).to eq('locked dependencies')
+    end
+  end
 end
diff --git a/spec/overcommit/hook/prepare_commit_msg/base_spec.rb b/spec/overcommit/hook/prepare_commit_msg/base_spec.rb
index 85b6452b..09c0a22a 100644
--- a/spec/overcommit/hook/prepare_commit_msg/base_spec.rb
+++ b/spec/overcommit/hook/prepare_commit_msg/base_spec.rb
@@ -48,4 +48,10 @@
       expect(File.read(tempfile)).to match(/alpha\n#{initial_content}bravo\n/m)
     end
   end
+
+  it 'requires a block before modifying a commit message' do
+    expect do
+      described_class.new(config, context).modify_commit_message
+    end.to raise_error(RuntimeError, 'This expects a block!')
+  end
 end
diff --git a/spec/overcommit/hook/prepare_commit_msg/replace_branch_spec.rb b/spec/overcommit/hook/prepare_commit_msg/replace_branch_spec.rb
index 3e7332c5..10c48bc7 100644
--- a/spec/overcommit/hook/prepare_commit_msg/replace_branch_spec.rb
+++ b/spec/overcommit/hook/prepare_commit_msg/replace_branch_spec.rb
@@ -335,4 +335,14 @@ def remove_file(name)
       end
     end
   end
+
+  it 'recognizes an exact prefix that ends in a word character' do
+    allow(hook).to receive(:new_template).and_return('PROJ-12 ')
+    expect(hook.keep_message?('PROJ-12')).to eq(true)
+  end
+
+  it 'uses the default pattern when the configured pattern is absent' do
+    allow(hook).to receive(:config).and_return(hook.config.merge('branch_pattern' => nil))
+    expect(hook.branch_pattern).to eq(described_class::DEFAULT_BRANCH_PATTERN)
+  end
 end
diff --git a/spec/overcommit/hook_context/base_spec.rb b/spec/overcommit/hook_context/base_spec.rb
index ecae943b..bfe0c4f6 100644
--- a/spec/overcommit/hook_context/base_spec.rb
+++ b/spec/overcommit/hook_context/base_spec.rb
@@ -82,4 +82,11 @@ def finish_reading
 
     it { should be_nil }
   end
+
+  it 'reads input only once across repeated calls' do
+    input = double('input')
+    expect(input).to receive(:read).once.and_return('hook input')
+    context = described_class.new(nil, [], input)
+    2.times { expect(context.input_string).to eq('hook input') }
+  end
 end
diff --git a/spec/overcommit/hook_context/helpers/hide_unstaged_changes_spec.rb b/spec/overcommit/hook_context/helpers/hide_unstaged_changes_spec.rb
index a173c5c6..c7e9e640 100644
--- a/spec/overcommit/hook_context/helpers/hide_unstaged_changes_spec.rb
+++ b/spec/overcommit/hook_context/helpers/hide_unstaged_changes_spec.rb
@@ -444,3 +444,15 @@ def patches
     end
   end
 end
+
+describe Overcommit::HookContext::PreCommit, 'timestamp collection' do
+  it 'ignores missing files while storing modification times' do
+    repo do
+      context = described_class.new(nil, [], nil)
+      allow(context).to receive(:modified_files).and_return(['missing.rb'])
+      allow(Overcommit::GitRepo).to receive(:modified_files).with(staged: false).and_return([])
+      expect(File).not_to receive(:mtime)
+      expect { context.send(:store_modified_times) }.not_to raise_error
+    end
+  end
+end
diff --git a/spec/overcommit/hook_context/post_commit_spec.rb b/spec/overcommit/hook_context/post_commit_spec.rb
index 81758256..7d81ac32 100644
--- a/spec/overcommit/hook_context/post_commit_spec.rb
+++ b/spec/overcommit/hook_context/post_commit_spec.rb
@@ -143,4 +143,10 @@
       it { should == true }
     end
   end
+
+  it 'caches whether this is the initial commit' do
+    expect(Overcommit::Utils).to receive(:execute).once.with(%w[git rev-parse HEAD~]).
+      and_return(double(success?: false))
+    2.times { expect(context.initial_commit?).to eq(true) }
+  end
 end
diff --git a/spec/overcommit/hook_context/pre_commit_spec.rb b/spec/overcommit/hook_context/pre_commit_spec.rb
index 7f1f6abb..02b3af53 100644
--- a/spec/overcommit/hook_context/pre_commit_spec.rb
+++ b/spec/overcommit/hook_context/pre_commit_spec.rb
@@ -663,4 +663,20 @@
       it { should == Set.new(1..4) }
     end
   end
+
+  it 'does not infer an amendment when the parent process is unavailable' do
+    allow(Overcommit::Utils).to receive(:parent_command).and_return(nil)
+    expect(context.amendment?).to be_nil
+  end
+
+  it 'reuses the modified file list and modified lines within one run' do
+    allow(context).to receive(:amendment?).and_return(false)
+    expect(Overcommit::GitRepo).to receive(:modified_files).once.with(staged: true).and_return([])
+    expect(Overcommit::GitRepo).to receive(:extract_modified_lines).once.
+      with('file.rb', staged: true).and_return(Set[2])
+    2.times do
+      expect(context.modified_files).to eq([])
+      expect(context.modified_lines_in_file('file.rb')).to eq(Set[2])
+    end
+  end
 end
diff --git a/spec/overcommit/hook_context/pre_push_spec.rb b/spec/overcommit/hook_context/pre_push_spec.rb
index 101e0f1a..451960ec 100644
--- a/spec/overcommit/hook_context/pre_push_spec.rb
+++ b/spec/overcommit/hook_context/pre_push_spec.rb
@@ -472,4 +472,17 @@
       end
     end
   end
+
+  it 'caches an empty push as not deleting a remote ref' do
+    expect(input).to receive(:read).once.and_return('')
+    2.times { expect(context.remote_ref_deletion?).to eq(false) }
+  end
+
+  it 'reuses the remote history query when checking a pushed ref repeatedly' do
+    ref = described_class::PushedRef.new('local', 'a' * 40, 'remote', 'b' * 40)
+    expect(Overcommit::Subprocess).to receive(:spawn).once.
+      with(['git', 'rev-list', 'b' * 40, "^#{'a' * 40}"]).
+      and_return(double(success?: true, stdout: "overwritten-commit\n"))
+    2.times { expect(ref.forced?).to eq(true) }
+  end
 end
diff --git a/spec/overcommit/hook_context/pre_rebase_spec.rb b/spec/overcommit/hook_context/pre_rebase_spec.rb
index 58e0e8c2..1e00ff31 100644
--- a/spec/overcommit/hook_context/pre_rebase_spec.rb
+++ b/spec/overcommit/hook_context/pre_rebase_spec.rb
@@ -106,4 +106,11 @@
       it { should_not be_empty }
     end
   end
+
+  it 'lists commits from HEAD when rebasing a detached checkout' do
+    allow(context).to receive(:rebased_branch).and_return('')
+    expect(context).to receive(:`).with('git rev-list --topo-order --reverse master..HEAD').
+      and_return("abc123\n")
+    expect(context.rebased_commits).to eq(['abc123'])
+  end
 end
diff --git a/spec/overcommit/hook_runner_spec.rb b/spec/overcommit/hook_runner_spec.rb
index 95cc0469..251f231a 100644
--- a/spec/overcommit/hook_runner_spec.rb
+++ b/spec/overcommit/hook_runner_spec.rb
@@ -89,4 +89,32 @@
       end.to raise_error(Overcommit::Exceptions::HookLoadError, /forget.*gem.*missing/m)
     end
   end
+
+  it 'does not print recovery instructions when the context provides none' do
+    allow(context).to receive(:post_fail_message).and_return(nil)
+    allow(hook).to receive(:run_and_transform).and_return([:fail, nil])
+    expect(printer).not_to receive(:hook_run_failed)
+    expect(runner.run).to eq(false)
+  end
+
+  it 'does not print an end result after the run has been interrupted' do
+    allow(hook).to receive(:run_and_transform) do
+      runner.instance_variable_set(:@interrupted, true)
+      [:pass, nil]
+    end
+    expect(printer).not_to receive(:end_hook)
+    expect(runner.run).to eq(false)
+  end
+
+  it 'does not announce skipped hooks that would not run anyway' do
+    allow(hook).to receive_messages(skip?: true, run?: false)
+    expect(printer).not_to receive(:hook_skipped)
+    expect(runner.run).to eq(true)
+  end
+
+  it 'does not start another hook after interruption' do
+    runner.instance_variable_set(:@interrupted, true)
+    expect(hook).not_to receive(:run_and_transform)
+    expect(runner.send(:should_skip?, hook)).to eq(true)
+  end
 end
diff --git a/spec/overcommit/hook_signer_files_spec.rb b/spec/overcommit/hook_signer_files_spec.rb
index 36bb0aa4..8876aad2 100644
--- a/spec/overcommit/hook_signer_files_spec.rb
+++ b/spec/overcommit/hook_signer_files_spec.rb
@@ -49,4 +49,9 @@
 
     include_examples 'a signed repository command'
   end
+
+  it 'recognizes a Windows-relative command path' do
+    allow(Overcommit::OS).to receive(:windows?).and_return(true)
+    expect(signer.signable_file?('.\\hook-script')).to eq(true)
+  end
 end
diff --git a/spec/overcommit/installer_spec.rb b/spec/overcommit/installer_spec.rb
index 5283b2b6..ea3db413 100644
--- a/spec/overcommit/installer_spec.rb
+++ b/spec/overcommit/installer_spec.rb
@@ -250,4 +250,20 @@ def hook_files_installed?(hooks_dir)
       end
     end
   end
+
+  it 'installs into a repository whose hooks directory is absent' do
+    repo do
+      FileUtils.rm_rf(Overcommit::GitConfig.hooks_path)
+      installer.run(Dir.pwd, action: :install)
+      expect(hook_files_installed?(Overcommit::GitConfig.hooks_path)).to eq(true)
+    end
+  end
+
+  it 'can uninstall when the hooks directory is already absent' do
+    repo do
+      FileUtils.rm_rf(Overcommit::GitConfig.hooks_path)
+      expect { installer.run(Dir.pwd, action: :uninstall) }.not_to raise_error
+      expect(File.directory?(Overcommit::GitConfig.hooks_path)).to eq(false)
+    end
+  end
 end
diff --git a/spec/overcommit/logger_spec.rb b/spec/overcommit/logger_spec.rb
index 681e0dff..62e506f6 100644
--- a/spec/overcommit/logger_spec.rb
+++ b/spec/overcommit/logger_spec.rb
@@ -180,4 +180,9 @@
       let(:color_code) { '1;33' }
     end
   end
+
+  it 'can flush an output stream that does not implement flush' do
+    logger = described_class.new(double('output', tty?: false))
+    expect { logger.flush }.not_to raise_error
+  end
 end
diff --git a/spec/overcommit/message_processor_spec.rb b/spec/overcommit/message_processor_spec.rb
index f90a1f0f..f640f448 100644
--- a/spec/overcommit/message_processor_spec.rb
+++ b/spec/overcommit/message_processor_spec.rb
@@ -289,4 +289,12 @@ def warning(file = nil, line = nil)
       end
     end
   end
+
+  it 'retains file-wide errors when ignoring unmodified lines' do
+    hook = double('hook', modified_lines_in_file: Set.new)
+    message = Overcommit::Hook::Message.new(:error, 'file.rb', nil, 'File-wide error')
+    processor = described_class.new(hook, 'ignore')
+    expect(hook).not_to receive(:modified_lines_in_file)
+    expect(processor.hook_result([message])).to eq([:fail, "Errors:\nFile-wide error\n"])
+  end
 end
diff --git a/spec/overcommit/printer_spec.rb b/spec/overcommit/printer_spec.rb
index 268157a7..ecc88f6b 100644
--- a/spec/overcommit/printer_spec.rb
+++ b/spec/overcommit/printer_spec.rb
@@ -93,4 +93,10 @@
       printer.end_hook(hook, :fail, 'Details')
     end
   end
+
+  it 'suppresses the run heading in quiet mode' do
+    config['quiet'] = true
+    expect(logger).not_to receive(:bold)
+    printer.start_run
+  end
 end
diff --git a/spec/overcommit/signature_spec.rb b/spec/overcommit/signature_spec.rb
index d051fd2a..7abe5b72 100644
--- a/spec/overcommit/signature_spec.rb
+++ b/spec/overcommit/signature_spec.rb
@@ -209,4 +209,13 @@
     expect { store }.to raise_error(Overcommit::Exceptions::GitConfigError, /cannot lock config/)
     File.read(signature_file).should include(signature)
   end
+
+  it 'tolerates another process removing a legacy signature during migration' do
+    allow(Overcommit::Utils).to receive(:execute).and_call_original
+    allow(Overcommit::Utils).to receive(:execute).with(%w[git config --local --get] + [key]).
+      and_return(Overcommit::Subprocess::Result.new(0, signature, ''))
+    allow(Overcommit::Utils).to receive(:execute).with(%w[git config --local --unset-all] + [key]).
+      and_return(Overcommit::Subprocess::Result.new(5, '', ''))
+    expect(store.include?(signature)).to eq(true)
+  end
 end
diff --git a/spec/overcommit/subprocess_spec.rb b/spec/overcommit/subprocess_spec.rb
index e2e1c698..2b480507 100644
--- a/spec/overcommit/subprocess_spec.rb
+++ b/spec/overcommit/subprocess_spec.rb
@@ -197,4 +197,9 @@ def expect_tempfiles_deleted
       described_class.spawn_detached(args)
     end
   end
+
+  it 'preserves the startup error when no output streams could be assigned' do
+    allow(described_class).to receive(:assign_output_streams).and_raise(IOError, 'No temp space')
+    expect { described_class.spawn([ruby, '-e', '']) }.to raise_error(IOError, 'No temp space')
+  end
 end
diff --git a/spec/overcommit/utils/messages_errors_spec.rb b/spec/overcommit/utils/messages_errors_spec.rb
index c823cf7c..4ef8f81f 100644
--- a/spec/overcommit/utils/messages_errors_spec.rb
+++ b/spec/overcommit/utils/messages_errors_spec.rb
@@ -17,4 +17,10 @@
     expect { described_class.extract_messages(['file'], /(?<file>.*)/, ->(_) { :invalid }) }.
       to raise_error(Overcommit::Exceptions::MessageProcessingError, /Invalid message type/)
   end
+
+  it 'categorizes missing types as errors with a string warning pattern' do
+    categorizer = described_class.create_type_categorizer('warning')
+    messages = described_class.extract_messages(['file.rb'], /(?<file>.*)/, categorizer)
+    expect(messages.first.type).to eq(:error)
+  end
 end
diff --git a/spec/overcommit/utils_errors_spec.rb b/spec/overcommit/utils_errors_spec.rb
index b798f2d2..d35a7c4c 100644
--- a/spec/overcommit/utils_errors_spec.rb
+++ b/spec/overcommit/utils_errors_spec.rb
@@ -41,4 +41,33 @@
       and_return("git commit\n")
     expect(described_class.parent_command).to eq('git commit')
   end
+
+  it 'uses the legacy Git directory command with older Git versions' do
+    stub_const('Overcommit::Utils::GIT_VERSION', described_class::Version.new('2.4'))
+    expect(described_class).to receive(:execute).with(%w[git rev-parse --git-dir]).
+      and_return(double(success?: true, stdout: ".git\n"))
+    expect(described_class.git_dir).to eq(File.expand_path('.git'))
+  end
+
+  it 'tries Windows executable extensions when PATHEXT is set' do
+    allow(described_class).to receive(:repo_root).and_return(Dir.pwd)
+    Overcommit::Utils.with_environment('PATHEXT' => '.EXE;.BAT') do
+      allow(File).to receive(:executable?).and_return(false)
+      expect(File).to receive(:executable?).with(File.join(Dir.pwd, 'tool.EXE')).and_return(true)
+      expect(described_class.in_path?('tool')).to eq(true)
+    end
+  end
+
+  it 'recognizes commands that already have a Windows executable extension' do
+    allow(described_class).to receive(:repo_root).and_return(Dir.pwd)
+    Overcommit::Utils.with_environment('PATHEXT' => '.EXE') do
+      expect(File).to receive(:executable?).with(File.join(Dir.pwd, 'tool.exe')).and_return(true)
+      expect(described_class.in_path?('tool.exe')).to eq(true)
+    end
+  end
+
+  it 'returns no parent command if PowerShell fails' do
+    allow(described_class).to receive(:execute).and_return(double(success?: false, stdout: ''))
+    expect(described_class.send(:powershell_windows_parent_command)).to be_nil
+  end
 end

From f207084677476c23ee85f4c2cf683def1bec5c62 Mon Sep 17 00:00:00 2001
From: Shane da Silva <shane@dasilva.io>
Date: Tue, 10 Nov 2026 22:37:35 -0800
Subject: [PATCH 2/2] Use a portable rooted path in the Foodcritic regression
 test

---
 spec/overcommit/hook/pre_commit/foodcritic_spec.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/spec/overcommit/hook/pre_commit/foodcritic_spec.rb b/spec/overcommit/hook/pre_commit/foodcritic_spec.rb
index 74349ba8..85199960 100644
--- a/spec/overcommit/hook/pre_commit/foodcritic_spec.rb
+++ b/spec/overcommit/hook/pre_commit/foodcritic_spec.rb
@@ -129,7 +129,7 @@
     let(:applicable_files) { [] }
 
     it 'uses absolute cookbook paths without joining them to the repository root' do
-      cookbook_directory = File.expand_path('cookbooks')
+      cookbook_directory = File.join(File::SEPARATOR, 'cookbooks')
       allow(subject).to receive(:config).and_return(
         subject.config.merge('cookbooks_directory' => cookbook_directory)
       )