From d8c3ff89083287b9bd9f46e588e202997ca0ce47 Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Tue, 7 Apr 2015 20:50:05 -0400
Subject: [PATCH 01/18] Add method Utils.parent_command

Returns the name of the command corresponding to the parent of
the current process, which will be the calling git command when
running hooks.
---
 lib/overcommit/utils.rb | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/overcommit/utils.rb b/lib/overcommit/utils.rb
index 540937f3..20bcfaf4 100644
--- a/lib/overcommit/utils.rb
+++ b/lib/overcommit/utils.rb
@@ -101,6 +101,11 @@ def in_path?(cmd)
         false
       end
 
+      # Return the parent command that triggered this hook run
+      def parent_command
+        `ps -ocommand= -p #{Process.ppid}`.chomp
+      end
+
       # Execute a command in a subprocess, capturing exit status and output from
       # both standard and error streams.
       #

From f30dd0cedbb7e9768fb1c74a895318e723a456d9 Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Tue, 7 Apr 2015 20:51:45 -0400
Subject: [PATCH 02/18] Add spec for Utils.parent_command

---
 spec/overcommit/utils_spec.rb | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/spec/overcommit/utils_spec.rb b/spec/overcommit/utils_spec.rb
index 91bb32ef..215a1aee 100644
--- a/spec/overcommit/utils_spec.rb
+++ b/spec/overcommit/utils_spec.rb
@@ -121,6 +121,16 @@
     # rubocop:enable Metrics/LineLength
   end
 
+  describe '.parent_command' do
+    subject { described_class.parent_command }
+
+    before do
+      Process.stub(:ppid) { Process.pid }
+    end
+
+    it { should =~ /rspec/ }
+  end
+
   describe '.execute' do
     let(:arguments) { %w[echo -n Hello World] }
     subject { described_class.execute(arguments) }

From b42eac48db90c85088c99a35c122e8eedc122658 Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Tue, 7 Apr 2015 20:52:08 -0400
Subject: [PATCH 03/18] Add helper method HookContext::PreCommit#amend?

Returns true if the current hook run was initiated by amending
a commit, false otherwise.
---
 lib/overcommit/hook_context/pre_commit.rb | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/lib/overcommit/hook_context/pre_commit.rb b/lib/overcommit/hook_context/pre_commit.rb
index 289eaffe..53d15118 100644
--- a/lib/overcommit/hook_context/pre_commit.rb
+++ b/lib/overcommit/hook_context/pre_commit.rb
@@ -82,6 +82,15 @@ def modified_lines_in_file(file)
         Overcommit::GitRepo.extract_modified_lines(file, staged: true)
     end
 
+    # Returns whether this hook run was triggered by `git commit --amend`
+    def amend?
+      cmd = Overcommit::Utils.last_command
+      amend_alias = `git config --get-regexp '^alias\\.' '--amend'`.
+        slice(/(?<=alias\.)\w+/)
+
+      (/--amend|git #{amend_alias}/ =~ cmd) != nil
+    end
+
     private
 
     # Clears the working tree so that the stash can be applied.

From fdb12303f40fe27941b0dbc15cdd9d8a846a993a Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Tue, 7 Apr 2015 20:53:07 -0400
Subject: [PATCH 04/18] Add specs for HookContext::PreCommit#amend?

---
 .../hook_context/pre_commit_spec.rb           | 35 +++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/spec/overcommit/hook_context/pre_commit_spec.rb b/spec/overcommit/hook_context/pre_commit_spec.rb
index b1af2d0e..e098d44c 100644
--- a/spec/overcommit/hook_context/pre_commit_spec.rb
+++ b/spec/overcommit/hook_context/pre_commit_spec.rb
@@ -7,6 +7,41 @@
   let(:input) { double('input') }
   let(:context) { described_class.new(config, args, input) }
 
+  describe '#amend?' do
+    subject { context.amend? }
+
+    context 'when amending a commit using `git commit --amend`' do
+      before do
+        Overcommit::Utils.stub(:last_command).and_return('git commit --amend')
+      end
+
+      it { should == true }
+    end
+
+    context 'when amending a commit using a git alias' do
+      around do |example|
+        repo do
+          `git config alias.amend 'commit --amend'`
+          example.run
+        end
+      end
+
+      before do
+        Overcommit::Utils.stub(:last_command).and_return('git amend')
+      end
+
+      it { should == true }
+    end
+
+    context 'when not amending a commit' do
+      before do
+        Overcommit::Utils.stub(:last_command).and_return('git commit')
+      end
+
+      it { should == false }
+    end
+  end
+
   describe '#setup_environment' do
     subject { context.setup_environment }
 

From 21b2321fdf1a461cc7655baaabfcfb43f434441f Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Tue, 7 Apr 2015 21:22:31 -0400
Subject: [PATCH 05/18] Use Utils.parent_command, not last_command

---
 lib/overcommit/hook_context/pre_commit.rb       | 2 +-
 spec/overcommit/hook_context/pre_commit_spec.rb | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/overcommit/hook_context/pre_commit.rb b/lib/overcommit/hook_context/pre_commit.rb
index 53d15118..48a6f1fe 100644
--- a/lib/overcommit/hook_context/pre_commit.rb
+++ b/lib/overcommit/hook_context/pre_commit.rb
@@ -84,7 +84,7 @@ def modified_lines_in_file(file)
 
     # Returns whether this hook run was triggered by `git commit --amend`
     def amend?
-      cmd = Overcommit::Utils.last_command
+      cmd = Overcommit::Utils.parent_command
       amend_alias = `git config --get-regexp '^alias\\.' '--amend'`.
         slice(/(?<=alias\.)\w+/)
 
diff --git a/spec/overcommit/hook_context/pre_commit_spec.rb b/spec/overcommit/hook_context/pre_commit_spec.rb
index e098d44c..c63050a9 100644
--- a/spec/overcommit/hook_context/pre_commit_spec.rb
+++ b/spec/overcommit/hook_context/pre_commit_spec.rb
@@ -12,7 +12,7 @@
 
     context 'when amending a commit using `git commit --amend`' do
       before do
-        Overcommit::Utils.stub(:last_command).and_return('git commit --amend')
+        Overcommit::Utils.stub(:parent_command).and_return('git commit --amend')
       end
 
       it { should == true }
@@ -27,7 +27,7 @@
       end
 
       before do
-        Overcommit::Utils.stub(:last_command).and_return('git amend')
+        Overcommit::Utils.stub(:parent_command).and_return('git amend')
       end
 
       it { should == true }
@@ -35,7 +35,7 @@
 
     context 'when not amending a commit' do
       before do
-        Overcommit::Utils.stub(:last_command).and_return('git commit')
+        Overcommit::Utils.stub(:parent_command).and_return('git commit')
       end
 
       it { should == false }

From 55d41cf2edfb826526488b698cdb3051ef7925e4 Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Tue, 7 Apr 2015 21:24:10 -0400
Subject: [PATCH 06/18] Disable ClassLength warning for HookContext::PreCommit

---
 lib/overcommit/hook_context/pre_commit.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/overcommit/hook_context/pre_commit.rb b/lib/overcommit/hook_context/pre_commit.rb
index 48a6f1fe..7fde1476 100644
--- a/lib/overcommit/hook_context/pre_commit.rb
+++ b/lib/overcommit/hook_context/pre_commit.rb
@@ -7,7 +7,7 @@ module Overcommit::HookContext
   # This includes staged files, which lines of those files have been modified,
   # etc. It is also responsible for saving/restoring the state of the repo so
   # hooks only inspect staged changes.
-  class PreCommit < Base
+  class PreCommit < Base # rubocop:disable ClassLength
     # Stash unstaged contents of files so hooks don't see changes that aren't
     # about to be committed.
     def setup_environment

From 4796111d946ea6ee37311e271d11322448ec56c7 Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Tue, 7 Apr 2015 21:26:09 -0400
Subject: [PATCH 07/18] Move HookContext::PreCommit#amend? to top of class

---
 lib/overcommit/hook_context/pre_commit.rb | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/lib/overcommit/hook_context/pre_commit.rb b/lib/overcommit/hook_context/pre_commit.rb
index 7fde1476..50640ed0 100644
--- a/lib/overcommit/hook_context/pre_commit.rb
+++ b/lib/overcommit/hook_context/pre_commit.rb
@@ -8,6 +8,15 @@ module Overcommit::HookContext
   # etc. It is also responsible for saving/restoring the state of the repo so
   # hooks only inspect staged changes.
   class PreCommit < Base # rubocop:disable ClassLength
+    # Returns whether this hook run was triggered by `git commit --amend`
+    def amend?
+      cmd = Overcommit::Utils.parent_command
+      amend_alias = `git config --get-regexp '^alias\\.' '--amend'`.
+        slice(/(?<=alias\.)\w+/)
+
+      (/--amend|git #{amend_alias}/ =~ cmd) != nil
+    end
+
     # Stash unstaged contents of files so hooks don't see changes that aren't
     # about to be committed.
     def setup_environment
@@ -82,15 +91,6 @@ def modified_lines_in_file(file)
         Overcommit::GitRepo.extract_modified_lines(file, staged: true)
     end
 
-    # Returns whether this hook run was triggered by `git commit --amend`
-    def amend?
-      cmd = Overcommit::Utils.parent_command
-      amend_alias = `git config --get-regexp '^alias\\.' '--amend'`.
-        slice(/(?<=alias\.)\w+/)
-
-      (/--amend|git #{amend_alias}/ =~ cmd) != nil
-    end
-
     private
 
     # Clears the working tree so that the stash can be applied.

From 005d67a9132a5a57820d7eab4b9b8bec33da7fc7 Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Tue, 7 Apr 2015 21:27:27 -0400
Subject: [PATCH 08/18] Cache HookContext::PreCommit#amend? value

---
 lib/overcommit/hook_context/pre_commit.rb | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/lib/overcommit/hook_context/pre_commit.rb b/lib/overcommit/hook_context/pre_commit.rb
index 50640ed0..14ad3273 100644
--- a/lib/overcommit/hook_context/pre_commit.rb
+++ b/lib/overcommit/hook_context/pre_commit.rb
@@ -10,11 +10,16 @@ module Overcommit::HookContext
   class PreCommit < Base # rubocop:disable ClassLength
     # Returns whether this hook run was triggered by `git commit --amend`
     def amend?
-      cmd = Overcommit::Utils.parent_command
-      amend_alias = `git config --get-regexp '^alias\\.' '--amend'`.
-        slice(/(?<=alias\.)\w+/)
+      if @amended.nil?
+        cmd = Overcommit::Utils.parent_command
+        @amended = !(/--amend/ =~ cmd).nil?
 
-      (/--amend|git #{amend_alias}/ =~ cmd) != nil
+        amend_alias = `git config --get-regexp '^alias\\.' '--amend'`.
+          slice(/(?<=alias\.)\w+/)
+
+        @amended ||= !(/git #{amend_alias}/ =~ cmd).nil? unless amend_alias.nil?
+      end
+      @amended
     end
 
     # Stash unstaged contents of files so hooks don't see changes that aren't

From 30f45760db05c1a4a02e9fd9f37c8012bfd43c25 Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Tue, 7 Apr 2015 21:28:05 -0400
Subject: [PATCH 09/18] Include modifications from last commit if amending

---
 lib/overcommit/hook_context/pre_commit.rb | 25 ++++++++++++++++++++---
 1 file changed, 22 insertions(+), 3 deletions(-)

diff --git a/lib/overcommit/hook_context/pre_commit.rb b/lib/overcommit/hook_context/pre_commit.rb
index 14ad3273..10088c71 100644
--- a/lib/overcommit/hook_context/pre_commit.rb
+++ b/lib/overcommit/hook_context/pre_commit.rb
@@ -78,7 +78,16 @@ def cleanup_environment
     # Get a list of added, copied, or modified files that have been staged.
     # Renames and deletions are ignored, since there should be nothing to check.
     def modified_files
-      @modified_files ||= Overcommit::GitRepo.modified_files(staged: true)
+      unless @modified_files
+        @modified_files = Overcommit::GitRepo.modified_files(staged: true)
+
+        # Include files modified in last commit if amending
+        if amend?
+          subcmd = 'show --format=%n'
+          @modified_files += Overcommit::GitRepo.modified_files(subcmd: subcmd)
+        end
+      end
+      @modified_files
     end
 
     # @deprecated
@@ -92,8 +101,18 @@ def modified_lines(file)
     # changed in a specified file.
     def modified_lines_in_file(file)
       @modified_lines ||= {}
-      @modified_lines[file] ||=
-        Overcommit::GitRepo.extract_modified_lines(file, staged: true)
+      unless @modified_lines[file]
+        @modified_lines[file] =
+          Overcommit::GitRepo.extract_modified_lines(file, staged: true)
+
+        # Include lines modified in last commit if amending
+        if amend?
+          subcmd = 'show --format=%n'
+          @modified_lines[file] +=
+            Overcommit::GitRepo.extract_modified_lines(file, subcmd: subcmd)
+        end
+      end
+      @modified_lines[file]
     end
 
     private

From 3eec82feb0f07f1a415a263d7c4872c5a7c80db4 Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Tue, 7 Apr 2015 21:46:38 -0400
Subject: [PATCH 10/18] Test #modified_files when amending last commit

---
 .../hook_context/pre_commit_spec.rb           | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/spec/overcommit/hook_context/pre_commit_spec.rb b/spec/overcommit/hook_context/pre_commit_spec.rb
index c63050a9..2cfa56fd 100644
--- a/spec/overcommit/hook_context/pre_commit_spec.rb
+++ b/spec/overcommit/hook_context/pre_commit_spec.rb
@@ -296,6 +296,10 @@
   describe '#modified_files' do
     subject { context.modified_files }
 
+    before do
+      context.stub(:amend?).and_return(false)
+    end
+
     it 'does not include submodules' do
       submodule = repo do
         `touch foo`
@@ -359,5 +363,22 @@
 
       it { should be_empty }
     end
+
+    context 'when amending last commit' do
+      around do |example|
+        repo do
+          FileUtils.touch('some-file')
+          `git add some-file`
+          `git commit -m 'Initial commit'`
+          example.run
+        end
+      end
+
+      before do
+        context.stub(:amend?).and_return(true)
+      end
+
+      it { should == [File.expand_path('some-file')] }
+    end
   end
 end

From b367eac55f01ebcb79c264bca46c471cdfd99894 Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Tue, 7 Apr 2015 21:47:00 -0400
Subject: [PATCH 11/18] Add specs for
 HookContext::PreCommit#modified_lines_in_file

---
 .../hook_context/pre_commit_spec.rb           | 54 +++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/spec/overcommit/hook_context/pre_commit_spec.rb b/spec/overcommit/hook_context/pre_commit_spec.rb
index 2cfa56fd..16f6f1aa 100644
--- a/spec/overcommit/hook_context/pre_commit_spec.rb
+++ b/spec/overcommit/hook_context/pre_commit_spec.rb
@@ -381,4 +381,58 @@
       it { should == [File.expand_path('some-file')] }
     end
   end
+
+  describe '#modified_lines_in_file' do
+    let(:modified_file) { 'some-file' }
+    subject { context.modified_lines_in_file(modified_file) }
+
+    before do
+      context.stub(:amend?).and_return(false)
+    end
+
+    context 'when file contains a trailing newline' do
+      around do |example|
+        repo do
+          File.open(modified_file, 'w') { |f| (1..3).each { |i| f.write("#{i}\n") } }
+          `git add #{modified_file}`
+          example.run
+        end
+      end
+
+      it { should == Set.new(1..3) }
+    end
+
+    context 'when file does not contain a trailing newline' do
+      around do |example|
+        repo do
+          File.open(modified_file, 'w') do |f|
+            (1..2).each { |i| f.write("#{i}\n") }
+            f.write(3)
+          end
+
+          `git add #{modified_file}`
+          example.run
+        end
+      end
+
+      it { should == Set.new(1..3) }
+    end
+
+    context 'when amending last commit' do
+      around do |example|
+        repo do
+          File.open(modified_file, 'w') { |f| (1..3).each { |i| f.write("#{i}\n") } }
+          `git add #{modified_file}`
+          `git commit -m "Add files"`
+          example.run
+        end
+      end
+
+      before do
+        context.stub(:amend?).and_return(true)
+      end
+
+      it { should == Set.new(1..3) }
+    end
+  end
 end

From 68a659d2bfb2ba8be159e60ff06d53050f54a857 Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Wed, 8 Apr 2015 00:56:38 -0400
Subject: [PATCH 12/18] DRY up 'before' blocks in #amend? specs

---
 .../overcommit/hook_context/pre_commit_spec.rb | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/spec/overcommit/hook_context/pre_commit_spec.rb b/spec/overcommit/hook_context/pre_commit_spec.rb
index 16f6f1aa..83b261bc 100644
--- a/spec/overcommit/hook_context/pre_commit_spec.rb
+++ b/spec/overcommit/hook_context/pre_commit_spec.rb
@@ -10,15 +10,19 @@
   describe '#amend?' do
     subject { context.amend? }
 
+    before do
+      Overcommit::Utils.stub(:parent_command).and_return(command)
+    end
+
     context 'when amending a commit using `git commit --amend`' do
-      before do
-        Overcommit::Utils.stub(:parent_command).and_return('git commit --amend')
-      end
+      let(:command) { 'git commit --amend' }
 
       it { should == true }
     end
 
     context 'when amending a commit using a git alias' do
+      let(:command) { 'git amend' }
+
       around do |example|
         repo do
           `git config alias.amend 'commit --amend'`
@@ -26,17 +30,11 @@
         end
       end
 
-      before do
-        Overcommit::Utils.stub(:parent_command).and_return('git amend')
-      end
-
       it { should == true }
     end
 
     context 'when not amending a commit' do
-      before do
-        Overcommit::Utils.stub(:parent_command).and_return('git commit')
-      end
+      let(:command) { 'git commit' }
 
       it { should == false }
     end

From c7dfa9996b1be1f82b58c979368712f89e317542 Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Wed, 8 Apr 2015 00:57:15 -0400
Subject: [PATCH 13/18] Add spec for git alias containing '--amend'

---
 .../hook_context/pre_commit_spec.rb           | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/spec/overcommit/hook_context/pre_commit_spec.rb b/spec/overcommit/hook_context/pre_commit_spec.rb
index 83b261bc..7bc47da8 100644
--- a/spec/overcommit/hook_context/pre_commit_spec.rb
+++ b/spec/overcommit/hook_context/pre_commit_spec.rb
@@ -34,9 +34,24 @@
     end
 
     context 'when not amending a commit' do
-      let(:command) { 'git commit' }
+      context 'using `git commit`' do
+        let(:command) { 'git commit' }
 
-      it { should == false }
+        it { should == false }
+      end
+
+      context 'using a git alias containing "--amend"' do
+        let(:command) { 'git no--amend' }
+
+        around do |example|
+          repo do
+            `git config alias.no--amend commit`
+            example.run
+          end
+        end
+
+        it { should == false }
+      end
     end
   end
 

From 1253bfd307162f02e3210a5f979d7aeb2772760d Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Wed, 8 Apr 2015 00:59:15 -0400
Subject: [PATCH 14/18] Rename #amend? to #amendment?

---
 lib/overcommit/hook_context/pre_commit.rb       |  6 +++---
 spec/overcommit/hook_context/pre_commit_spec.rb | 12 ++++++------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/lib/overcommit/hook_context/pre_commit.rb b/lib/overcommit/hook_context/pre_commit.rb
index 10088c71..713ccfe1 100644
--- a/lib/overcommit/hook_context/pre_commit.rb
+++ b/lib/overcommit/hook_context/pre_commit.rb
@@ -9,7 +9,7 @@ module Overcommit::HookContext
   # hooks only inspect staged changes.
   class PreCommit < Base # rubocop:disable ClassLength
     # Returns whether this hook run was triggered by `git commit --amend`
-    def amend?
+    def amendment?
       if @amended.nil?
         cmd = Overcommit::Utils.parent_command
         @amended = !(/--amend/ =~ cmd).nil?
@@ -82,7 +82,7 @@ def modified_files
         @modified_files = Overcommit::GitRepo.modified_files(staged: true)
 
         # Include files modified in last commit if amending
-        if amend?
+        if amendment?
           subcmd = 'show --format=%n'
           @modified_files += Overcommit::GitRepo.modified_files(subcmd: subcmd)
         end
@@ -106,7 +106,7 @@ def modified_lines_in_file(file)
           Overcommit::GitRepo.extract_modified_lines(file, staged: true)
 
         # Include lines modified in last commit if amending
-        if amend?
+        if amendment?
           subcmd = 'show --format=%n'
           @modified_lines[file] +=
             Overcommit::GitRepo.extract_modified_lines(file, subcmd: subcmd)
diff --git a/spec/overcommit/hook_context/pre_commit_spec.rb b/spec/overcommit/hook_context/pre_commit_spec.rb
index 7bc47da8..b32e6f3d 100644
--- a/spec/overcommit/hook_context/pre_commit_spec.rb
+++ b/spec/overcommit/hook_context/pre_commit_spec.rb
@@ -7,8 +7,8 @@
   let(:input) { double('input') }
   let(:context) { described_class.new(config, args, input) }
 
-  describe '#amend?' do
-    subject { context.amend? }
+  describe '#amendment?' do
+    subject { context.amendment? }
 
     before do
       Overcommit::Utils.stub(:parent_command).and_return(command)
@@ -310,7 +310,7 @@
     subject { context.modified_files }
 
     before do
-      context.stub(:amend?).and_return(false)
+      context.stub(:amendment?).and_return(false)
     end
 
     it 'does not include submodules' do
@@ -388,7 +388,7 @@
       end
 
       before do
-        context.stub(:amend?).and_return(true)
+        context.stub(:amendment?).and_return(true)
       end
 
       it { should == [File.expand_path('some-file')] }
@@ -400,7 +400,7 @@
     subject { context.modified_lines_in_file(modified_file) }
 
     before do
-      context.stub(:amend?).and_return(false)
+      context.stub(:amendment?).and_return(false)
     end
 
     context 'when file contains a trailing newline' do
@@ -442,7 +442,7 @@
       end
 
       before do
-        context.stub(:amend?).and_return(true)
+        context.stub(:amendment?).and_return(true)
       end
 
       it { should == Set.new(1..3) }

From 808b7d92e4afb7dcb9f7eeb18e3cb5ec3888ef1a Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Wed, 8 Apr 2015 01:38:56 -0400
Subject: [PATCH 15/18] Clean up #amendment? and add comments for clarity

---
 lib/overcommit/hook_context/pre_commit.rb | 27 +++++++++++++++--------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/lib/overcommit/hook_context/pre_commit.rb b/lib/overcommit/hook_context/pre_commit.rb
index 713ccfe1..d717a6de 100644
--- a/lib/overcommit/hook_context/pre_commit.rb
+++ b/lib/overcommit/hook_context/pre_commit.rb
@@ -10,16 +10,25 @@ module Overcommit::HookContext
   class PreCommit < Base # rubocop:disable ClassLength
     # Returns whether this hook run was triggered by `git commit --amend`
     def amendment?
-      if @amended.nil?
-        cmd = Overcommit::Utils.parent_command
-        @amended = !(/--amend/ =~ cmd).nil?
-
-        amend_alias = `git config --get-regexp '^alias\\.' '--amend'`.
-          slice(/(?<=alias\.)\w+/)
+      return @amendment unless @amendment.nil?
+
+      cmd = Overcommit::Utils.parent_command
+      amend_pattern = 'commit(\s.*)?\s--amend(\s|$)'
+
+      return @amendment if
+        # True if the command is a commit with the --amend flag
+        @amendment = !(/\s#{amend_pattern}/ =~ cmd).nil?
+
+      # Check for git aliases that call `commit --amend`
+      `git config --get-regexp '^alias\\.' '#{amend_pattern}'`.
+        scan(/alias\.([-\w]+)/). # Extract the alias
+        each do |amend_alias|
+          return @amendment if
+            # True if the command uses a git alias for `commit --amend`
+            @amendment = !(/git\s+#{amend_alias}/ =~ cmd).nil?
+        end
 
-        @amended ||= !(/git #{amend_alias}/ =~ cmd).nil? unless amend_alias.nil?
-      end
-      @amended
+      @amendment
     end
 
     # Stash unstaged contents of files so hooks don't see changes that aren't

From 735545ea6687b0ac2160e7dfe3c956f93057bb53 Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Wed, 8 Apr 2015 01:52:43 -0400
Subject: [PATCH 16/18] Add spec for multiple git aliases that call 'commit
 --amend'

---
 spec/overcommit/hook_context/pre_commit_spec.rb | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/spec/overcommit/hook_context/pre_commit_spec.rb b/spec/overcommit/hook_context/pre_commit_spec.rb
index b32e6f3d..79dbbb6d 100644
--- a/spec/overcommit/hook_context/pre_commit_spec.rb
+++ b/spec/overcommit/hook_context/pre_commit_spec.rb
@@ -21,16 +21,25 @@
     end
 
     context 'when amending a commit using a git alias' do
-      let(:command) { 'git amend' }
-
       around do |example|
         repo do
           `git config alias.amend 'commit --amend'`
+          `git config alias.other-amend 'commit --amend'`
           example.run
         end
       end
 
-      it { should == true }
+      context 'when using one of multiple aliases' do
+        let(:command) { 'git amend' }
+
+        it { should == true }
+      end
+
+      context 'when using another of multiple aliases' do
+        let(:command) { 'git other-amend' }
+
+        it { should == true }
+      end
     end
 
     context 'when not amending a commit' do

From fbd04dae3967a625f58598349d8d4e1d6537693b Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Wed, 8 Apr 2015 01:53:57 -0400
Subject: [PATCH 17/18] Extract alias from match array

---
 lib/overcommit/hook_context/pre_commit.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/overcommit/hook_context/pre_commit.rb b/lib/overcommit/hook_context/pre_commit.rb
index d717a6de..c7c82ec7 100644
--- a/lib/overcommit/hook_context/pre_commit.rb
+++ b/lib/overcommit/hook_context/pre_commit.rb
@@ -22,10 +22,10 @@ def amendment?
       # Check for git aliases that call `commit --amend`
       `git config --get-regexp '^alias\\.' '#{amend_pattern}'`.
         scan(/alias\.([-\w]+)/). # Extract the alias
-        each do |amend_alias|
+        each do |match|
           return @amendment if
             # True if the command uses a git alias for `commit --amend`
-            @amendment = !(/git\s+#{amend_alias}/ =~ cmd).nil?
+            @amendment = !(/git\s+#{match[0]}/ =~ cmd).nil?
         end
 
       @amendment

From d2dacb74b16f57e62c271a0fa4b108f8b35e25a5 Mon Sep 17 00:00:00 2001
From: Josh Hagins <hagins.josh@gmail.com>
Date: Wed, 8 Apr 2015 02:00:56 -0400
Subject: [PATCH 18/18] Check that result sets are merged when amending

---
 spec/overcommit/hook_context/pre_commit_spec.rb | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/spec/overcommit/hook_context/pre_commit_spec.rb b/spec/overcommit/hook_context/pre_commit_spec.rb
index 79dbbb6d..0d4cd8fb 100644
--- a/spec/overcommit/hook_context/pre_commit_spec.rb
+++ b/spec/overcommit/hook_context/pre_commit_spec.rb
@@ -392,6 +392,8 @@
           FileUtils.touch('some-file')
           `git add some-file`
           `git commit -m 'Initial commit'`
+          FileUtils.touch('other-file')
+          `git add other-file`
           example.run
         end
       end
@@ -400,7 +402,7 @@
         context.stub(:amendment?).and_return(true)
       end
 
-      it { should == [File.expand_path('some-file')] }
+      it { should =~ [File.expand_path('some-file'), File.expand_path('other-file')] }
     end
   end
 
@@ -446,6 +448,8 @@
           File.open(modified_file, 'w') { |f| (1..3).each { |i| f.write("#{i}\n") } }
           `git add #{modified_file}`
           `git commit -m "Add files"`
+          File.open(modified_file, 'a') { |f| f.puts 4 }
+          `git add #{modified_file}`
           example.run
         end
       end
@@ -454,7 +458,7 @@
         context.stub(:amendment?).and_return(true)
       end
 
-      it { should == Set.new(1..3) }
+      it { should == Set.new(1..4) }
     end
   end
 end