class Overcommit::HookContext::PreCommit
Contains helpers related to contextual information used by pre-commit hooks.
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.
Public Instance Methods
Returns whether this hook run was triggered by `git commit –amend`
# File lib/overcommit/hook_context/pre_commit.rb, line 14 def amendment? return @amendment unless @amendment.nil? cmd = Overcommit::Utils.parent_command return unless cmd amend_pattern = 'commit(\s.*)?\s--amend(\s|$)' # Since the ps command can return invalid byte sequences for commands # containing unicode characters, we replace the offending characters, # since the pattern we're looking for will consist of ASCII characters unless cmd.valid_encoding? cmd = Overcommit::Utils.parent_command.encode('UTF-16be', invalid: :replace, replace: '?'). encode('UTF-8') end 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 |match| return @amendment if # True if the command uses a git alias for `commit --amend` @amendment = !(/git(\.exe)?\s+#{match[0]}/ =~ cmd).nil? end @amendment end
Restore unstaged changes and reset file modification times so it appears as if nothing ever changed.
We want to restore the modification times for each of the files after every step to ensure as little time as possible has passed while the modification time on the file was newer. This helps us play more nicely with file watchers.
# File lib/overcommit/hook_context/pre_commit.rb, line 70 def cleanup_environment if @changes_stashed clear_working_tree restore_working_tree restore_modified_times end Overcommit::GitRepo.restore_merge_state Overcommit::GitRepo.restore_cherry_pick_state end
Returns whether the current git branch is empty (has no commits).
# File lib/overcommit/hook_context/pre_commit.rb, line 117 def initial_commit? return @initial_commit unless @initial_commit.nil? @initial_commit = Overcommit::GitRepo.initial_commit? end
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.
# File lib/overcommit/hook_context/pre_commit.rb, line 83 def modified_files unless @modified_files currently_staged = Overcommit::GitRepo.modified_files(staged: true) @modified_files = currently_staged # Include files modified in last commit if amending if amendment? subcmd = 'show --format=%n' previously_modified = Overcommit::GitRepo.modified_files(subcmd: subcmd) @modified_files |= filter_modified_files(previously_modified) end end @modified_files end
Returns the set of line numbers corresponding to the lines that were changed in a specified file.
# File lib/overcommit/hook_context/pre_commit.rb, line 100 def modified_lines_in_file(file) @modified_lines ||= {} unless @modified_lines[file] @modified_lines[file] = Overcommit::GitRepo.extract_modified_lines(file, staged: true) # Include lines modified in last commit if amending if amendment? subcmd = 'show --format=%n' @modified_lines[file] += Overcommit::GitRepo.extract_modified_lines(file, subcmd: subcmd) end end @modified_lines[file] end
Stash unstaged contents of files so hooks don't see changes that aren't about to be committed.
# File lib/overcommit/hook_context/pre_commit.rb, line 47 def setup_environment store_modified_times Overcommit::GitRepo.store_merge_state Overcommit::GitRepo.store_cherry_pick_state # Don't attempt to stash changes if all changes are staged, as this # prevents us from modifying files at all, which plays better with # editors/tools which watch for file changes. if !initial_commit? && unstaged_changes? stash_changes # While running hooks make it appear as if nothing changed restore_modified_times end end
Private Instance Methods
Clears the working tree so that the stash can be applied.
# File lib/overcommit/hook_context/pre_commit.rb, line 146 def clear_working_tree removed_submodules = Overcommit::GitRepo.staged_submodule_removals result = Overcommit::Utils.execute(%w[git reset --hard]) unless result.success? raise Overcommit::Exceptions::HookCleanupFailed, "Unable to cleanup working tree after #{hook_script_name} hooks run:" \ "\nSTDOUT:#{result.stdout}\nSTDERR:#{result.stderr}" end # Hard-resetting a staged submodule removal results in the index being # reset but the submodule being restored as an empty directory. This empty # directory prevents us from stashing on a subsequent run if a hook fails. # # Work around this by removing these empty submodule directories as there # doesn't appear any reason to keep them around. removed_submodules.each do |submodule| FileUtils.rmdir(submodule.path) end end
Restores the file modification times for all modified files to make it appear like they never changed.
# File lib/overcommit/hook_context/pre_commit.rb, line 204 def restore_modified_times @modified_times.each do |file, time| next if Overcommit::Utils.broken_symlink?(file) next unless File.exist?(file) File.utime(time, time, file) end end
Applies the stash to the working tree to restore the user's state.
# File lib/overcommit/hook_context/pre_commit.rb, line 168 def restore_working_tree result = Overcommit::Utils.execute(%w[git stash pop --index --quiet]) unless result.success? raise Overcommit::Exceptions::HookCleanupFailed, "Unable to restore working tree after #{hook_script_name} hooks run:" \ "\nSTDOUT:#{result.stdout}\nSTDERR:#{result.stderr}" end end
# File lib/overcommit/hook_context/pre_commit.rb, line 124 def stash_changes @stash_attempted = true stash_message = "Overcommit: Stash of repo state before hook run at #{Time.now}" result = Overcommit::Utils.with_environment('GIT_LITERAL_PATHSPECS' => '0') do Overcommit::Utils.execute( %w[git -c commit.gpgsign=false stash save --keep-index --quiet] + [stash_message] ) end unless result.success? # Failure to stash in this case is likely due to a configuration # issue (e.g. author/email not set or GPG signing key incorrect) raise Overcommit::Exceptions::HookSetupFailed, "Unable to setup environment for #{hook_script_name} hook run:" \ "\nSTDOUT:#{result.stdout}\nSTDERR:#{result.stderr}" end @changes_stashed = `git stash list -1`.include?(stash_message) end
Stores the modification times for all modified files to make it appear like they never changed.
This prevents (some) editors from complaining about files changing when we stash changes before running the hooks.
# File lib/overcommit/hook_context/pre_commit.rb, line 189 def store_modified_times @modified_times = {} staged_files = modified_files unstaged_files = Overcommit::GitRepo.modified_files(staged: false) (staged_files + unstaged_files).each do |file| next if Overcommit::Utils.broken_symlink?(file) next unless File.exist?(file) # Ignore renamed files (old file no longer exists) @modified_times[file] = File.mtime(file) end end
Returns whether there are any changes to tracked files which have not yet been staged.
# File lib/overcommit/hook_context/pre_commit.rb, line 179 def unstaged_changes? result = Overcommit::Utils.execute(%w[git --no-pager diff --quiet]) !result.success? end