class Git::CommandLine

Runs a git command and returns the result

@api public

Constants

RUN_ARGS

Attributes

binary_path[R]

@attribute [r] binary_path

The path to the command line binary to run

@example

binary_path = '/usr/bin/git'
command_line = Git::CommandLine.new({}, binary_path, ['version'], Logger.new(STDOUT))
command_line.binary_path #=> '/usr/bin/git'

@return [String]

env[R]

@attribute [r] env

Variables to set (or unset) in the git command’s environment

@example

env = { 'GIT_DIR' => '/path/to/git/dir' }
command_line = Git::CommandLine.new(env, '/usr/bin/git', [], Logger.new(STDOUT))
command_line.env #=> { 'GIT_DIR' => '/path/to/git/dir' }

@return [Hash<String, String>]

@see ruby-doc.org/3.2.1/Process.html#method-c-spawn Process.spawn

for details on how to set environment variables using the `env` parameter
global_opts[R]

@attribute [r] global_opts

The global options to pass to git

These are options that are passed to git before the command name and arguments. For example, in ‘git –git-dir /path/to/git/dir version`, the global options are %w[–git-dir /path/to/git/dir].

@example

env = {}
global_opts = %w[--git-dir /path/to/git/dir]
logger = Logger.new(nil)
cli = CommandLine.new(env, '/usr/bin/git', global_opts, logger)
cli.global_opts #=> %w[--git-dir /path/to/git/dir]

@return [Array<String>]

logger[R]

@attribute [r] logger

The logger to use for logging git commands and results

@example

env = {}
global_opts = %w[]
logger = Logger.new(STDOUT)
cli = CommandLine.new(env, '/usr/bin/git', global_opts, logger)
cli.logger == logger #=> true

@return [Logger]

Public Class Methods

new(env, binary_path, global_opts, logger) click to toggle source

Create a Git::CommandLine object

@example

env = { 'GIT_DIR' => '/path/to/git/dir' }
binary_path = '/usr/bin/git'
global_opts = %w[--git-dir /path/to/git/dir]
logger = Logger.new(STDOUT)
cli = CommandLine.new(env, binary_path, global_opts, logger)
cli.run('version') #=> #<Git::CommandLineResult:0x00007f9b0c0b0e00

@param env [Hash<String, String>] environment variables to set @param global_opts [Array<String>] global options to pass to git @param logger [Logger] the logger to use

# File lib/git/command_line.rb, line 28
def initialize(env, binary_path, global_opts, logger)
  @env = env
  @binary_path = binary_path
  @global_opts = global_opts
  @logger = logger
end

Public Instance Methods

run(*, **options_hash) click to toggle source

Execute a git command, wait for it to finish, and return the result

Non-option the command line arguements to pass to git. If you collect the command line arguments in an array, make sure you splat the array into the parameter list.

NORMALIZATION

The command output is returned as a Unicde string containing the binary output from the command. If the binary output is not valid UTF-8, the output will cause problems because the encoding will be invalid.

Normalization is a process that trys to convert the binary output to a valid UTF-8 string. It uses the ‘rchardet` gem to detect the encoding of the binary output and then converts it to UTF-8.

Normalization is not enabled by default. Pass ‘normalize: true` to Git::CommandLine#run to enable it. Normalization will only be performed on stdout and only if the `out:“ option is nil or is a StringIO object. If the out: option is set to a file or other IO object, the normalize option will be ignored.

@example Run a command and return the output

cli.run('version') #=> "git version 2.39.1\n"

@example The args array should be splatted into the parameter list

args = %w[log -n 1 --oneline]
cli.run(*args) #=> "f5baa11 beginning of Ruby/Git project\n"

@example Run a command and return the chomped output

cli.run('version', chomp: true) #=> "git version 2.39.1"

@example Run a command and without normalizing the output

cli.run('version', normalize: false) #=> "git version 2.39.1\n"

@example Capture stdout in a temporary file

require 'tempfile'
tempfile = Tempfile.create('git') do |file|
  cli.run('version', out: file)
  file.rewind
  file.read #=> "git version 2.39.1\n"
end

@example Capture stderr in a StringIO object

require 'stringio'
stderr = StringIO.new
begin
  cli.run('log', 'nonexistent-branch', err: stderr)
rescue Git::FailedError => e
  stderr.string #=> "unknown revision or path not in the working tree.\n"
end

@param options_hash [Hash] the options to pass to the command

@option options_hash [#write, nil] :out the object to write stdout to or nil to ignore stdout

If this is a 'StringIO' object, then `stdout_writer.string` will be returned.

In general, only specify a `stdout_writer` object when you want to redirect
stdout to a file or some other object that responds to `#write`. The default
behavior will return the output of the command.

@option options_hash [#write, nil] :err the object to write stderr to or nil to ignore stderr

If this is a 'StringIO' object and `merged_output` is `true`, then
`stderr_writer.string` will be merged into the output returned by this method.

@option options_hash [Boolean] :normalize whether to normalize the output of stdout and stderr

@option options_hash [Boolean] :chomp whether to chomp both stdout and stderr output

@option options_hash [Boolean] :merge whether to merge stdout and stderr in the string returned

@option options_hash [String, nil] :chdir the directory to run the command in

@option options_hash [Numeric, nil] :timeout the maximum seconds to wait for the command to complete

If timeout is zero, the timeout will not be enforced.

If the command times out, it is killed via a `SIGKILL` signal and `Git::TimeoutError` is raised.

If the command does not respond to SIGKILL, it will hang this method.

@return [Git::CommandLineResult] the output of the command

This result of running the command.

@raise [ArgumentError] if ‘args` is not an array of strings

@raise [Git::SignaledError] if the command was terminated because of an uncaught signal

@raise [Git::FailedError] if the command returned a non-zero exitstatus

@raise [Git::ProcessIOError] if an exception was raised while collecting subprocess output

@raise [Git::TimeoutError] if the command times out

# File lib/git/command_line.rb, line 194
def run(*, **options_hash)
  options_hash = RUN_ARGS.merge(options_hash)
  extra_options = options_hash.keys - RUN_ARGS.keys
  raise ArgumentError, "Unknown options: #{extra_options.join(', ')}" if extra_options.any?

  result = run_with_capture(*, **options_hash)
  process_result(result, options_hash[:normalize], options_hash[:chomp], options_hash[:timeout])
end
run_with_capture(*args, **options_hash) click to toggle source

@return [Git::CommandLineResult] the result of running the command

@api private

# File lib/git/command_line.rb, line 207
def run_with_capture(*args, **options_hash)
  git_cmd = build_git_cmd(args)
  options = run_with_capture_options(**options_hash)
  ProcessExecuter.run_with_capture(env, *git_cmd, **options)
rescue ProcessExecuter::ProcessIOError => e
  raise Git::ProcessIOError.new(e.message), cause: e.exception.cause
end
run_with_capture_options(**options_hash) click to toggle source
# File lib/git/command_line.rb, line 215
def run_with_capture_options(**options_hash)
  chdir = options_hash[:chdir] || :not_set
  timeout_after = options_hash[:timeout]
  out = options_hash[:out]
  err = options_hash[:err]
  merge_output = options_hash[:merge] || false

  { chdir:, timeout_after:, merge_output:, raise_errors: false }.tap do |options|
    options[:out] = out unless out.nil?
    options[:err] = err unless err.nil?
  end
end

Private Instance Methods

build_git_cmd(args) click to toggle source

Build the git command line from the available sources to send to ‘Process.spawn` @return [Array<String>] @api private

# File lib/git/command_line.rb, line 244
def build_git_cmd(args)
  raise ArgumentError, 'The args array can not contain an array' if args.any? { |a| a.is_a?(Array) }

  [binary_path, *global_opts, *args].map(&:to_s)
end
command_line_result(command, result, processed_out, processed_err, timeout) click to toggle source
# File lib/git/command_line.rb, line 291
def command_line_result(command, result, processed_out, processed_err, timeout)
  Git::CommandLineResult.new(command, result, processed_out, processed_err).tap do |processed_result|
    raise Git::TimeoutError.new(processed_result, timeout) if result.timeout?

    raise Git::SignaledError, processed_result if result.signaled?

    raise Git::FailedError, processed_result unless result.success?
  end
end
log_result(result, command, processed_out, processed_err) click to toggle source
# File lib/git/command_line.rb, line 286
def log_result(result, command, processed_out, processed_err)
  logger.info { "#{command} exited with status #{result}" }
  logger.debug { "stdout:\n#{processed_out.inspect}\nstderr:\n#{processed_err.inspect}" }
end
post_process_output(result, normalize, chomp) click to toggle source

Post-process and return an array of raw output strings

For each raw output string:

  • If normalize: is true, normalize the encoding by transcoding each line from the detected encoding to UTF-8.

  • If chomp: is true chomp the output after normalization.

Even if no post-processing is done based on the options, the strings returned are a copy of the raw output strings. The raw output strings are not modified.

@param result [ProcessExecuter::ResultWithCapture] the command’s output to post-process

@param normalize [Boolean] whether to normalize the output of each writer @param chomp [Boolean] whether to chomp the output of each writer

@return [Array<String>]

@api private

# File lib/git/command_line.rb, line 321
def post_process_output(result, normalize, chomp)
  [result.stdout, result.stderr].map do |raw_output|
    output = raw_output.dup
    output = output.lines.map { |l| Git::EncodingUtils.normalize_encoding(l) }.join if normalize
    output.chomp! if chomp
    output
  end
end
process_result(result, normalize, chomp, timeout) click to toggle source

Process the result of the command and return a Git::CommandLineResult

Post process output, log the command and result, and raise an error if the command failed.

@param result [ProcessExecuter::Command::Result] the result it is a

Process::Status and include command, stdout, and stderr

@param normalize [Boolean] whether to normalize the output of each writer

@param chomp [Boolean] whether to chomp the output of each writer

@param timeout [Numeric, nil] the maximum seconds to wait for the command to

complete

@return [Git::CommandLineResult] the result of the command to return to the

caller

@raise [Git::FailedError] if the command failed

@raise [Git::SignaledError] if the command was signaled

@raise [Git::TimeoutError] if the command times out

@raise [Git::ProcessIOError] if an exception was raised while collecting

subprocess output

@api private

# File lib/git/command_line.rb, line 279
def process_result(result, normalize, chomp, timeout)
  command = result.command
  processed_out, processed_err = post_process_output(result, normalize, chomp)
  log_result(result, command, processed_out, processed_err)
  command_line_result(command, result, processed_out, processed_err, timeout)
end