module Git::Parsers::Diff

Parser for git diff output in various formats

Handles parsing of –numstat, –shortstat, –dirstat, –raw, and –patch output. This parser is used by stash show, diff, show, and log commands.

@note Combined/merge diffs (e.g., from ‘git diff –cc` or `git show <merge>`) are not

supported. These have a different format with multiple +/- columns per parent.

## Design Note: Namespace Organization

This parser creates and returns {Git::DiffResult} and {Git::DiffFile*Info} objects, which live at the top-level ‘Git::` namespace rather than within `Git::Parsers::`. This is intentional:

**Parsers are infrastructure** - marked ‘@api private`, users shouldn’t interact with them directly
**Info/Result classes are public API** - returned by commands and used throughout the codebase
**Info classes are domain entities** - represent git diff data
**Result classes are operation outcomes** - represent command results, not parsing details

Keeping Info/Result classes at ‘Git::` improves discoverability and correctly reflects their role as public types rather than parser internals.

@api private

Constants

BRACE_RENAME_PATTERN

Brace-expanded rename format from git numstat -M output

NULL_MODE

Null mode for non-existent files

NULL_SHA

Null SHA for non-existent files

RENAME_PATTERN

Rename format patterns from git numstat -M output:

old_name.rb => new_name.rb
\\{old_dir => new_dir}/file.rb
dir/\\{old_name.rb => new_name.rb}

STATUS_MAP

Status letter to symbol mapping for –raw output

Public Instance Methods

build_result (files:, shortstat:, dirstat:)

Source

# File lib/git/parsers/diff.rb, line 76
def build_result(files:, shortstat:, dirstat:)
  Git::DiffResult.new(
    files_changed: shortstat[:files_changed],
    total_insertions: shortstat[:insertions],
    total_deletions: shortstat[:deletions],
    files: files,
    dirstat: dirstat
  )
end

Build a DiffResult from parsed components

@param files [Array] array of file info objects

@param shortstat [Hash] parsed shortstat data

@param dirstat [Git::DirstatInfo, nil] parsed dirstat data

@return [Git::DiffResult]

empty_result ()

Source

# File lib/git/parsers/diff.rb, line 90
def empty_result
  Git::DiffResult.new(
    files_changed: 0, total_insertions: 0, total_deletions: 0,
    files: [], dirstat: nil
  )
end

Build an empty DiffResult

@return [Git::DiffResult]

parse_dirstat (lines)

Source

# File lib/git/parsers/diff.rb, line 127
def parse_dirstat(lines)
  entries = lines.filter_map do |line|
    next unless (match = line.match(/^\s*([\d.]+)%\s+(.+)$/))

    Git::DirstatEntry.new(percentage: match[1].to_f, directory: match[2])
  end
  Git::DirstatInfo.new(entries: entries)
end

Parse dirstat lines into DirstatInfo

@example

parse_dirstat(["  50.0% lib/", "  50.0% spec/"])
# => #<Git::DirstatInfo entries: [...]>

@param lines [Array<String>] dirstat output lines

@return [Git::DirstatInfo]

parse_shortstat (line)

Source

# File lib/git/parsers/diff.rb, line 107
def parse_shortstat(line)
  return { files_changed: 0, insertions: 0, deletions: 0 } if line.nil?

  {
    files_changed: line.match(/(\d+)\s+files?\s+changed/)&.[](1).to_i,
    insertions: line.match(/(\d+)\s+insertions?\(\+\)/)&.[](1).to_i,
    deletions: line.match(/(\d+)\s+deletions?\(-\)/)&.[](1).to_i
  }
end

Parse shortstat line into components

@example

parse_shortstat(" 3 files changed, 10 insertions(+), 5 deletions(-)")
# => { files_changed: 3, insertions: 10, deletions: 5 }

@param line [String, nil] the shortstat line

@return [Hash] { files_changed:, insertions:, deletions: }

parse_stat_value (value)

Source

# File lib/git/parsers/diff.rb, line 142
def parse_stat_value(value)
  value == '-' ? 0 : value.to_i
end

Parse a stat value (handles ‘-’ for binary files)

@param value [String] the stat value string

@return [Integer] the numeric value (0 for binary files)

unescape_path (path)

Source

# File lib/git/parsers/diff.rb, line 152
def unescape_path(path)
  return path unless path&.start_with?('"') && path.end_with?('"')

  Git::EscapedPath.new(path[1..-2]).unescape
end

Unescape quoted path from git output

@param path [String] potentially quoted path

@return [String] unescaped path