Merge pull request #10 from CatanaCorp/ec-mode-bits

Add a way to check if the diff applies to a symlink or an executable

lib/github_diff_parser.rb

@@ -3,6 +3,7 @@
 require_relative "github_diff_parser/version"
 
 module GithubDiffParser
+  Error = Class.new(StandardError)
   InvalidDiff = Class.new(ArgumentError)
 
   autoload :Parser,  "github_diff_parser/parser"

lib/github_diff_parser/diff.rb

@@ -2,6 +2,8 @@
 
 module GithubDiffParser
   class Diff
+    Mode = Struct.new(:operation, :bits)
+
     # @return [String] (see #initialize)
     attr_reader :previous_filename
 
@@ -20,7 +22,10 @@ class Diff
     attr_reader :new_index
 
     # @private
-    attr_writer :file_mode, :previous_index, :new_index
+    attr_writer :previous_index, :new_index
+
+    # @private
+    attr_accessor :mode
 
     # @param previous_filename [String] the original filename. Represented by "diff --git /a filename"
     # @param new_filename [String]      the new filename. Represented by "diff --git /b filename"
@@ -73,7 +78,7 @@ def add_line(line_content, type:)
     #
     # @return [Boolean]
     def deleted_mode?
-      @file_mode == "deleted"
+      @mode.operation == "deleted"
     end
 
     # Check if this Diff is set to new mode.
@@ -89,7 +94,7 @@ def deleted_mode?
     #
     # @return [Boolean]
     def new_mode?
-      @file_mode == "new"
+      @mode.operation == "new"
     end
 
     # Check if this Diff is set to rename mode.
@@ -105,6 +110,29 @@ def rename_mode?
       previous_filename != new_filename
     end
 
+    # @return [Boolean] True if this diff applies to a regular file.
+    def normal_file?
+      @mode.bits == "100644"
+    end
+
+    # @return [Boolean] True if this diff applies to an executable.
+    def executable?
+      @mode.bits == "100755"
+    end
+
+    # @return [Boolean] True if this diff applies to a symlink.
+    def symlink?
+      @mode.bits == "120000"
+    end
+
+    # @return [String] The source of the symlink
+    # @raise If this diff doesn't apply to a symlink
+    def symlink_source
+      raise(Error, "This diff doen't apply to a symbolic link") unless symlink?
+
+      lines.first.content
+    end
+
     # A utility method that returns the current number of a line who might not be present in the diff.
     # This is useful if you need to keep track of the updated line numbers in a file for every changes.
     #

lib/github_diff_parser/parser.rb

@@ -57,6 +57,7 @@ def process_index(match_data)
 
       @current_diff.previous_index = match_data[:previous_index]
       @current_diff.new_index = match_data[:new_index]
+      @current_diff.mode ||= Diff::Mode.new("modified", match_data[:bits])
     end
 
     # Called when encountering a `new file mode 100644` or `delete file mode 100644` in the Git Diff output.
@@ -67,7 +68,7 @@ def process_index(match_data)
     def process_diff_file_mode(match_data)
       validate_diff
 
-      @current_diff.file_mode = match_data[:file_mode]
+      @current_diff.mode = Diff::Mode.new(match_data[:file_mode], match_data[:bits])
     end
 
     # Called when encountering a `@@ -0,0 +1,10 @@` in the Git Diff output.

lib/github_diff_parser/regexes.rb

@@ -33,7 +33,8 @@ module Regexes
       index\s                                          # Match 'index '
       (?<previous_index>[a-z0-9]+)                     # Match and capture alphanumerical chars
       ..                                               # Match '..' literally
-      (?<new_index>[a-z0-9]+)                          # Match and captuer alphanumerical chars
+      (?<new_index>[a-z0-9]+)\s                        # Match and capture alphanumerical chars
+      (?<bits>\d+)?                                    # Optionaly capture the mode bits
     }x
 
     # This Regexp is used to match the header containing the original filename.
@@ -88,7 +89,7 @@ module Regexes
     MODE_HEADER = %r{
       \A                                               # Start of line
       (?<file_mode>new|deleted)                        # Match 'new' or 'deleted' and capture the group
-      \sfile\smode\s\d+                                # Match ' file mode 100655'
+      \sfile\smode\s(?<bits>\d+)                       # Match ' file mode 100655' and capture the "100655" part
       \Z                                               # End of line
     }x
 

test/data/file_modes.diff

@@ -0,0 +1,11 @@
+diff --git a/my_executable.rb b/my_executable.rb
+new file mode 100755
+index 0000000..e69de29
+diff --git a/some_other_file b/some_other_file
+new file mode 120000
+index 0000000..c2e492f
+--- /dev/null
++++ b/some_other_file
+@@ -0,0 +1 @@
++some_file.rb
+\ No newline at end of file

test/github_diff_parser_test.rb

@@ -29,6 +29,7 @@ def test_line_added
     expected_lines.each_with_index do |expected_line, index|
       assert_line(expected_line, hunk.lines[index])
     end
+    assert_predicate(parsed_diff, :normal_file?)
   end
 
   def test_line_removed
@@ -57,6 +58,7 @@ def test_line_removed
     expected_lines.each_with_index do |expected_line, index|
       assert_line(expected_line, hunk.lines[index])
     end
+    assert_predicate(parsed_diff, :normal_file?)
   end
 
   def test_line_changed
@@ -87,6 +89,7 @@ def test_line_changed
     expected_lines.each_with_index do |expected_line, index|
       assert_line(expected_line, hunk.lines[index])
     end
+    assert_predicate(parsed_diff, :normal_file?)
   end
 
   def test_file_added
@@ -119,6 +122,7 @@ def test_file_added
     expected_lines.each_with_index do |expected_line, index|
       assert_line(expected_line, hunk.lines[index])
     end
+    assert_predicate(parsed_diff, :normal_file?)
   end
 
   def test_file_removed
@@ -152,6 +156,7 @@ def test_file_removed
     expected_lines.each_with_index do |expected_line, index|
       assert_line(expected_line, hunk.lines[index])
     end
+    assert_predicate(parsed_diff, :normal_file?)
   end
 
   def test_file_moved
@@ -192,6 +197,7 @@ def test_rails_diff
     expected_lines.each_with_index do |expected_line, index|
       assert_line(expected_line, hunk.lines[index])
     end
+    assert_predicate(parsed_diff, :normal_file?)
 
     hunk = parsed_diff.hunks[1]
     assert_equal(18, hunk.lines.count)
@@ -223,6 +229,7 @@ def test_rails_diff
     expected_lines.each_with_index do |expected_line, index|
       assert_line(expected_line, hunk.lines[index])
     end
+    assert_predicate(parsed_diff, :normal_file?)
   end
 
   def test_when_range_header_has_no_comma
@@ -255,6 +262,17 @@ def test_when_range_header_has_no_comma
     end
   end
 
+  def test_mode_bits
+    parsed_diffs = GithubDiffParser.parse(read_diff("file_modes"))
+
+    assert_equal(2, parsed_diffs.count)
+    assert_predicate(parsed_diffs.first, :executable?)
+    assert_raises(GithubDiffParser::Error) { parsed_diffs.first.symlink_source }
+
+    assert_predicate(parsed_diffs[1], :symlink?)
+    assert_equal("some_file.rb", parsed_diffs[1].symlink_source)
+  end
+
   def test_raise_when_diff_is_not_a_diff
     assert_raises(GithubDiffParser::InvalidDiff) do
       GithubDiffParser.parse(read_diff("invalid"))