diff options
author | Douwe Maan <douwe@selenight.nl> | 2016-07-11 08:08:01 +0300 |
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committer | Douwe Maan <douwe@selenight.nl> | 2016-07-12 02:58:15 +0300 |
commit | f5cc3f63a8a6a44e755aa81ac6cba8e544b848e6 (patch) | |
tree | 4bed51ba54e4fe9fd4d64c3581c1aaaa4d70e40b /lib | |
parent | 92772f85c1c68858b962b4934f3c5ee2e0849c14 (diff) |
Render inline diffs for multiple changed lines following eachother
Diffstat (limited to 'lib')
-rw-r--r-- | lib/gitlab/diff/inline_diff.rb | 52 |
1 files changed, 38 insertions, 14 deletions
diff --git a/lib/gitlab/diff/inline_diff.rb b/lib/gitlab/diff/inline_diff.rb index 789c14518b0..72d9abeefcc 100644 --- a/lib/gitlab/diff/inline_diff.rb +++ b/lib/gitlab/diff/inline_diff.rb @@ -1,16 +1,30 @@ module Gitlab module Diff class InlineDiff + # Regex to find a run of deleted lines followed by the same number of added lines + REGEX = %r{ + # Runs start at the beginning of the string (the first line) or after a space (for an unchanged line) + (?:\A| ) + + # This matches a number of `-`s followed by the same number of `+`s through recursion + (?<del_ins> + - + \g<del_ins>? + \+ + ) + + # Runs end at the end of the string (the last line) or before a space (for an unchanged line) + (?= |\z) + }x.freeze + attr_accessor :old_line, :new_line, :offset def self.for_lines(lines) - local_edit_indexes = self.find_local_edits(lines) + changed_line_pairs = self.find_changed_line_pairs(lines) inline_diffs = [] - local_edit_indexes.each do |index| - old_index = index - new_index = index + 1 + changed_line_pairs.each do |old_index, new_index| old_line = lines[old_index] new_line = lines[new_index] @@ -51,18 +65,28 @@ module Gitlab private - def self.find_local_edits(lines) - line_prefixes = lines.map { |line| line.match(/\A([+-])/) ? $1 : ' ' } - joined_line_prefixes = " #{line_prefixes.join} " - - offset = 0 - local_edit_indexes = [] - while index = joined_line_prefixes.index(" -+ ", offset) - local_edit_indexes << index - offset = index + 1 + # Finds pairs of old/new line pairs that represent the same line that changed + def self.find_changed_line_pairs(lines) + # Prefixes of all diff lines, indicating their types + # For example: `" - + -+ ---+++ --+ -++"` + line_prefixes = lines.each_with_object("") { |line, s| s << line[0] }.gsub(/[^ +-]/, ' ') + + changed_line_pairs = [] + line_prefixes.scan(REGEX) do + # For `"---+++"`, `begin_index == 0`, `end_index == 6` + begin_index, end_index = Regexp.last_match.offset(:del_ins) + + # For `"---+++"`, `changed_line_count == 3` + changed_line_count = (end_index - begin_index) / 2 + + halfway_index = begin_index + changed_line_count + (begin_index...halfway_index).each do |i| + # For `"---+++"`, index 1 maps to 1 + 3 = 4 + changed_line_pairs << [i, i + changed_line_count] + end end - local_edit_indexes + changed_line_pairs end def longest_common_prefix(a, b) |