This is snagged from diff/lcs/ldiff.rb (which is a commandline tool)
# File lib/spec/expectations/differs/default.rb, line 20
def diff_as_string(data_new, data_old)
data_old = data_old.split(/\n/).map! { |e| e.chomp }
data_new = data_new.split(/\n/).map! { |e| e.chomp }
output = ""
diffs = Diff::LCS.diff(data_old, data_new)
return output if diffs.empty?
oldhunk = hunk = nil
file_length_difference = 0
diffs.each do |piece|
begin
hunk = Diff::LCS::Hunk.new(data_old, data_new, piece, context_lines,
file_length_difference)
file_length_difference = hunk.file_length_difference
next unless oldhunk
# Hunks may overlap, which is why we need to be careful when our
# diff includes lines of context. Otherwise, we might print
# redundant lines.
if (context_lines > 0) and hunk.overlaps?(oldhunk)
hunk.unshift(oldhunk)
else
output << oldhunk.diff(format)
end
ensure
oldhunk = hunk
output << "\n"
end
end
#Handle the last remaining hunk
output << oldhunk.diff(format) << "\n"
end
