Returns a diff between
exp and act. If there is no known diff command or if it doesn’t
make sense to diff the output
(single line, short output), then it simply returns a basic comparison
between the two.
# File lib/minitest/unit.rb, line 104
def diff exp, act
require "tempfile"
expect = mu_pp_for_diff exp
butwas = mu_pp_for_diff act
result = nil
need_to_diff =
MiniTest::Assertions.diff &&
(expect.include?("\n") ||
butwas.include?("\n") ||
expect.size > 30 ||
butwas.size > 30 ||
expect == butwas)
return "Expected: #{mu_pp exp}\n Actual: #{mu_pp act}" unless
need_to_diff
Tempfile.open("expect") do |a|
a.puts expect
a.flush
Tempfile.open("butwas") do |b|
b.puts butwas
b.flush
result = `#{MiniTest::Assertions.diff} #{a.path} #{b.path}`
result.sub!(/^\-\-\- .+/, "--- expected")
result.sub!(/^\+\+\+ .+/, "+++ actual")
if result.empty? then
klass = exp.class
result = [
"No visible difference.",
"You should look at your implementation of #{klass}#==.",
expect
].join "\n"
end
end
end
result
end