Format log output that is compatible with Intellij Idea <Click to see difference> diff viewer

gistfile1.groovy

// The example is in Groovy but this probably works for any kind of logging for an app/test running in IDEA
// The important part is the template:  "ComparisonFailure\nexpected:<{?}> but was:<{?}>"
// This works for multi-line values for each '?', which is why being able to use in-ide diff is so nice

def expected = ...
def actual = ...

// do your custom comparison, then if fails throw:

String msg = "ComparisonFailure\nexpected:<{${expected}}> but was:<{${actual}}>"
throw new AssertionError(msg)