scala triple引用字符串的不可预知的行为

Question

I'm using junit in scala to compare string output from my scala code. Something like :

val expected = """<Destination id="0" type="EMAIL">
<Address>
    me@test.com
</Address>
<TimeZone>
    US/Eastern
</TimeZone>    
<Message>      
</Message>
</Destination>
"""
 val actual = getTextToLog()
 info(" actual = " + actual)
 assert(expected == actual)

The issue is that for some strings, assertions like :

assert(expected == actual)

work and for some they strings they dont. Even when I copy actual (logged to Eclipse console) from Eclipse console and paste it into expected just to be sure , the assertion still fails.

What am I missing?

Answer 1

OK, since this turns out to be a whitespace issues, you should sanitise the two strings before comparing them. Look at the RichString methods like .lines , for example, which might let you create a line-ending or whitespace-agnostic comparison method.

Here is one naive way of doing this with implicit conversions:

import scala.language.implicitConversions
object WhiteSpace {
  implicit def strToWhiteSpace(s: String) = new WhiteSpace(s)
}

class WhiteSpace(val s: String) {
  def `~==` (other: String) = s.lines.toList == other.lines.toList
}

which allows

import WhiteSpace._
assert(expected ~== actual)

Or you could extend the appropriate jutils class to add an agnostic version of assertEquals .

Note that this comparison deconstructs both strings in the same way. This is much safer than sending one of them on a round-trip conversion.

Whitespace/crlf issues are so common that there's no point fighting it by trying to stop the mismatches; just do agnostic comparisons.