[SOLVED] Comparing XML equal files (except for whitespace) with xmlunit produces difference

Comparing XML equal files (except for whitespace) with xmlunit produces difference

Using xmlunit (version 2.6.0) to compare two XML files produces differences when they should be considered equal.

XML 1:

<top><a>one</a><b>two</b></top>

XML 2:

<top>
  <a>one</a>
  <b>two</b>
</top>

Java code: Source xmlSource1 = Input.fromFile(xmlFile1).build(); Source xmlSource2 = Input.fromFile(xmlFile2).build();

DefaultNodeMatcher nodeMatcher = new DefaultNodeMatcher(ElementSelectors.byNameAndText);

Diff d = DiffBuilder.compare(xmlSource1)
            .withNodeMatcher(nodeMatcher)
            .withTest(xmlSource2).build();
    Iterable<Difference> diffList = d.getDifferences();
    Iterator<Difference> iterator = diffList.iterator();
    while(iterator.hasNext()) {
        Difference next = iterator.next();
        log.info("Difference: " + next);
    }

Produces this output:

Difference: Expected child 'top' but was 'null' - comparing <top...> at /top[1] to <NULL> (DIFFERENT)
Difference: Expected child 'null' but was 'top' - comparing <NULL> to <top...> at /top[1] (DIFFERENT)

Question: why are they considered different? How can this comparison be done by ignoring whitespace differences? Ideally I would like d.hasDifferences() to be false.

Solution

Just ignore whitespaces (and comments) and perform check where similarities (see checkForSimilar()) are not included in the diff:

Diff d = DiffBuilder.compare(xmlSource1).withTest(xmlSource2)
 .checkForSimilar()
 .withNodeMatcher(nodeMatcher)
 .ignoreWhitespace()
 .ignoreComments()
 .build();