Trailing whitespace in processing instructions not preserved

[shunkica]

Describe the bug
Trailing whitespace in PI is not preserved.
One trailing whitespace is preserved if the PI does not have data.

To Reproduce
https://stackblitz.com/edit/js-xmldom-template-mcmkty?file=index.js

Expected behavior
The PI without data should have no trailing whitespace.
The trailing whitespace in PI with data should be preserved.
From DOM Level 1 spec:

Attributes
target
The target of this processing instruction. XML defines this as being the first token following the markup that begins the processing instruction.
data
The content of this processing instruction. This is from the first non white space character after the target to the character immediately preceding the ?>.

Runtime & Version:
xmldom version: 0.8.8

[karfau]

Thank you for reporting the issue.
I think the culprit is in the regular expression in https://github.com/xmldom/xmldom/blob/master/lib/sax.js#L611, which seems to drop whitespace before the closing symbols.

Here is the same section in the DOM Level 2 spec: https://www.w3.org/TR/DOM-Level-2-Core/#core-ID-1004215813

The XML spec is not really saying anything about the data, only about the target: https://www.w3.org/TR/2006/REC-xml11-20060816/#sec-pi

[karfau]

If I have to tackle it myself it will happen after I released 0.9.0, so there will be a patch for 0.8.x but not for 0.7.x

But if somebody else takes care of it before 0.9.0 is released 0.7.x will also be patched.