Remove line breaks from start and end of string

I noticed that trim() does not remove new line characters from the start and end of a string, so I am trying to accomplish this with the following regex:

return str.replace(/^\s\n+|\s\n+$/g,'');

This does not remove the new lines, and I fear I am out of my depth here.

EDIT The string is being generated with ejs like so

go = ejs.render(data, { 
    locals: { 
        format() {
            // 
        }
    } 
});

And this is what go is, but with a few empty lines before. When I use go.trim() I still get the new lines before.

<?xml version="1.0"?>
<fo:root xmlns:fo="http://www.w3.org/1999/XSL/Format">
    <fo:layout-master-set>
        <fo:simple-page-master master-name="Out" page-width="8.5in" page-height="11in" margin-top="1in" margin-bottom="0.5in" margin-left="0.75in" margin-right="0.75in">
            <fo:region-body margin-top="1in" margin-bottom="0.25in"/>
            <fo:region-before extent="1in"/>
            <fo:region-after extent="0.25in"/>
            <fo:region-start extent="0in"/>
            <fo:region-end extent="0in"/>
        </fo:simple-page-master>
    </fo:layout-master-set>
    <fo:page-sequence master-reference="Out" initial-page-number="1" force-page-count="no-force">
        <fo:static-content flow-name="xsl-region-before">
            <fo:block font-size="14pt" text-align="center">ONLINE APPLICATION FOR SUMMARY ADVICE</fo:block>
            <fo:block font-size="13pt" font-weight="bold" text-align="center">Re:
                SDF, SDF
            </fo:block>

        </fo:static-content>

        <fo:flow flow-name="xsl-region-body" font="10pt Helvetica">

            .. removed this content

        </fo:flow>
    </fo:page-sequence>
</fo:root>

Try this:

str = str.replace(/^\s+|\s+$/g, '');

jsFiddle here.

String.trim() does in fact remove newlines (and all other whitespace). Maybe it didn't used to? It definitely does at the time of writing. From the linked documentation (emphasis added):

> The trim() method removes whitespace from both ends of a string. Whitespace in this context is all the whitespace characters (space, tab, no-break space, etc.) and all the line terminator characters (LF, CR, etc.).

---

If you want to trim all newlines plus other potential whitespace, you can use the following:

return str.trim();

If you want to only trim newlines, you can use a solution that targets newlines specifically.

/^\s+|\s+$/g should catch anything. Your current regex may have the problem that if your linebreaks contain \r characters they wouldn't be matched.

Try this:

str.split('\n').join('');