chore(utils): improve stripWhitespace utility

[mrazauskas]

Types of changes

• Bug fix (a non-breaking change which fixes an issue)
• New feature (a non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Description

This is a minor fix. I was playing with plugin templates and found that stripWhitespace utility is not removing empty lines if these appear at the beginning of a file. For instance, empty lines will be left if a template begins like this one:

<% if (options.debug) { %>
import { debug } from '<%= options.import.path %>'
<% } %>
// rest of the file

A regexp was added to remove empty lines if they appear at the beginning of a file. g, global search flag seemed to be unnecessary, because globally there is just one beginning (or end) of a string. Or I missed something important? g is not included in the new regexp. For consistency I removed it in the regexp which was targeting the end of a string. (Alternatively g flag could be added to both.)

Test

After the change, the expect with '\n\n\n\f\r\f}' string was failing. I improved this and other tests by adding foo before (or bar after) \n as if these samples are taken from the middle of a string. Also after strip multiple blank lines regexp there must be only double \n\ns left in the string, so two last expects simply checks double \n\ns.

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly. (PR: #)
• I have added tests to cover my changes (if not applicable, please state why)
• All new and existing tests are passing.

[pi0]

Thanks!