OK I've installed Grunt on the server and it is running "grunt watch".
demsley@orangeServer:/home/learndom/public_html/moodle/theme/curlew$ sudo grunt watch
Running "watch" task
Waiting...
...and I've updated the .js file in theme/curlew/amd/src and pushed it to the server and I get:
>> File "theme/curlew/amd/src/startup.js" changed.
Running "eslint:amd" (eslint) task
/home/learndom/public_html/moodle/theme/curlew/amd/src/startup.js
1:26 error Expected linebreaks to be 'LF' but found 'CRLF' linebreak-style
2:94 error Expected linebreaks to be 'LF' but found 'CRLF' linebreak-style
3:1 error Expected linebreaks to be 'LF' but found 'CRLF' linebreak-style
4:37 error Expected linebreaks to be 'LF' but found 'CRLF' linebreak-style
5:1 error Expected linebreaks to be 'LF' but found 'CRLF' linebreak-style
6:49 error Expected linebreaks to be 'LF' but found 'CRLF' linebreak-style
7:1 error Expected linebreaks to be 'LF' but found 'CRLF' linebreak-style
8:13 error Expected linebreaks to be 'LF' but found 'CRLF' linebreak-style
......
16:56 error Trailing spaces not allowed no-trailing-spaces
✖ 49 problems (49 errors, 0 warnings)
49 errors - not bad in 24 line script
Anyway
Many Thanks Davo and Paul