Can I use istanbul to instrument for mocha html-cov

Question

I'm trying to use istanbul instrument output to mocha -R html-cov but cannot get it to work.

My test script is:

test:
  post:
    - node_modules/.bin/istanbul cover node_modules/.bin/_mocha -dir $CIRCLE_ARTIFACTS -- -u exports -R spec
    - node_modules/.bin/istanbul instrument . -o lib-cov
    - cp package.json lib-cov/ # needs to be copied manually
    - MY_LIB_COV=1 node_modules/.bin/mocha -R html-cov > $CIRCLE_ARTIFACTS/coverage.html

My tests have the following switch:

var mylib = process.env.MY_LIB_COV ? require('../lib-cov') : require('../');

Istanbul is giving me a good output at lcov-report/index.html.
Mocha's html-cov is giving me '0% coverage 0 SLOC' at coverage.html

Istanbul's lcov report is ugly. I want to use the pretty mocha -R html-cov report.

All the examples I've found use jscoverage. Do I have to use jscoverage? Am I missing a trick?

Answer 1

Yes, mocha's html-cov only reports on what jscoverage provides. See https://mochajs.org/#reporters