Istanbul: Using babel compiler with mocha

[jladuval]

Hi there, just wondering if it's possible to use a babel compiler with mocha and still have istanbul generate coverage statistics. At the moment this is my test script

./node_modules/.bin/istanbul cover ./node_modules/.bin/_mocha --compilers js:babel/register --recursive specs

But i get the error

Error: cannot resolve path (or pattern) 'js:babel/register'

Tests run fine if I remove istanbul from the command. Any ideas?

[davglass]

You should use the -- separator to tell istanbul to pass the remaining args to mocha:

https://github.com/gotwarlost/istanbul#the-cover-command

[iamstarkov]

Yep, like this: istanbul cover _mocha -- --require babel/register

[niln1]

@davglass @iamstarkov I cannot get istanbul to produce coverage report on source file instead of the babeled file. any Idea??

[iamstarkov]

@nilveryawesome its impossible, try isparta!!!11 or ask on stackoverflow. Is it helpful??

[xjamundx]

Struggling with this as well, but I can share some things that do and do not work.

Does not work

Using -r babel-register with istanbul gives the dreaded "No coverage information was collected," error likely because istanbul's require hook is wiped out by babel's require hook .

node ./node_modules/istanbul/lib/cli.js cover ./node_modules/mocha/bin/_mocha — -r babel-register -R dot --recursive tests/unit/lib

Does not work

Using --compilers with the js:babel-register does the exact same thing as above. We're left with the No coverage information was collection message.

./node_modules/istanbul/lib/cli.js cover ./node_modules/mocha/bin/_mocha -- --recursive tests/unit/lib --compilers js:babel-register

Almost Works

This command shows a coverage report, but shows incorrect coverage numbers. Further investigation shows the hooks are in place properly for coverage, but mocha still chokes on the es6 code and fails.

babel-node ./node_modules/istanbul/lib/cli.js cover ./node_modules/mocha/bin/_mocha -- -R dot --recursive tests/unit/lib

Almost Works

Swapping istanbul for isparta however seems to cause the coverage report to die pre-maturely without an error message.

node ./node_modules/.bin/isparta cover ./node_modules/mocha/bin/_mocha -- -R dot --recursive tests/unit/

Works

Calling isparta with babel-node solves the problem of coverage not being reported and failing with unknown syntax.

babel-node ./node_modules/.bin/isparta cover ./node_modules/mocha/bin/_mocha -- -R dot --recursive tests/unit/

[frederickfogerty]

@jladuval did you find a solution?

[brunops]

This seems to work for me: ./node_modules/istanbul/lib/cli.js cover --dir=./coverage/unit ./node_modules/mocha/bin/_mocha -- --recursive test/unit --compilers js:babel/register -R spec

ps: --dir= is optional

[xjamundx]

@brunops sorry dude, added that to my does not work list above. Same issue as before. Somehow the babel compiler over-rides the istanbul compiler and it doesn't instrument anything. I wonder if this is a babel6 thing.

[brunops]

Maybe. I'm using babel 5.8.23, istanbul 0.3.22 and mocha 3.2.4.

[jladuval]

Sorry guys just got alerted that this is still open! The -- fix worked fine, thanks for everyones help