BUG: error on combining reports

[osher]

I think it has to do with one of my files has zero branches.

$ istanbul report --root ./coverage --dir ./coverage/combined --format html

> cwt-oapi-util@0.2.0 cover-combine-reports /home/developer/cwt-oapi-util
> istanbul report --root ./coverage --dir ./coverage/combined --format html

/home/developer/cwt-oapi-util/node_modules/istanbul/lib/object-utils.js:247
            for (i = 0; i < retArray.length; i += 1) {
                                    ^

TypeError: Cannot read property 'length' of undefined
    at /home/developer/cwt-oapi-util/node_modules/istanbul/lib/object-utils.js:247:37
    at Array.forEach (native)
    at Object.mergeFileCoverage (/home/developer/cwt-oapi-util/node_modules/istanbul/lib/object-utils.js:244:31)
    at /home/developer/cwt-oapi-util/node_modules/istanbul/lib/collector.js:71:44
    at Array.forEach (native)
    at Object.add (/home/developer/cwt-oapi-util/node_modules/istanbul/lib/collector.js:68:31)
    at /home/developer/cwt-oapi-util/node_modules/istanbul/lib/command/report.js:111:27
    at Array.forEach (native)
    at /home/developer/cwt-oapi-util/node_modules/istanbul/lib/command/report.js:109:19
    at /home/developer/cwt-oapi-util/node_modules/istanbul/lib/util/file-matcher.js:39:20

/home/developer/cwt-oapi-util/node_modules/istanbul/lib/object-utils.js:247:

        Object.keys(second.b).forEach(function (k) {
            var retArray = ret.b[k],
                secondArray = second.b[k];
            for (i = 0; i < retArray.length; i += 1) {   //<---- the line that falls
                retArray[i] += secondArray[i];
            }
        });

So I tried to hack it:

        Object.keys(second.b).forEach(function (k) {
            var retArray = ret.b[k] || [],            // <---- proposed fix
                secondArray = second.b[k];
            for (i = 0; i < retArray.length; i += 1) {   
                retArray[i] += secondArray[i];
            }
        });

then I got:

$ istanbul report --root ./coverage --dir ./coverage/combined --format html

/home/developer/cwt-oapi-util/node_modules/istanbul/lib/object-utils.js:59
                var line = statementMap[st].start.line,
                                           ^

TypeError: Cannot read property 'start' of undefined
    at /home/developer/cwt-oapi-util/node_modules/istanbul/lib/object-utils.js:59:44
    at Array.forEach (native)
    at Object.addDerivedInfoForFile (/home/developer/cwt-oapi-util/node_modules/istanbul/lib/object-utils.js:58:37)
    at Object.fileCoverageFor (/home/developer/cwt-oapi-util/node_modules/istanbul/lib/collector.js:94:15)
    at /home/developer/cwt-oapi-util/node_modules/istanbul/lib/report/html.js:558:90
    at Array.forEach (native)
    at HtmlReport.writeReport (/home/developer/cwt-oapi-util/node_modules/istanbul/lib/report/html.js:557:27)
    at /home/developer/cwt-oapi-util/node_modules/istanbul/lib/reporter.js:93:20
    at Array.forEach (native)
    at Object.write (/home/developer/cwt-oapi-util/node_modules/istanbul/lib/reporter.js:87:30)

that's a little too much for me ATM... Can anybody help?

[fgaleano]

@osher Were you able to ever figure this out? I'm having a similar problem now. Basically statementMap is empty so it's failing at the same line it was failing for you. How did you move forward?

[osher]

sorry, guys, I moved on to a different place. I don't even remember what was the work around 😛

[MikeyBurkman]

I just randomly ran into this on Google. For me, deleting the coverage folder and re-running seems to work pretty well.