coverage-helpers

The prupose of this module is to provide helpers for node.js for instrumenting and generating lcov style reports.

API

instrument(buffer, "filename")

• buffer has to contain the code that you want to instrument.
• filename can be any string and will be used for the reporting.
• The return value is a buffer with the instrumented code

Executing the instrumented code will create and fill an object called _$Coverage. The contents will look like this:

{
    filename: {
        linenumber: timesExecuted
    }
}

Example

var _$Coverage = {
    'someJsFile.js': {
        0: 1,
        2: 1,
        5: 3,
        7: 0
    }
};

generateLcov(executedLines)

• exectuedLines is normaly just _$Coverage but you can pass anything that follows it's format.

• The return value is a string that follows the LCOV Data style. The output will look like this:

  SF:someJsFile
  DA:0,1
  DA:2,1
  DA:5,3
  DA:7,0
  end_of_record

You can visualize this by saving this to a file and running lcov -l coverage.dat also genhtml coverage.dat -o /tmp/report will be your friend.

combineResults(executedLines[, executedLines, …])

• exectuedLines is normaly just _$Coverage but you can pass anything that follows it's format.
• You can pass as many executedLines as you want to combine for example multiple clients.
• The return value is an object in the same format as _$Coverage but with all runs added up