Karma-runner coverage is reporting more than expected about stryker-js HOT 2 CLOSED

Found what the issue is. Take statement from circle.js for example:

var getCircumference = function(radius) {
  //Function to test multiple math mutations in a single function.
  return 2 * Math.PI * radius;
};

This gets reported as 2 statements:

1. from 1:1 to 4:2
2. from 3:2 to 3:30

Statement 1 is covered by literately every tests (the function declaration itself of course). I propose the following solution to fix this issue:

Think from the point of the mutation. Let's say the mutation is in statement 2 (for example: we mutate it to be return 2 / Math.PI * radius;). We first look for the smallest statement that is wrapping it. Next: we look to see which tests cover exactly that statement. That approach would even be less work, as we don't need to comb trough all statement maps.

from stryker-js.

See also #58

from stryker-js.