node-jscover: nodejs version of JSCover

[yiminghe]

Hi:
This library is great, especially the interesting front-end part. But I prefer a javascript version of coverage tool to instrument itself. So I reimplement your algorithm in nodejs at: https://github.com/yiminghe/node-jscover.

However, there are two points i do not understand:

1. what does getLinePosition of BranchInstrumentor.java mean? I simply return ast node's column information, but it seems node-jscover is not always generating the same code as JSCover on this aspect.
2. condition expression is not instrumented using JSCover, for example:

var x= y? 1:2;

after instrumented by JSCover

var x = y?1:2;

after instrumented by node-jscover

var x = visited(y)?1:2;

[tntim96]

what does getLinePosition of BranchInstrumentor.java mean

It returns the number of characters into the line that the branch condition starts on. It is currently unused in JSCover.

condition expression is not instrumented using JSCover

Sure it is. Take a look at shouldWrapTernaryCondition in BranchInstrumentorIntegrationTest and the branch instrumentation section of the manual

[yiminghe]

It returns the number of characters into the line that the branch condition starts on. It is currently unused in JSCover.

getLinePosition is same with column in esprima (http://esprima.org/demo/parse.html)? but i discovered getLinePosition is not always same as column.

Sure it is. Take a look at shouldWrapTernaryCondition in BranchInstrumentorIntegrationTest and the branch instrumentation section of the manual

I mean JSCover does not instrument, maybe a bug

var x = y?1:2;

not

var x=y>0?1:2;

[tntim96]

I mean JSCover does not instrument (var x = y?1:2;), maybe a bug

You're right. I've fixed it and a couple of other similar problems - can you re-test? You can rebuild from trunk or download from here.

i discovered getLinePosition is not always same as column

That's why I'm not using it ;)