Detect shebangs absolutely to node, wrap those too

[isaacs]

When there's a program that doesn't match one of the other criteria, read its contents, and if it's a shebang to node, then wrap it.

This lets nyc wrap npm when npm is a shebang to an absolute path to Node.

Closes #12

[bcoe]

this doesn't quite do the trick, because the npm bin is doing something quite wonky:

#!/bin/sh
// 2>/dev/null; exec "`dirname "$0"`/node" "$0" "$@"

looks like it's dynamically generating the absolute path to node, I used the following shim to solve the problem:

https://github.com/tapjs/spawn-wrap/pull/14/files#diff-168726dbe96b3ce427e7fedce31bb0bcR151

it uses which in a similar way to your approach, and is more generic than @addaleax's initial fact finding mission.

[addaleax]

Yup, this hack that the Node.js people install in the npm executable is one of the reasons I decided to try the special check for "npm" instead of shebang matching.

+1 for using which, I thought of that but didn’t dare add a dependency here. 😄

[bcoe]

@isaacs you should be able to rebase with master now and appveyor will pass. I turned off node@0.10.x which has never worked. I can boot Windows 7 at some point and dig into this, I think it's mostly exit-code edge-cases.