README.md

## istanbul-lib-instrument

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Istanbul instrumenter library.

Version 1.1.x now implements instrumentation using `Babel`. The implementation is inspired
by prior art by @dtinth as demonstrated in the `__coverage__` babel plugin.

It provides 2 "modes" of instrumentation.

-   The old API that is mostly unchanged (except for incompatibilities noted) and
    performs the instrumentation using babel as a library.

-   A `programVisitor` function for the Babel AST that can be used by a Babel plugin
    to emit instrumentation for ES6 code directly without any source map
    processing. This is the preferred path for babel users. The Babel plugin is
    called `babel-plugin-istanbul`.

Incompatibilities and changes to instrumentation behavior can be found in
[v0-changes.md](v0-changes.md).