istanbul-lib-instrument

Instrumenting Code

This feature allows you to instrument JavaScript code. The `createInstrumenter` function creates an instrumenter instance, which can then be used to instrument code synchronously using the `instrumentSync` method. The instrumented code will include additional statements to track execution.

const { createInstrumenter } = require('istanbul-lib-instrument');
const instrumenter = createInstrumenter();
const originalCode = 'function add(a, b) { return a + b; }';
const instrumentedCode = instrumenter.instrumentSync(originalCode, 'filename.js');
console.log(instrumentedCode);

Generating Coverage Maps

This feature allows you to generate a coverage map for the instrumented code. After instrumenting the code, you can call the `lastFileCoverage` method to get a coverage map, which provides detailed information about which parts of the code were executed.

const { createInstrumenter } = require('istanbul-lib-instrument');
const instrumenter = createInstrumenter();
const originalCode = 'function add(a, b) { return a + b; }';
instrumenter.instrumentSync(originalCode, 'filename.js');
const coverageMap = instrumenter.lastFileCoverage();
console.log(coverageMap);