artberri/rollup-plugin-istanbul

import { createFilter } from "@rollup/pluginutils"
import istanbul from "istanbul-lib-instrument"

function addDefaultOptions(options) {
    return Object.assign(
        {
            esModules: true,
            compact: true,
            produceSourceMap: true,
            autoWrap: true,
            preserveComments: true,
        },
        options,
    )
}

export default function (options = {}) {
    const filter = createFilter(options.include, options.exclude)

    return {
        name: "istanbul",
        transform(code, id) {
            if (!filter(id)) {
                return
            }

            const instrumenterConfig = addDefaultOptions(options.instrumenterConfig)

            const instrumenter = new (
                options.instrumenter || istanbul
            ).createInstrumenter(instrumenterConfig)

            const { version, sources, sourcesContent, names, mappings, file } =
                this.getCombinedSourcemap()

            const instrumentedCode = instrumenter.instrumentSync(code, id, {
                version,
                sources,
                sourcesContent,
                names,
                mappings,
                file,
            })

            return { code: instrumentedCode, map: instrumenter.lastSourceMap() }
        },
    }
}