.coverrc

{
    "formatter": "cli",
    "ignore": ".coverignore",

    "prefix": "coveragefile_",              // Prefix for coverage data files
    "dataDirectory": ".coverage_data",      // Directory to put coverage files in

    "debugDirectory": ".coverage_debug",    // Directory to put instrumented files in

    "modules": false,                       // Whether or not to cover node_modules directory

    // Formatter-specific info
    "html" : {
        "directory": "cover_html",          // Directory to write HTML files too
        "generateIndex": true               // Whether to generate an index.html file
    },

    "json": {
    }
}