RunKit + npm:

let SourceNode = require('source-map').SourceNode; function test(source) { let node = new SourceNode( null, null, source, [ 'prefix', new SourceNode(1, 0, source, 'code'), 'suffix', ] ); let { code, map } = node.toStringWithSourceMap(); console.log(map.toJSON(), code); } test("source"); test(null); test("");