db.auth(username, password) results in:

 
db.auth('root', 'somepasssword')
 [MongoParseError:|#] URI malformed, cannot be parsed
at parseConnectionString (/home/addaleax/src/compass/node_modules/@mongodb-js/compass-shell/lib/index.js:269831:21) at connect (/home/addaleax/src/compass/node_modules/@mongodb-js/compass-shell/lib/index.js:139038:3) at /home/addaleax/src/compass/node_modules/@mongodb-js/compass-shell/lib/index.js:62583:5 at maybePromise (/home/addaleax/src/compass/node_modules/@mongodb-js/compass-shell/lib/index.js:772:3) at MongoClient.connect (/home/addaleax/src/compass/node_modules/@mongodb-js/compass-shell/lib/index.js:62579:10) at Function.MongoClient.connect (/home/addaleax/src/compass/node_modules/@mongodb-js/compass-shell/lib/index.js:62802:22) at CompassServiceProvider._callee18$ (/home/addaleax/src/compass/node_modules/@mongodb-js/compass-shell/lib/index.js:131963:46) at tryCatch (/home/addaleax/src/compass/node_modules/@mongodb-js/compass-shell/lib/index.js:142634:40) at Generator.invoke [as _invoke] (/home/addaleax/src/compass/node_modules/@mongodb-js/compass-shell/lib/index.js:142864:22) at Generator.next (/home/addaleax/src/compass/node_modules/@mongodb-js/compass-shell/lib/index.js:142689:21)