the content is too long, How to display the complete content in console.log()?

Run it through JSON.stringify so you are logging a single string and not a complex data structure.

as say here How can I get the full object in Node.js's console.log(), rather than '[Object]'?

you can convert your element (object or array) directly in json by using

console.log('my elem : %j', myObject);

or if you want more display option, you can use util.inspect

const util = require('util')
console.log(util.inspect(myObject, {showHidden: false, depth: null, colors: true}))

You can use

 console.dir(myArry, {'maxArrayLength': null});

The console method log() displays the toString representation of any object passed to it. The Console method dir() displays an interactive list of the properties of the specified JavaScript object

Link for reference : Dumping whole array: console.log and console.dir output "... NUM more items]"

For larger arrays, this works nicely:

myLargeArray.forEach( element => console.log( JSON.stringify( element ) ) );