I would like to console.log a message and return an empty array if I try to read a file that doesn't exist. The getAllNotes function fires effective and the error is definitely thrown no such file or directory, open 'notes.json'.
However, why is the error thrown if I didn't specify throw err in my if statement? Secondly why doesn't my console.log message get outputted and the empty array not returned?
var getAllNotes = () => {
console.log("MADE IT TO GET ALL NOTES")
var notesArray = fs.readFileSync('notes.json', (err, data) => {
if (err) {
console.log("There are no notes to display");
return [];
} else {
console.log("DATA",data)
console.log("MADE IT TO PARSE")
return JSON.parse(data);
}
});
console.log("INSIDE GET ALL NOTES", notesArray)
};
fs.readFileSync is a blocking call and doesn't take a callback in the same way that fs.readFile does. It simply returns the contents of the file, see the below example:
var fs = require('fs');
var date = fs.readFileSync('myfile', 'utf8');
console.log(data);
When I ran your example an exception is thrown because you are providing a callback function where it is expecting a string or object for the options parameter.
You can do a blocking call with fs.existsSync(path) to check if the file exists before trying to read it.
Alternatively you can use the non-blocking version of the readFile and provide the callback as you were trying to do.