How to use Node.js repl with file as input

Question

I wish to use a js file input as node.js repl, as if it was a command line code: node -e '<my code>', but with a <filename> instead of an inline code.

How can this be done as the file name as an input, without needing to use another file (such as fs.readFileSync(..))

Answer 1

One way is to use the REPL's .load command and Node's -i flag.

echo ".load test.js" | node -i

Outputs:

$ echo ".load test.js" | node -i 
Welcome to Node.js v12.8.1.
Type ".help" for more information.
> .load test.js
2 + 2;

4