Different Ways to Call a Node Function From the Command Line

index.md

Different Ways to Call a Node Function From the Command Line

Separate Initializer in Its Own File

Pros:

• Main logic file can contain a variety of different functions/processes that don't have to pertain to the function that's being run.
• Function can easily be called from other scripts, but also directly from the command line.

Cons:

• Requires extra file.

util.js

export function doThing() {
  console.log("I did a thing");
}

thing.js

import { thing } from './util.js';
thing();

$ node thing.js

---

Self-Executing Logic

Pros:

• File is essentially the function. Self-contained execution scope is minimal and simple for command line usage.

Cons:

• Requires dynamic import if you really want to call it from another module rather than the command line.
• Can't reasonably ingest arguments or return values.

thing.js

console.log("I did a thing");

$ node thing.js

---

Single File with Initializer Function

Pros:

• No "dangling" code. If the file contains a lot of complicated logic, then the "init"/"constructor" initializer function identifies an entry point to the logic.
• Provides an additional scope to variables that may need to be private within the file.

Cons:

• Requires dynamic import if you really want to call it from another module rather than the command line.
• Can't reasonably ingest arguments or return values.
• Might introduce an unnecessary scope.

thing.js

function init() {
  console.log("I did a thing");
}

init();

$ node thing.js