From install to first LIFO run.

Install and import

easy-stack has no runtime dependencies. Node.js 22.13 or newer can use native ESM or CommonJS; both loaders resolve the same synchronous stack.js implementation.

npm install easy-stack

// Native ESM
import Stack from 'easy-stack';

// CommonJS
const Stack = require('easy-stack');

Both imports return the same constructor identity. The package uses Node's native ESM/CommonJS interoperability without a compiler, bundler, or duplicate runtime file.

easy-stack works with bundlers and without a bundler. Bundlers resolve easy-stack normally; native browser ESM uses an import map before the module script, with no build or transpilation step. The browser guide shows the complete normal npm-layout map and HTTP(S) serving requirements.

Run a first stack

Disable auto-run while loading the example so the complete batch is present before execution starts. The last callback added executes first.

import Stack from 'easy-stack';

const stack = new Stack();
const order = [];
stack.autoRun = false;

stack.add(
    function first() {
        order.push('first');
        this.next();
    },
    function second() {
        order.push('second');
        this.next();
    },
    function third() {
        order.push('third');
        this.next();
    }
);

stack.next();
console.log(order); // ['third', 'second', 'first']

Understand the cooperative model

Auto-run controls only the initial start. Once a task is active, the stack waits until that task calls next(). This makes a task a deliberate hand-off point for synchronous work, timers, events, or network responses.

• add() places every supplied function on top in argument order.
• The last supplied function is selected first.
• A task may pause simply by returning without calling next().
• Resume later by calling stack.next() from the appropriate completion signal.
• Set stop = true to gate selection without discarding pending functions.