for-promise

ForPromise-JS

ForPromise-JS is a lightweight utility for running asynchronous scripts in sequence — like a for, forEach, or while loop — but fully promise-based and with complete control over each iteration.

This module helps you run multiple asynchronous operations (Promises or callbacks) in an ordered, controlled flow within a single await call.

Instead of juggling multiple Promise instances inside regular loop structures (which can get messy or execute out of order), ForPromise-JS executes them sequentially, instantly, and cleanly — all inside one master Promise.

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✨ Key Features:

• Works with arrays, objects, numbers, and custom while conditions.
• Supports fn() and fn_error() callbacks.
• Allows break, forceResult, dontSendResult, and even nested async loops.
• Simple await-based usage — no need for external async/await handling inside the loop.

Perfect for replacing async logic inside for/forEach/while scripts — but safer and smarter.

📘 Usage Examples

🔁 Basic Loop: Number as Loop Count

Execute a loop a fixed number of times (like a traditional for loop).

// Import the module
import forPromise from 'for-promise';

// Loop will run 10 times
const dataCount = 10;

// Run the loop
await forPromise({ data: dataCount }, (index, result) => {
    
    // Display the current index
    console.log(`The index value is '${index}'.`);

    // Call result() to mark this iteration as complete
    result();

});

🧾 Looping Through Arrays or Objects

You can also loop through an array or object and handle asynchronous logic inside.

// Import the module
import forPromise from 'for-promise';
import fs from 'fs';

// Sample array
const data = [1, 2, 3, 4, 5];

// Loop through each index
await forPromise({ data }, (index, result, error) => {

    // Print current index and value
    console.log(`The index '${index}' has value '${data[index]}'.`);

    // Async operation: reading a directory
    fs.readdir('/some/folder/path', (err, files) => {

        if (!err) {
            // Success: mark the iteration as completed
            result();
        } else {
            // Error: interrupt the loop and reject the promise
            error(err);
        }

    });

});

➕ Adding Extra Loops Dynamically

Use extra() to add another loop from inside your main loop — perfect for nested async iterations!

// Import the module
import forPromise from 'for-promise';
import fs from 'fs';

// First dataset
const data1 = [1, 2, 3];
const data2 = [4, 5, 6];

// Outer loop
await forPromise({ data: data1 }, (index, result, error, extra) => {

    console.log(`Outer index '${index}' has value '${data1[index]}'.`);

    // Add a nested loop dynamically
    const extraLoop = extra({ data: data2 });

    // Run the nested loop
    extraLoop.run((index2, result2, error2) => {
        console.log(`  Inner index '${index2}' has value '${data2[index2]}'.`);

        fs.readdir('/another/folder', (err, files) => {
            if (!err) result2();
            else error2(err);
        });
    });

    // Continue outer loop
    result();

});

🔁 Execute a "Do While" Loop

Use the type: 'while' option to run a loop that repeats while a condition remains true — similar to a classic do...while structure.

// Import the module
import forPromise from 'for-promise';

// Data object to track the condition
const whileData = { count: 0 };

// Run the "do while" loop
await forPromise({

    // Set the loop type
    type: 'while',
    while: whileData,

    // Condition checker (must return true or false)
    checker: () => {
        return (whileData.count < 3);
    }

}, (done, error) => {

    // Loop body: will execute at least once
    console.log(`Do: ${whileData.count}`);

    // Update value
    whileData.count++;

    // Mark iteration as complete
    done();

});

💡 This script will print:

Do: 0  
Do: 1  
Do: 2  

🛑 Execute a "For Script" with Break FN

Use fn(true) inside the loop callback to force a break, just like a break statement in traditional for loops.

// Import the module
import forPromise from 'for-promise';

// Start the loop
await forPromise({
    data: [1, 2, 3]
}, (item, done) => {

    // Show the current item
    console.log(`Array with Force Break: ${item}`);

    // Break the loop immediately
    done(true);

});

💡 This will only execute once and stop the entire loop.

Array with Force Break: 1

You can use this when you need to exit early based on a certain condition, just like break in native loops.

🧠 Execute a "For Script" with forceResult, break, and dontSendResult

Use the fn() function with advanced options to control how the loop behaves and what result it returns.

// Import the module
import forPromise from 'for-promise';

// Example: Use filesystem
import fs from 'fs';
import path from 'path';

// Start the loop
await forPromise({
    data: [1, 2, 3]
}, (item, done, fail) => {

    // Async example: read a folder
    fs.readdir(path.join(__dirname, './folder'), (err, files) => {

        if (!err) {
            console.log(`Force Break used to read this data: ${item}`);
            console.log(files);

            // ✅ Mark this result as the final result and end all execution
            done({ forceResult: true });
        } else {
            // ❌ Stop execution and return the error
            fail(err);
        }

    });

    // 🛑 Stop further execution without returning a result
    done({ break: true, dontSendResult: true });

});

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🔍 Behavior Summary

• forceResult: true: Immediately ends the loop and returns this value as the final result.
• break: true: Stops the loop like a normal break.
• dontSendResult: true: Suppresses the current iteration result from being stored or returned.

💡 You can combine forceResult, break, and dontSendResult as needed to fully control the loop's execution and return behavior.

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🧠 This documentation was written with the help of AI assistance (ChatGPT by OpenAI) to ensure clarity, structure, and language accuracy.