Readable Textarea Expander

Expands small textareas to improve readability and editing comfort on common websites.

This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require https://update.greasyfork.org/scripts/570704/1780717/Readable%20Textarea%20Expander.js

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Wrap lines

// ==UserScript==
// @name         Readable Textarea Expander
// @namespace    https://example.com/userscripts
// @version      1.0.0
// @description  Expands small textareas to improve readability and editing comfort on common websites.
// @match        *://*/*
// @grant        none
// ==/UserScript==

(function () {
    'use strict';

    // Minimum height for textareas that are too small
    const MIN_HEIGHT = 220;

    // Apply better sizing to a textarea
    function improveTextarea(textarea) {
        if (!(textarea instanceof HTMLTextAreaElement)) {
            return;
        }

        // Avoid processing the same textarea multiple times
        if (textarea.dataset.expanderApplied === 'true') {
            return;
        }
        textarea.dataset.expanderApplied = 'true';

        const computedStyle = window.getComputedStyle(textarea);
        const currentHeight = parseFloat(computedStyle.height) || textarea.offsetHeight;

        if (currentHeight < MIN_HEIGHT) {
            textarea.style.minHeight = `${MIN_HEIGHT}px`;
        }

        textarea.style.resize = 'vertical';
        textarea.style.lineHeight = '1.5';
        textarea.style.padding = '10px';
        textarea.style.boxSizing = 'border-box';
    }

    // Process all existing textareas
    function processPage() {
        const textareas = document.querySelectorAll('textarea');
        textareas.forEach(improveTextarea);
    }

    // Watch for dynamically added textareas
    const observer = new MutationObserver(() => {
        processPage();
    });

    observer.observe(document.documentElement, {
        childList: true,
        subtree: true
    });

    // Run once on load
    processPage();
})();