Remove JQ in 2025 and use native JS

Objective. Reduce jQuery dependency to decrease bundle size and technical debt, improve runtime performance and maintainability by adopting native JavaScript.

Key benefits

Smaller bundle → faster page loads.

Fewer external dependencies → reduced security/compatibility risk.

Modern browser APIs (Fetch, classList, closest, querySelector / querySelectorAll, Promise / async-await) cover most use cases.

Easier debugging and clearer codebase for the engineering team.

Migration roadmap

Code audit — locate all jQuery usage (DOM, AJAX, animations, third-party plugins).

Prioritize — classify by risk: business-critical vs low-impact scripts.

Build small internal utils — DOM helpers and an AJAX wrapper to avoid adding heavy dependencies.

Polyfills — include only if required by your supported browsers. In 2025, IE support is typically unnecessary—align with your browser support policy.

Incremental refactor — migrate files one-by-one, add unit/integration tests, use feature flags or phased deploys.

Testing — run E2E and regression tests across targeted browsers/devices.

Remove jQuery — once refactor and tests pass, remove package and rebuild.

Update docs & reviews — refresh internal guidelines and enforce a native-JS review checklist.

Practical replacements (quick snippets)

DOM ready: document.addEventListener('DOMContentLoaded', ...)

Selectors/classes: document.querySelector() + .classList

Delegated events: parent.addEventListener('click', e => { const it = e.target.closest('.item'); ... })

AJAX: replace $.ajax with fetch / async-await.

Risks & mitigations

jQuery-dependent plugins — replace, wrap, or isolate.

Insufficient tests — add coverage before removing jQuery.

Team adoption — provide training, coding standards, and PR templates.

`

DOM ready:

// jQuery $(document).ready(() => { /* init */ });

// Native document.addEventListener('DOMContentLoaded', () => { /* init */ });

Селекторы и классы:

// jQuery const $el = $('.btn'); $el.addClass('is-active');

// Native const el = document.querySelector('.btn'); el.classList.add('is-active');

Делегирование событий:

// jQuery $(parent).on('click', '.item', handler);

// Native parent.addEventListener('click', (e) => { const item = e.target.closest('.item'); if (item && parent.contains(item)) handler.call(item, e); });

AJAX → Fetch:

// jQuery $.ajax({ url: '/api', method: 'POST', data: { a:1 } }) .done(res => ...) .fail(err => ...);

// Native fetch('/api', { method: 'POST', body: JSON.stringify({ a:1 }), headers: {'Content-Type':'application/json'} }) .then(r => r.json()) .then(res => ...) .catch(err => ...); `