diff --git a/app/assets/javascripts/lib/utils/sticky.js b/app/assets/javascripts/lib/utils/sticky.js index 283c0ec0410..64db42701ce 100644 --- a/app/assets/javascripts/lib/utils/sticky.js +++ b/app/assets/javascripts/lib/utils/sticky.js @@ -1,14 +1,34 @@ -export const isSticky = (el, scrollY, stickyTop) => { +export const createPlaceholder = () => { + const placeholder = document.createElement('div'); + placeholder.classList.add('sticky-placeholder'); + + return placeholder; +}; + +export const isSticky = (el, scrollY, stickyTop, insertPlaceholder) => { const top = Math.floor(el.offsetTop - scrollY); - if (top <= stickyTop) { + if (top <= stickyTop && !el.classList.contains('is-stuck')) { + const placeholder = insertPlaceholder ? createPlaceholder() : null; + const heightBefore = el.offsetHeight; + el.classList.add('is-stuck'); - } else { + + if (insertPlaceholder) { + el.parentNode.insertBefore(placeholder, el.nextElementSibling); + + placeholder.style.height = `${heightBefore - el.offsetHeight}px`; + } + } else if (top > stickyTop && el.classList.contains('is-stuck')) { el.classList.remove('is-stuck'); + + if (insertPlaceholder && el.nextElementSibling && el.nextElementSibling.classList.contains('sticky-placeholder')) { + el.nextElementSibling.remove(); + } } }; -export default (el) => { +export default (el, insertPlaceholder = true) => { if (!el) return; const computedStyle = window.getComputedStyle(el); @@ -17,7 +37,7 @@ export default (el) => { const stickyTop = parseInt(computedStyle.top, 10); - document.addEventListener('scroll', () => isSticky(el, window.scrollY, stickyTop), { + document.addEventListener('scroll', () => isSticky(el, window.scrollY, stickyTop, insertPlaceholder), { passive: true, }); }; diff --git a/app/assets/stylesheets/pages/diff.scss b/app/assets/stylesheets/pages/diff.scss index 951580ea1fe..ed9d5e98467 100644 --- a/app/assets/stylesheets/pages/diff.scss +++ b/app/assets/stylesheets/pages/diff.scss @@ -451,7 +451,7 @@ } .files { - margin-top: -1px; + margin-top: 1px; .diff-file:last-child { margin-bottom: 0; @@ -586,11 +586,6 @@ top: 76px; } - + .files, - + .alert { - margin-top: 1px; - } - &:not(.is-stuck) .diff-stats-additions-deletions-collapsed { display: none; } @@ -605,11 +600,6 @@ .inline-parallel-buttons { display: none; } - - + .files, - + .alert { - margin-top: 32px; - } } } } diff --git a/app/assets/stylesheets/test.scss b/app/assets/stylesheets/test.scss index 7d9f3da79c5..06733b7f1a9 100644 --- a/app/assets/stylesheets/test.scss +++ b/app/assets/stylesheets/test.scss @@ -15,3 +15,9 @@ -ms-animation: none !important; animation: none !important; } + +// Disable sticky changes bar for tests +.diff-files-changed { + position: relative !important; + top: 0 !important; +} diff --git a/spec/javascripts/lib/utils/sticky_spec.js b/spec/javascripts/lib/utils/sticky_spec.js index c3ee3ef9825..b87c836654d 100644 --- a/spec/javascripts/lib/utils/sticky_spec.js +++ b/spec/javascripts/lib/utils/sticky_spec.js @@ -1,52 +1,79 @@ import { isSticky } from '~/lib/utils/sticky'; describe('sticky', () => { - const el = { - offsetTop: 0, - classList: {}, - }; + let el; beforeEach(() => { - el.offsetTop = 0; - el.classList.add = jasmine.createSpy('spy'); - el.classList.remove = jasmine.createSpy('spy'); + document.body.innerHTML += ` +
+
+
+ `; + + el = document.getElementById('js-sticky'); }); - describe('classList.remove', () => { - it('does not call classList.remove when stuck', () => { - isSticky(el, 0, 0); + afterEach(() => { + el.parentNode.remove(); + }); + + describe('when stuck', () => { + it('does not remove is-stuck class', () => { + isSticky(el, 0, el.offsetTop); + isSticky(el, 0, el.offsetTop); expect( - el.classList.remove, - ).not.toHaveBeenCalled(); + el.classList.contains('is-stuck'), + ).toBeTruthy(); }); - it('calls classList.remove when not stuck', () => { - el.offsetTop = 10; + it('adds is-stuck class', () => { + isSticky(el, 0, el.offsetTop); + + expect( + el.classList.contains('is-stuck'), + ).toBeTruthy(); + }); + + it('inserts placeholder element', () => { + isSticky(el, 0, el.offsetTop, true); + + expect( + document.querySelector('.sticky-placeholder'), + ).not.toBeNull(); + }); + }); + + describe('when not stuck', () => { + it('removes is-stuck class', () => { + spyOn(el.classList, 'remove').and.callThrough(); + + isSticky(el, 0, el.offsetTop); isSticky(el, 0, 0); expect( el.classList.remove, ).toHaveBeenCalledWith('is-stuck'); + expect( + el.classList.contains('is-stuck'), + ).toBeFalsy(); }); - }); - describe('classList.add', () => { - it('calls classList.add when stuck', () => { + it('does not add is-stuck class', () => { isSticky(el, 0, 0); expect( - el.classList.add, - ).toHaveBeenCalledWith('is-stuck'); + el.classList.contains('is-stuck'), + ).toBeFalsy(); }); - it('does not call classList.add when not stuck', () => { - el.offsetTop = 10; - isSticky(el, 0, 0); + it('removes placeholder', () => { + isSticky(el, 0, el.offsetTop, true); + isSticky(el, 0, 0, true); expect( - el.classList.add, - ).not.toHaveBeenCalled(); + document.querySelector('.sticky-placeholder'), + ).toBeNull(); }); }); });