From dfa017adc382c63766cd5d021bdc8f6ad1b04932 Mon Sep 17 00:00:00 2001
From: ysds <ysds.code@gmail.com>
Date: Wed, 4 Mar 2020 23:51:15 +0900
Subject: [PATCH] Always modal scroll top to 0

---
 js/src/modal.js             |  6 ++----
 js/tests/unit/modal.spec.js | 16 ++++++++--------
 2 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/js/src/modal.js b/js/src/modal.js
index ca77359cabd4..d5f1c8c9ae99 100644
--- a/js/src/modal.js
+++ b/js/src/modal.js
@@ -60,7 +60,6 @@ const EVENT_MOUSEUP_DISMISS = `mouseup.dismiss${EVENT_KEY}`
 const EVENT_MOUSEDOWN_DISMISS = `mousedown.dismiss${EVENT_KEY}`
 const EVENT_CLICK_DATA_API = `click${EVENT_KEY}${DATA_API_KEY}`
 
-const CLASS_NAME_SCROLLABLE = 'modal-dialog-scrollable'
 const CLASS_NAME_SCROLLBAR_MEASURER = 'modal-scrollbar-measure'
 const CLASS_NAME_BACKDROP = 'modal-backdrop'
 const CLASS_NAME_OPEN = 'modal-open'
@@ -249,11 +248,10 @@ class Modal {
     this._element.style.display = 'block'
     this._element.removeAttribute('aria-hidden')
     this._element.setAttribute('aria-modal', true)
+    this._element.scrollTop = 0
 
-    if (this._dialog.classList.contains(CLASS_NAME_SCROLLABLE) && modalBody) {
+    if (modalBody) {
       modalBody.scrollTop = 0
-    } else {
-      this._element.scrollTop = 0
     }
 
     if (transition) {
diff --git a/js/tests/unit/modal.spec.js b/js/tests/unit/modal.spec.js
index c5fbc3a27392..52676844f4a8 100644
--- a/js/tests/unit/modal.spec.js
+++ b/js/tests/unit/modal.spec.js
@@ -382,40 +382,40 @@ describe('Modal', () => {
       modal.show()
     })
 
-    it('should set modal body scroll top to 0 if .modal-dialog-scrollable', done => {
+    it('should set .modal\'s scroll top to 0', done => {
       fixtureEl.innerHTML = [
         '<div class="modal fade">',
-        '  <div class="modal-dialog modal-dialog-scrollable">',
-        '    <div class="modal-body"></div>',
+        '  <div class="modal-dialog">',
         '  </div>',
         '</div>'
       ].join('')
 
       const modalEl = fixtureEl.querySelector('.modal')
-      const modalBody = modalEl.querySelector('.modal-body')
       const modal = new Modal(modalEl)
 
       modalEl.addEventListener('shown.bs.modal', () => {
-        expect(modalBody.scrollTop).toEqual(0)
+        expect(modalEl.scrollTop).toEqual(0)
         done()
       })
 
       modal.show()
     })
 
-    it('should set .modal\'s scroll top to 0 if .modal-dialog-scrollable and modal body do not exists', done => {
+    it('should set modal body scroll top to 0 if modal body do not exists', done => {
       fixtureEl.innerHTML = [
         '<div class="modal fade">',
-        '  <div class="modal-dialog modal-dialog-scrollable">',
+        '  <div class="modal-dialog">',
+        '    <div class="modal-body"></div>',
         '  </div>',
         '</div>'
       ].join('')
 
       const modalEl = fixtureEl.querySelector('.modal')
+      const modalBody = modalEl.querySelector('.modal-body')
       const modal = new Modal(modalEl)
 
       modalEl.addEventListener('shown.bs.modal', () => {
-        expect(modalEl.scrollTop).toEqual(0)
+        expect(modalBody.scrollTop).toEqual(0)
         done()
       })