fix resetting style on closing collapse

2 files changed, 16 insertions, 1 deletions

diff --git a/js/src/collapse.js b/js/src/collapse.js
index e46d3ec60..d95d6f28e 100644
--- a/js/src/collapse.js
+++ b/js/src/collapse.js
@@ -235,7 +235,7 @@ const Collapse = (($) => {
           .trigger(Event.HIDDEN)
       }
 
-      this._element.style[dimension] = 0
+      this._element.style[dimension] = ''
 
       if (!Util.supportsTransitionEnd()) {
         complete()
diff --git a/js/tests/unit/collapse.js b/js/tests/unit/collapse.js
index 78fafc6c2..e1bd8855c 100644
--- a/js/tests/unit/collapse.js
+++ b/js/tests/unit/collapse.js
@@ -78,6 +78,21 @@ $(function () {
       .bootstrapCollapse('show')
   })
 
+  QUnit.test('should reset style to auto after finishing closing collapse', function (assert) {
+    assert.expect(1)
+    var done = assert.async()
+
+    $('<div class="collapse"/>')
+      .on('shown.bs.collapse', function () {
+        $(this).bootstrapCollapse('hide')
+      })
+      .on('hidden.bs.collapse', function () {
+        assert.strictEqual(this.style.height, '', 'height is auto')
+        done()
+      })
+      .bootstrapCollapse('show')
+  })
+
   QUnit.test('should remove "collapsed" class from target when collapse is shown', function (assert) {
     assert.expect(1)
     var done = assert.async()