Drop Legacy Edge support.

This allows us to move forward without being held back. Microsoft already replaces the Legacy Edge with the new one on supported Windows versions.

13 files changed, 11 insertions, 127 deletions

diff --git a/.browserslistrc b/.browserslistrc
index c17ce9049c..122986c8eb 100644
--- a/.browserslistrc
+++ b/.browserslistrc
@@ -5,7 +5,9 @@ last 1 major version
 not dead
 Chrome >= 60
 Firefox >= 60
-Edge >= 16
+# needed since Legacy Edge still has usage; 79 was the first Chromium Edge version
+# should be removed in the future when its usage drops or when it's moved to dead browsers
+not Edge < 79
 iOS >= 10
 Safari >= 10
 Android >= 6
diff --git a/js/src/dom/event-handler.js b/js/src/dom/event-handler.js
index 1d109c57ec..c228e21ba1 100644
--- a/js/src/dom/event-handler.js
+++ b/js/src/dom/event-handler.js
@@ -6,7 +6,6 @@
  */
 
 import { getjQuery } from '../util/index'
-import { defaultPreventedPreservedOnDispatch } from './polyfill'
 
 /**
  * ------------------------------------------------------------------------
@@ -314,12 +313,6 @@ const EventHandler = {
 
     if (defaultPrevented) {
       evt.preventDefault()
-
-      if (!defaultPreventedPreservedOnDispatch) {
-        Object.defineProperty(evt, 'defaultPrevented', {
-          get: () => true
-        })
-      }
     }
 
     if (nativeDispatch) {
diff --git a/js/src/dom/polyfill.js b/js/src/dom/polyfill.js
index ed982587b6..c5318a1300 100644
--- a/js/src/dom/polyfill.js
+++ b/js/src/dom/polyfill.js
@@ -10,20 +10,6 @@ import { getUID } from '../util/index'
 let find = Element.prototype.querySelectorAll
 let findOne = Element.prototype.querySelector
 
-// MSEdge resets defaultPrevented flag upon dispatchEvent call if at least one listener is attached
-const defaultPreventedPreservedOnDispatch = (() => {
-  const e = new CustomEvent('Bootstrap', {
-    cancelable: true
-  })
-
-  const element = document.createElement('div')
-  element.addEventListener('Bootstrap', () => null)
-
-  e.preventDefault()
-  element.dispatchEvent(e)
-  return e.defaultPrevented
-})()
-
 const scopeSelectorRegex = /:scope\b/
 const supportsScopeQuery = (() => {
   const element = document.createElement('div')
@@ -75,6 +61,5 @@ if (!supportsScopeQuery) {
 
 export {
   find,
-  findOne,
-  defaultPreventedPreservedOnDispatch
+  findOne
 }
diff --git a/js/tests/browsers.js b/js/tests/browsers.js
index 68c26a19e9..828edfe079 100644
--- a/js/tests/browsers.js
+++ b/js/tests/browsers.js
@@ -23,13 +23,6 @@ const browsers = {
     browser: 'Firefox',
     browser_version: 'latest'
   },
-  edgeWin10: {
-    base: 'BrowserStack',
-    os: 'Windows',
-    os_version: '10',
-    browser: 'Edge',
-    browser_version: '16'
-  },
   chromeWin10: {
     base: 'BrowserStack',
     os: 'Windows',
diff --git a/scss/_reboot.scss b/scss/_reboot.scss
index 35d5bbd992..2d70e533a4 100644
--- a/scss/_reboot.scss
+++ b/scss/_reboot.scss
@@ -295,8 +295,6 @@ samp {
 // 1. Remove browser default top margin
 // 2. Reset browser default of `1em` to use `rem`s
 // 3. Don't allow content to break outside
-// 4. Disable auto-hiding scrollbar in legacy Edge to avoid overlap,
-//    making it impossible to interact with the content
 
 pre {
   display: block;
@@ -305,7 +303,6 @@ pre {
   overflow: auto; // 3
   @include font-size($code-font-size);
   color: $pre-color;
-  -ms-overflow-style: scrollbar; // 4
 
   // Account for some code outputs that place code tags in pre tags
   code {
@@ -434,13 +431,6 @@ textarea {
   line-height: inherit;
 }
 
-// Show the overflow in Edge
-
-button,
-input {
-  overflow: visible;
-}
-
 // Remove the inheritance of text transform in Firefox
 
 button,
@@ -516,8 +506,7 @@ fieldset {
 
 // 1. By using `float: left`, the legend will behave like a block element.
 //    This way the border of a fieldset wraps around the legend if present.
-// 2. Correct the text wrapping in Edge.
-// 3. Fix wrapping bug.
+// 2. Fix wrapping bug.
 //    See https://github.com/twbs/bootstrap/issues/29712
 
 legend {
@@ -528,10 +517,9 @@ legend {
   @include font-size($legend-font-size);
   font-weight: $legend-font-weight;
   line-height: inherit;
-  white-space: normal; // 2
 
   + * {
-    clear: left; // 3
+    clear: left; // 2
   }
 }
 
diff --git a/scss/forms/_floating-labels.scss b/scss/forms/_floating-labels.scss
index b35f1c3bdc..42e56f27b3 100644
--- a/scss/forms/_floating-labels.scss
+++ b/scss/forms/_floating-labels.scss
@@ -61,25 +61,3 @@
   }
   // stylelint-enable no-duplicate-selectors
 }
-
-
-//
-// Fallback for classic Edge
-//
-
-@supports (-ms-ime-align: auto) {
-  .form-floating {
-    display: flex;
-    flex-direction: column-reverse;
-  }
-  .form-floating > label {
-    position: static;
-    padding: 0;
-    margin-bottom: calc(#{$form-floating-padding-y} / 2); // stylelint-disable-line function-disallowed-list
-    border: 0;
-    @include transition(none);
-  }
-  .form-floating > .form-control::-ms-input-placeholder {
-    color: $input-placeholder-color;
-  }
-}
diff --git a/scss/forms/_form-range.scss b/scss/forms/_form-range.scss
index 6cf90138d3..b603a7bc35 100644
--- a/scss/forms/_form-range.scss
+++ b/scss/forms/_form-range.scss
@@ -18,7 +18,6 @@
     // No box-shadow() mixin for focus accessibility.
     &::-webkit-slider-thumb { box-shadow: $form-range-thumb-focus-box-shadow; }
     &::-moz-range-thumb     { box-shadow: $form-range-thumb-focus-box-shadow; }
-    &::-ms-thumb            { box-shadow: $form-range-thumb-focus-box-shadow; }
   }
 
   &::-moz-focus-outer {
@@ -78,46 +77,6 @@
     @include box-shadow($form-range-track-box-shadow);
   }
 
-  &::-ms-thumb {
-    width: $form-range-thumb-width;
-    height: $form-range-thumb-height;
-    margin-top: 0; // Edge specific
-    margin-right: $form-range-thumb-focus-box-shadow-width; // Workaround that overflowed box-shadow is hidden.
-    margin-left: $form-range-thumb-focus-box-shadow-width;  // Workaround that overflowed box-shadow is hidden.
-    @include gradient-bg($form-range-thumb-bg);
-    border: $form-range-thumb-border;
-    @include border-radius($form-range-thumb-border-radius);
-    @include box-shadow($form-range-thumb-box-shadow);
-    @include transition($form-range-thumb-transition);
-    appearance: none;
-
-    &:active {
-      @include gradient-bg($form-range-thumb-active-bg);
-    }
-  }
-
-  &::-ms-track {
-    width: $form-range-track-width;
-    height: $form-range-track-height;
-    color: transparent;
-    cursor: $form-range-track-cursor;
-    background-color: transparent;
-    border-color: transparent;
-    border-width: $form-range-thumb-height / 2;
-    @include box-shadow($form-range-track-box-shadow);
-  }
-
-  &::-ms-fill-lower {
-    background-color: $form-range-track-bg;
-    @include border-radius($form-range-track-border-radius);
-  }
-
-  &::-ms-fill-upper {
-    margin-right: 15px; // arbitrary?
-    background-color: $form-range-track-bg;
-    @include border-radius($form-range-track-border-radius);
-  }
-
   &:disabled {
     pointer-events: none;
 
@@ -128,9 +87,5 @@
     &::-moz-range-thumb {
       background-color: $form-range-thumb-disabled-bg;
     }
-
-    &::-ms-thumb {
-      background-color: $form-range-thumb-disabled-bg;
-    }
   }
 }
diff --git a/scss/forms/_form-select.scss b/scss/forms/_form-select.scss
index 6ebe33e102..1866da9647 100644
--- a/scss/forms/_form-select.scss
+++ b/scss/forms/_form-select.scss
@@ -32,16 +32,6 @@
       // Avoid using mixin so we can pass custom focus shadow properly
       box-shadow: $form-select-focus-box-shadow;
     }
-
-    &::-ms-value {
-      // For visual consistency with other platforms/browsers,
-      // suppress the default white text on blue background highlight given to
-      // the selected option text when the (still closed) <select> receives focus
-      // in Edge.
-      // See https://github.com/twbs/bootstrap/issues/19398.
-      color: $input-color;
-      background-color: $input-bg;
-    }
   }
 
   &[multiple],
diff --git a/site/assets/scss/_component-examples.scss b/site/assets/scss/_component-examples.scss
index 9e3e1c6539..b29635500b 100644
--- a/site/assets/scss/_component-examples.scss
+++ b/site/assets/scss/_component-examples.scss
@@ -273,7 +273,6 @@
   padding: 1rem;
   margin-bottom: 1rem;
   background-color: $gray-100;
-  -ms-overflow-style: -ms-autohiding-scrollbar;
 
   @include media-breakpoint-up(sm) {
     padding: 1rem 1.5rem;
diff --git a/site/content/docs/5.0/forms/floating-labels.md b/site/content/docs/5.0/forms/floating-labels.md
index 16f7f08e07..d324aa92d0 100644
--- a/site/content/docs/5.0/forms/floating-labels.md
+++ b/site/content/docs/5.0/forms/floating-labels.md
@@ -10,8 +10,6 @@ toc: true
 
 Wrap a pair of `<input class="form-control">` and `<label>` elements in `.form-floating` to enable floating labels with Bootstrap's textual form fields. A `placeholder` is required on each `<input>` as our method of CSS-only floating labels uses the `:placeholder-shown` pseudo-element. Also note that the `<input>` must come first so we can utilize a sibling selector (e.g., `~`).
 
-This approach works in the new Microsoft Edge built on Chromium and gracefully degrades on older versions.
-
 {{< example >}}
 <div class="form-floating mb-3">
   <input type="email" class="form-control" id="floatingInput" placeholder="name@example.com">
diff --git a/site/content/docs/5.0/getting-started/browsers-devices.md b/site/content/docs/5.0/getting-started/browsers-devices.md
index 572cf5e47c..7dc0743b74 100644
--- a/site/content/docs/5.0/getting-started/browsers-devices.md
+++ b/site/content/docs/5.0/getting-started/browsers-devices.md
@@ -8,7 +8,7 @@ toc: true
 
 ## Supported browsers
 
-Bootstrap supports the **latest, stable releases** of all major browsers and platforms. This also includes the latest version of Legacy Edge (EdgeHTML layout engine).
+Bootstrap supports the **latest, stable releases** of all major browsers and platforms.
 
 Alternative browsers which use the latest version of WebKit, Blink, or Gecko, whether directly or via the platform's web view API, are not explicitly supported. However, Bootstrap should (in most cases) display and function correctly in these browsers as well. More specific support information is provided below.
 
diff --git a/site/content/docs/5.0/migration.md b/site/content/docs/5.0/migration.md
index d4370fe530..64ee838244 100644
--- a/site/content/docs/5.0/migration.md
+++ b/site/content/docs/5.0/migration.md
@@ -9,6 +9,10 @@ toc: true
 
 ## v5.0.0-alpha3
 
+### Browser support
+
+- Dropped support for Microsoft Edge Legacy. See [here](#browser-support-1) for the previous browser support changes.
+
 ### Colors
 
 - The color system which worked with `color-level()` and `$theme-color-interval` was removed in favor of a new color system.
diff --git a/site/layouts/_default/examples.html b/site/layouts/_default/examples.html
index 3fe1ac9bdd..9782e6a448 100644
--- a/site/layouts/_default/examples.html
+++ b/site/layouts/_default/examples.html
@@ -23,7 +23,6 @@
         text-anchor: middle;
         -webkit-user-select: none;
         -moz-user-select: none;
-        -ms-user-select: none;
         user-select: none;
       }