Make HAS_BEFORE_INPUT_SUPPORT flag more generic. (#4118)

* Change "HAS_BEFORE_INPUT_SUPPORT" flag to more generic.

* Fix patterns and styles issues.

* Fix lint issues.

* Create dirty-rabbits-speak.md

* Update dirty-rabbits-speak.md

* Update editable.tsx

Co-authored-by: Ian Storm Taylor <ian@ianstormtaylor.com>

.changeset/dirty-rabbits-speak.md

@@ -0,0 +1,5 @@
+---
+'slate-react': patch
+---
+
+Improved detection of legacy browsers that don't have proper `beforeinput` support.

packages/slate-react/src/components/editable.tsx

@@ -21,7 +21,6 @@ import {
   IS_SAFARI,
   IS_EDGE_LEGACY,
   IS_CHROME_LEGACY,
-  IS_FIREFOX_LEGACY,
 } from '../utils/environment'
 import { ReactEditor } from '..'
 import { ReadOnlyContext } from '../hooks/use-read-only'
@@ -50,11 +49,12 @@ import {
 
 // COMPAT: Firefox/Edge Legacy don't support the `beforeinput` event
 // Chrome Legacy doesn't support `beforeinput` correctly
-const HAS_BEFORE_INPUT_SUPPORT = !(
-  IS_FIREFOX_LEGACY ||
-  IS_EDGE_LEGACY ||
-  IS_CHROME_LEGACY
-)
+const HAS_BEFORE_INPUT_SUPPORT =
+  !IS_CHROME_LEGACY &&
+  !IS_EDGE_LEGACY &&
+  globalThis.InputEvent &&
+  // @ts-ignore The `getTargetRanges` property isn't recognized.
+  typeof globalThis.InputEvent.prototype.getTargetRanges === 'function'
 
 /**
  * `RenderElementProps` are passed to the `renderElement` handler.