Improve readability of isValidElementType (#19251)

* improve readability

* replace condition by switch/case

* replace condition by switch/case

* remove unnecessary braces

* replace switch/case to ifs

* replace switch/case to ifs

* fix by multiline if statements

* fix multiple if statements

packages/shared/isValidElementType.js

@@ -28,28 +28,39 @@ import {
 } from 'shared/ReactSymbols';
 
 export default function isValidElementType(type: mixed) {
-  return (
-    typeof type === 'string' ||
-    typeof type === 'function' ||
-    // Note: its typeof might be other than 'symbol' or 'number' if it's a polyfill.
+  if (typeof type === 'string' || typeof type === 'function') {
+    return true;
+  }
+
+  // Note: typeof might be other than 'symbol' or 'number' (e.g. if it's a polyfill).
+  if (
     type === REACT_FRAGMENT_TYPE ||
     type === REACT_PROFILER_TYPE ||
     type === REACT_DEBUG_TRACING_MODE_TYPE ||
     type === REACT_STRICT_MODE_TYPE ||
     type === REACT_SUSPENSE_TYPE ||
     type === REACT_SUSPENSE_LIST_TYPE ||
-    type === REACT_LEGACY_HIDDEN_TYPE ||
-    (typeof type === 'object' &&
-      type !== null &&
-      (type.$$typeof === REACT_LAZY_TYPE ||
-        type.$$typeof === REACT_MEMO_TYPE ||
-        type.$$typeof === REACT_PROVIDER_TYPE ||
-        type.$$typeof === REACT_CONTEXT_TYPE ||
-        type.$$typeof === REACT_FORWARD_REF_TYPE ||
-        type.$$typeof === REACT_FUNDAMENTAL_TYPE ||
-        type.$$typeof === REACT_RESPONDER_TYPE ||
-        type.$$typeof === REACT_SCOPE_TYPE ||
-        type.$$typeof === REACT_BLOCK_TYPE ||
-        type[(0: any)] === REACT_SERVER_BLOCK_TYPE))
-  );
+    type === REACT_LEGACY_HIDDEN_TYPE
+  ) {
+    return true;
+  }
+
+  if (typeof type === 'object' && type !== null) {
+    if (
+      type.$$typeof === REACT_LAZY_TYPE ||
+      type.$$typeof === REACT_MEMO_TYPE ||
+      type.$$typeof === REACT_PROVIDER_TYPE ||
+      type.$$typeof === REACT_CONTEXT_TYPE ||
+      type.$$typeof === REACT_FORWARD_REF_TYPE ||
+      type.$$typeof === REACT_FUNDAMENTAL_TYPE ||
+      type.$$typeof === REACT_RESPONDER_TYPE ||
+      type.$$typeof === REACT_SCOPE_TYPE ||
+      type.$$typeof === REACT_BLOCK_TYPE ||
+      type[(0: any)] === REACT_SERVER_BLOCK_TYPE
+    ) {
+      return true;
+    }
+  }
+
+  return false;
 }