Cleanup style checks (#44864)

Summary:
Pull Request resolved: #44864

Switch the style normalizer checks to only do a single top level `null` check and remove unneeded flow suppression comments.

Changelog: [Internal]

Reviewed By: javache

Differential Revision: D58386781

fbshipit-source-id: e4df6fdadb5bfab4c8ae674a420ac453ba262f78

packages/react-native/Libraries/Text/Text.js

@@ -212,33 +212,28 @@ const Text: React.AbstractComponent<
     default: accessible,
   });
 
-  // $FlowFixMe[underconstrained-implicit-instantiation]
-  style = flattenStyle(style);
+  let _selectable = restProps.selectable;
 
-  if (typeof style?.fontWeight === 'number') {
-    // $FlowFixMe[prop-missing]
-    // $FlowFixMe[cannot-write]
-    style.fontWeight = style?.fontWeight.toString();
-  }
+  const processedStyle = flattenStyle(style);
+  if (processedStyle != null) {
+    if (typeof processedStyle.fontWeight === 'number') {
+      // $FlowFixMe[cannot-write]
+      processedStyle.fontWeight = processedStyle.fontWeight.toString();
+    }
 
-  let _selectable = restProps.selectable;
-  if (style?.userSelect != null) {
-    // $FlowFixMe[invalid-computed-prop]
-    _selectable = userSelectToSelectableMap[style.userSelect];
-    // $FlowFixMe[prop-missing]
-    // $FlowFixMe[cannot-write]
-    delete style.userSelect;
-  }
+    if (processedStyle.userSelect != null) {
+      _selectable = userSelectToSelectableMap[processedStyle.userSelect];
+      // $FlowFixMe[cannot-write]
+      delete processedStyle.userSelect;
+    }
 
-  if (style?.verticalAlign != null) {
-    // $FlowFixMe[prop-missing]
-    // $FlowFixMe[cannot-write]
-    style.textAlignVertical =
-      // $FlowFixMe[invalid-computed-prop]
-      verticalAlignToTextAlignVerticalMap[style.verticalAlign];
-    // $FlowFixMe[prop-missing]
-    // $FlowFixMe[cannot-write]
-    delete style.verticalAlign;
+    if (processedStyle.verticalAlign != null) {
+      // $FlowFixMe[cannot-write]
+      processedStyle.textAlignVertical =
+        verticalAlignToTextAlignVerticalMap[processedStyle.verticalAlign];
+      // $FlowFixMe[cannot-write]
+      delete processedStyle.verticalAlign;
+    }
   }
 
   const _hasOnPressOrOnLongPress =
@@ -257,7 +252,7 @@ const Text: React.AbstractComponent<
       ref={forwardedRef}
       selectable={_selectable}
       selectionColor={selectionColor}
-      style={style}
+      style={processedStyle}
     />
   ) : (
     <TextAncestor.Provider value={true}>
@@ -280,7 +275,7 @@ const Text: React.AbstractComponent<
         ref={forwardedRef}
         selectable={_selectable}
         selectionColor={selectionColor}
-        style={style}
+        style={processedStyle}
       />
     </TextAncestor.Provider>
   );