Handle null in hasDirectAnnotationWithSimpleName

And use pattern switches and other small cleanups.

#4307

PiperOrigin-RevId: 902595762

Author: cushon

check_api/src/main/java/com/google/errorprone/util/ASTHelpers.java

@@ -1007,30 +1007,34 @@ private static Set<Name> directAnnotationsAmong(
    * annotation inheritance (see JLS 9.6.4.3).
    */
   public static boolean hasDirectAnnotationWithSimpleName(Symbol sym, String simpleName) {
-    if (sym instanceof MethodSymbol methodSymbol) {
-      return hasDirectAnnotationWithSimpleName(methodSymbol, simpleName);
-    }
-    if (sym instanceof VarSymbol varSymbol) {
-      return hasDirectAnnotationWithSimpleName(varSymbol, simpleName);
-    }
-    return hasDirectAnnotation(
-        sym.getAnnotationMirrors().stream(),
-        element -> element.getSimpleName().contentEquals(simpleName));
+    return switch (sym) {
+      case MethodSymbol methodSymbol -> hasDirectAnnotationWithSimpleName(methodSymbol, simpleName);
+      case VarSymbol varSymbol -> hasDirectAnnotationWithSimpleName(varSymbol, simpleName);
+      case null -> false;
+      default -> hasDirectAnnotationWithSimpleName(sym.getAnnotationMirrors().stream(), simpleName);
+    };
   }
 
   public static boolean hasDirectAnnotationWithSimpleName(MethodSymbol sym, String simpleName) {
-    return hasDirectAnnotation(
+    return hasDirectAnnotationWithSimpleName(
         Streams.concat(
             sym.getAnnotationMirrors().stream(),
             sym.getReturnType().getAnnotationMirrors().stream()),
-        element -> element.getSimpleName().contentEquals(simpleName));
+        simpleName);
   }
 
   public static boolean hasDirectAnnotationWithSimpleName(VarSymbol sym, String simpleName) {
-    return hasDirectAnnotation(
+    return hasDirectAnnotationWithSimpleName(
         Streams.concat(
             sym.getAnnotationMirrors().stream(), sym.asType().getAnnotationMirrors().stream()),
-        element -> element.getSimpleName().contentEquals(simpleName));
+        simpleName);
+  }
+
+  private static boolean hasDirectAnnotationWithSimpleName(
+      Stream<? extends AnnotationMirror> annotations, String simpleName) {
+    return annotations.anyMatch(
+        annotation ->
+            annotation.getAnnotationType().asElement().getSimpleName().contentEquals(simpleName));
   }
 
   /**