Fix a bug in inline method refactoring

pkg/analysis_server/lib/src/services/correction/util.dart

Index: pkg/analysis_server/lib/src/services/correction/util.dart
diff --git a/pkg/analysis_server/lib/src/services/correction/util.dart b/pkg/analysis_server/lib/src/services/correction/util.dart
index 3ff5405bb4147157fda838eec4b7b09393672f04..2e73715e74333551b069e6ef61ec3a653912cef7 100644
--- a/pkg/analysis_server/lib/src/services/correction/util.dart
+++ b/pkg/analysis_server/lib/src/services/correction/util.dart
@@ -317,9 +317,17 @@ int getExpressionParentPrecedence(AstNode node) {
   AstNode parent = node.parent;
   if (parent is ParenthesizedExpression) {
     return 0;
-  }
-  if (parent is IndexExpression && parent.index == node) {
+  } else if (parent is IndexExpression && parent.index == node) {
     return 0;
+  } else if (parent is AssignmentExpression &&
+      node == parent.rightHandSide &&
+      parent.parent is CascadeExpression) {
+    // This is a hack to allow nesting of cascade expressions within other
+    // cascade expressions. The problem is that if the precedence of two
+    // expressions are equal it sometimes means that we don't need parentheses
+    // (such as replacing the `b` in `a + b` with `c + d`) and sometimes do
+    // (such as replacing the `v` in `..f = v` with `a..b`).
+    return 3;
   }
   return getExpressionPrecedence(parent);
 }