From 5236dd0793d8ddfcd2ab1cbc87b7328f96552926 Mon Sep 17 00:00:00 2001
From: Oleksandr T <oleksandr.tarasiuk@outlook.com>
Date: Fri, 21 Oct 2022 09:54:22 +0300
Subject: [PATCH 1/2] fix(51245): don't rely on parent nodes in formatting
 rules

---
 src/services/formatting/rules.ts              | 12 +---------
 ... refactorConvertExport_namedToDefault1.ts} |  0
 .../refactorConvertExport_namedToDefault2.ts  | 23 +++++++++++++++++++
 3 files changed, 24 insertions(+), 11 deletions(-)
 rename tests/cases/fourslash/{refactorConvertExport_namedToDefault.ts => refactorConvertExport_namedToDefault1.ts} (100%)
 create mode 100644 tests/cases/fourslash/refactorConvertExport_namedToDefault2.ts

diff --git a/src/services/formatting/rules.ts b/src/services/formatting/rules.ts
index 85e67eb8cbb59..59090f56e264e 100644
--- a/src/services/formatting/rules.ts
+++ b/src/services/formatting/rules.ts
@@ -725,17 +725,7 @@ namespace ts.formatting {
     }
 
     function isEndOfDecoratorContextOnSameLine(context: FormattingContext): boolean {
-        return context.TokensAreOnSameLine() &&
-            hasDecorators(context.contextNode) &&
-            nodeIsInDecoratorContext(context.currentTokenParent) &&
-            !nodeIsInDecoratorContext(context.nextTokenParent);
-    }
-
-    function nodeIsInDecoratorContext(node: Node): boolean {
-        while (isExpressionNode(node)) {
-            node = node.parent;
-        }
-        return node.kind === SyntaxKind.Decorator;
+        return context.TokensAreOnSameLine() && hasDecorators(context.contextNode) && isDecorator(context.currentTokenParent);
     }
 
     function isStartOfVariableDeclarationList(context: FormattingContext): boolean {
diff --git a/tests/cases/fourslash/refactorConvertExport_namedToDefault.ts b/tests/cases/fourslash/refactorConvertExport_namedToDefault1.ts
similarity index 100%
rename from tests/cases/fourslash/refactorConvertExport_namedToDefault.ts
rename to tests/cases/fourslash/refactorConvertExport_namedToDefault1.ts
diff --git a/tests/cases/fourslash/refactorConvertExport_namedToDefault2.ts b/tests/cases/fourslash/refactorConvertExport_namedToDefault2.ts
new file mode 100644
index 0000000000000..3692e8493a5ae
--- /dev/null
+++ b/tests/cases/fourslash/refactorConvertExport_namedToDefault2.ts
@@ -0,0 +1,23 @@
+/// <reference path='fourslash.ts' />
+
+// @Filename: /a.ts
+/////*a*/export const f = () => {
+////    return class C {
+////        constructor(@Foo() param: any) { }
+////    }
+////}/*b*/
+////function Foo(...args: any[]): any {}
+
+goTo.select("a", "b");
+edit.applyRefactor({
+    refactorName: "Convert export",
+    actionName: "Convert named export to default export",
+    actionDescription: "Convert named export to default export",
+    newContent:
+`export default () => {
+    return class C {
+        constructor(@Foo() param: any) { }
+    }
+}
+function Foo(...args: any[]): any {}`,
+});

From 2b1d5db5efd67f5f402ec7f05810ab68774afa4f Mon Sep 17 00:00:00 2001
From: Oleksandr T <oleksandr.tarasiuk@outlook.com>
Date: Tue, 25 Oct 2022 20:15:09 +0300
Subject: [PATCH 2/2] check existing parent node

---
 src/services/formatting/rules.ts | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/services/formatting/rules.ts b/src/services/formatting/rules.ts
index 59090f56e264e..07724be25ba0e 100644
--- a/src/services/formatting/rules.ts
+++ b/src/services/formatting/rules.ts
@@ -725,7 +725,17 @@ namespace ts.formatting {
     }
 
     function isEndOfDecoratorContextOnSameLine(context: FormattingContext): boolean {
-        return context.TokensAreOnSameLine() && hasDecorators(context.contextNode) && isDecorator(context.currentTokenParent);
+        return context.TokensAreOnSameLine() &&
+            hasDecorators(context.contextNode) &&
+            nodeIsInDecoratorContext(context.currentTokenParent) &&
+            !nodeIsInDecoratorContext(context.nextTokenParent);
+    }
+
+    function nodeIsInDecoratorContext(node: Node): boolean {
+        while (node && isExpression(node)) {
+            node = node.parent;
+        }
+        return node && node.kind === SyntaxKind.Decorator;
     }
 
     function isStartOfVariableDeclarationList(context: FormattingContext): boolean {