[clang-format] Handle constructor invocations after new operator in C# correct

Fixes #56549.

Differential Revision: https://reviews.llvm.org/D129926

Author: eoan-ermine

clang/lib/Format/UnwrappedLineParser.cpp

@@ -2975,6 +2975,11 @@ void UnwrappedLineParser::parseNew() {
 
   if (Style.isCSharp()) {
     do {
+      // Handle constructor invocation, e.g. `new(field: value)`.
+      if (FormatTok->is(tok::l_paren))
+        parseParens();
+
+      // Handle array initialization syntax, e.g. `new[] {10, 20, 30}`.
       if (FormatTok->is(tok::l_brace))
         parseBracedList();
 

clang/unittests/Format/FormatTestCSharp.cpp

@@ -617,6 +617,24 @@ var x = foo(className, $@"some code:
   EXPECT_EQ(Code, format(Code, Style));
 }
 
+TEST_F(FormatTestCSharp, CSharpNewOperator) {
+  FormatStyle Style = getLLVMStyle(FormatStyle::LK_CSharp);
+
+  verifyFormat("public void F() {\n"
+               "  var v = new C(() => { var t = 5; });\n"
+               "}",
+               Style);
+  verifyFormat("public void F() {\n"
+               "  var v = new C(() => {\n"
+               "    try {\n"
+               "    } catch {\n"
+               "      var t = 5;\n"
+               "    }\n"
+               "  });\n"
+               "}",
+               Style);
+}
+
 TEST_F(FormatTestCSharp, CSharpLambdas) {
   FormatStyle GoogleStyle = getGoogleStyle(FormatStyle::LK_CSharp);
   FormatStyle MicrosoftStyle = getMicrosoftStyle(FormatStyle::LK_CSharp);