Index: clang/lib/Format/TokenAnnotator.cpp
===================================================================
--- clang/lib/Format/TokenAnnotator.cpp
+++ clang/lib/Format/TokenAnnotator.cpp
@@ -2836,6 +2836,36 @@
 bool TokenAnnotator::spaceRequiredBefore(const AnnotatedLine &Line,
                                          const FormatToken &Right) {
   const FormatToken &Left = *Right.Previous;
+  if (Style.isCSharp()) {
+    // Require spaces around '{' and  before '}' unless they appear in
+    // interpolated strings. Interpolated strings are merged into a single token
+    // so cannot have spaces inserted by this function.
+
+    // Space before {
+    if (Left.isOneOf(tok::identifier, tok::r_paren, tok::r_square,
+                     tok::greater) &&
+        Right.is(tok::l_brace))
+      return true;
+
+    // Spaces inside braces.
+    if (Left.is(tok::l_brace) &&
+        Right.isOneOf(tok::kw_new, tok::identifier, tok::string_literal,
+                      tok::r_paren, tok::l_square, tok::numeric_constant,
+                      tok::kw_true, tok::kw_false, tok::kw_typeof))
+      return true;
+    if (Left.isOneOf(tok::identifier, tok::string_literal, tok::r_paren,
+                     tok::r_square, tok::numeric_constant, tok::kw_true,
+                     tok::kw_false) &&
+        Right.is(tok::r_brace))
+      return true;
+
+    // Spaces around '=>'.
+    if (Left.is(TT_JsFatArrow) || Right.is(TT_JsFatArrow))
+      return true;
+    // No space between identifier and '['.
+    if (Left.is(tok::identifier) && Right.is(tok::l_square))
+      return false;
+  }
   if (Right.Tok.getIdentifierInfo() && Left.Tok.getIdentifierInfo())
     return true; // Never ever merge two identifiers.
   if (Style.isCpp()) {
Index: clang/unittests/Format/FormatTestCSharp.cpp
===================================================================
--- clang/unittests/Format/FormatTestCSharp.cpp
+++ clang/unittests/Format/FormatTestCSharp.cpp
@@ -525,11 +525,11 @@
 
   // Omitted final `,`s will change the formatting.
   verifyFormat(R"(//
-Shape[] shapes = new[] {new Circle {Radius = 2.7281, Colour = Colours.Red},
-                        new Square {
-                            Side = 101.1,
-                            Colour = Colours.Yellow,
-                        }};)",
+Shape[] shapes = new[] { new Circle { Radius = 2.7281, Colour = Colours.Red },
+                         new Square {
+                             Side = 101.1,
+                             Colour = Colours.Yellow,
+                         }};)",
                Style);
 }
 
@@ -575,5 +575,20 @@
                Style);
 }
 
+TEST_F(FormatTestCSharp, CSharpSpaces) {
+  FormatStyle Style = getGoogleStyle(FormatStyle::LK_CSharp);
+
+  verifyFormat(R"(new Car { "Door", 0.1 })", Style);
+  verifyFormat(R"(new Car { 0.1, "Door" })", Style);
+  verifyFormat(R"(new string[] { "A" })", Style);
+  verifyFormat(R"(new string[] {})", Style);
+  verifyFormat(R"(new Car { someVariableName })", Style);
+  verifyFormat(R"(new Car { someVariableName })", Style);
+  verifyFormat(R"(new Dictionary<string, string> { ["Key"] = "Value" };)",
+               Style);
+  verifyFormat(R"(Apply(x => x.Name, x => () => x.ID);)", Style);
+  verifyFormat(R"(bool[] xs = { true, true };)", Style);
+}
+
 } // namespace format
 } // end namespace clang