clang-format: [JS] post-fix non-null assertion operator.

Summary:
Do not insert whitespace preceding the "!" postfix operator. This is an
incomplete fix, but should cover common usage.

Reviewers: djasper

Subscribers: cfe-commits, klimek

Differential Revision: http://reviews.llvm.org/D21204

llvm-svn: 272524
diff --git a/clang/unittests/Format/FormatTestJS.cpp b/clang/unittests/Format/FormatTestJS.cpp
index 3d96779..ffcc34d 100644
--- a/clang/unittests/Format/FormatTestJS.cpp
+++ b/clang/unittests/Format/FormatTestJS.cpp
@@ -1293,5 +1293,14 @@
                "var x   =  hello();");
 }
 
+TEST_F(FormatTestJS, NonNullAssertionOperator) {
+  verifyFormat("let x = foo!.bar();\n");
+  verifyFormat("let x = foo ? bar! : baz;\n");
+  verifyFormat("let x = !foo;\n");
+  verifyFormat("let x = foo[0]!;\n");
+  verifyFormat("let x = (foo)!;\n");
+  verifyFormat("let x = {foo: 1}!;\n");
+}
+
 } // end namespace tooling
 } // end namespace clang