clang-format: [JS] Fix bug in type colon detection.

Before, this couldn't be formatted at all:
  class X {
    subs = {
      'b': {
        'c': 1,
      },
    };
  }

llvm-svn: 238907
diff --git a/clang/lib/Format/TokenAnnotator.cpp b/clang/lib/Format/TokenAnnotator.cpp
index 3c1c9a1..6b59cb3 100644
--- a/clang/lib/Format/TokenAnnotator.cpp
+++ b/clang/lib/Format/TokenAnnotator.cpp
@@ -448,7 +448,8 @@
              !Line.First->isOneOf(tok::kw_enum, tok::kw_case)) ||
             Contexts.back().ContextKind == tok::l_paren ||  // function params
             Contexts.back().ContextKind == tok::l_square || // array type
-            Line.MustBeDeclaration) { // method/property declaration
+            (Contexts.size() == 1 &&
+             Line.MustBeDeclaration)) { // method/property declaration
           Tok->Type = TT_JsTypeColon;
           break;
         }
diff --git a/clang/unittests/Format/FormatTestJS.cpp b/clang/unittests/Format/FormatTestJS.cpp
index 80a3e0a..3ed3cde 100644
--- a/clang/unittests/Format/FormatTestJS.cpp
+++ b/clang/unittests/Format/FormatTestJS.cpp
@@ -631,6 +631,15 @@
   verifyFormat("class C {\n  static x(): string { return 'asd'; }\n}");
   verifyFormat("class C extends P implements I {}");
   verifyFormat("class C extends p.P implements i.I {}");
+
+  // ':' is not a type declaration here.
+  verifyFormat("class X {\n"
+               "  subs = {\n"
+               "    'b': {\n"
+               "      'c': 1,\n"
+               "    },\n"
+               "  };\n"
+               "}");
 }
 
 TEST_F(FormatTestJS, InterfaceDeclarations) {