Support printing scopes in GN

tools/gn/value_unittest.cc

Index: tools/gn/value_unittest.cc
diff --git a/tools/gn/value_unittest.cc b/tools/gn/value_unittest.cc
index c7d49488d884798e476888b5a891897977d61d18..3fa990d4a28e915190c927f4fd36153f0a8c9b02 100644
--- a/tools/gn/value_unittest.cc
+++ b/tools/gn/value_unittest.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "testing/gtest/include/gtest/gtest.h"
+#include "tools/gn/test_with_scope.h"
 #include "tools/gn/value.h"
 
 TEST(Value, ToString) {
@@ -10,6 +11,9 @@ TEST(Value, ToString) {
   EXPECT_EQ("hi\" $me\\you\\$\\\"", strval.ToString(false));
   EXPECT_EQ("\"hi\\\" \\$me\\you\\\\\\$\\\\\\\"\"", strval.ToString(true));
 
+  // Void type.
+  EXPECT_EQ("<void>", Value().ToString(false));
+
   // Test lists, bools, and ints.
   Value listval(NULL, Value::LIST);
   listval.list_value().push_back(Value(NULL, "hi\"me"));
@@ -21,9 +25,14 @@ TEST(Value, ToString) {
   EXPECT_EQ("[\"hi\\\"me\", true, false, 42]", listval.ToString(false));
   EXPECT_EQ("[\"hi\\\"me\", true, false, 42]", listval.ToString(true));
 
-  // Some weird types, we may want to enhance or change printing of these, but
-  // here we test the current behavior.
-  EXPECT_EQ("<void>", Value().ToString(false));
-  EXPECT_EQ("<scope>", Value(NULL, Value::SCOPE).ToString(false));
+  // Scopes.
+  TestWithScope setup;
+  Scope* scope = new Scope(setup.scope());
+  Value scopeval(NULL, scoped_ptr<Scope>(scope));
+  EXPECT_EQ("{ }", scopeval.ToString(false));
+
+  scope->SetValue("a", Value(NULL, static_cast<int64>(42)), NULL);
+  scope->SetValue("b", Value(NULL, "hello, world"), NULL);
+  EXPECT_EQ("{\n  a = 42\n  b = \"hello, world\"\n}", scopeval.ToString(false));
 }