gn: start of format command

tools/gn/command_format_unittest.cc

Index: tools/gn/command_format_unittest.cc
diff --git a/tools/gn/command_format_unittest.cc b/tools/gn/command_format_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f7fa0013808c53c02fac5cf45afb59d0964536fb
--- /dev/null
+++ b/tools/gn/command_format_unittest.cc
@@ -0,0 +1,45 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/files/file_util.h"
+#include "base/strings/string_util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "tools/gn/commands.h"
+
+namespace commands {
+bool FormatFileToString(const std::string& input_filename,
+                        bool dump_tree,
+                        std::string* output);
+}  // namespace commands
+
+#define FORMAT_TEST(n)                                                 \
+  TEST(Format, n) {                                                    \
+    std::string out;                                                   \
+    std::string expected;                                              \
+    EXPECT_TRUE(commands::FormatFileToString(                          \
+        "//tools/gn/format_test_data/" #n ".gn", false, &out));        \
+    ASSERT_TRUE(base::ReadFileToString(                                \
+        base::FilePath(FILE_PATH_LITERAL("tools/gn/format_test_data/") \
+                           FILE_PATH_LITERAL(#n)                       \
+                               FILE_PATH_LITERAL(".golden")),          \
+        &expected));                                                   \
+    EXPECT_EQ(out, expected);                                          \
+  }
+
+// These are expanded out this way rather than a runtime loop so that
+// --gtest_filter works as expected for individual test running.
+FORMAT_TEST(001)
+FORMAT_TEST(002)
+FORMAT_TEST(003)
+FORMAT_TEST(004)
+FORMAT_TEST(005)
+FORMAT_TEST(006)
+FORMAT_TEST(007)
+FORMAT_TEST(008)
+FORMAT_TEST(009)
+FORMAT_TEST(010)
+FORMAT_TEST(011)
+FORMAT_TEST(012)
+FORMAT_TEST(013)
+FORMAT_TEST(014)