Add initial prototype for the GN meta-buildsystem.

tools/gn/filesystem_utils_unittest.cc

Index: tools/gn/filesystem_utils_unittest.cc
diff --git a/tools/gn/filesystem_utils_unittest.cc b/tools/gn/filesystem_utils_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..75bf7cdb3a31c1bc8cc0582672433197e4e395ca
--- /dev/null
+++ b/tools/gn/filesystem_utils_unittest.cc
@@ -0,0 +1,146 @@
+// Copyright (c) 2013 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/strings/string_util.h"
+#include "base/strings/utf_string_conversions.h"
+#include "build/build_config.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "tools/gn/filesystem_utils.h"
+
+TEST(FilesystemUtils, FileExtensionOffset) {
+  EXPECT_EQ(std::string::npos, FindExtensionOffset(""));
+  EXPECT_EQ(std::string::npos, FindExtensionOffset("foo/bar/baz"));
+  EXPECT_EQ(4u, FindExtensionOffset("foo."));
+  EXPECT_EQ(4u, FindExtensionOffset("f.o.bar"));
+  EXPECT_EQ(std::string::npos, FindExtensionOffset("foo.bar/"));
+  EXPECT_EQ(std::string::npos, FindExtensionOffset("foo.bar/baz"));
+}
+
+TEST(FilesystemUtils, FindExtension) {
+  std::string input;
+  EXPECT_EQ("", FindExtension(&input).as_string());
+  input = "foo/bar/baz";
+  EXPECT_EQ("", FindExtension(&input).as_string());
+  input = "foo.";
+  EXPECT_EQ("", FindExtension(&input).as_string());
+  input = "f.o.bar";
+  EXPECT_EQ("bar", FindExtension(&input).as_string());
+  input = "foo.bar/";
+  EXPECT_EQ("", FindExtension(&input).as_string());
+  input = "foo.bar/baz";
+  EXPECT_EQ("", FindExtension(&input).as_string());
+}
+
+TEST(FilesystemUtils, FindFilenameOffset) {
+  EXPECT_EQ(0u, FindFilenameOffset(""));
+  EXPECT_EQ(0u, FindFilenameOffset("foo"));
+  EXPECT_EQ(4u, FindFilenameOffset("foo/"));
+  EXPECT_EQ(4u, FindFilenameOffset("foo/bar"));
+}
+
+TEST(FilesystemUtils, RemoveFilename) {
+  std::string s;
+
+  RemoveFilename(&s);
+  EXPECT_STREQ("", s.c_str());
+
+  s = "foo";
+  RemoveFilename(&s);
+  EXPECT_STREQ("", s.c_str());
+
+  s = "/";
+  RemoveFilename(&s);
+  EXPECT_STREQ("/", s.c_str());
+
+  s = "foo/bar";
+  RemoveFilename(&s);
+  EXPECT_STREQ("foo/", s.c_str());
+
+  s = "foo/bar/baz.cc";
+  RemoveFilename(&s);
+  EXPECT_STREQ("foo/bar/", s.c_str());
+}
+
+TEST(FilesystemUtils, FindDir) {
+  std::string input;
+  EXPECT_EQ("", FindDir(&input));
+  input = "/";
+  EXPECT_EQ("/", FindDir(&input));
+  input = "foo/";
+  EXPECT_EQ("foo/", FindDir(&input));
+  input = "foo/bar/baz";
+  EXPECT_EQ("foo/bar/", FindDir(&input));
+}
+
+TEST(FilesystemUtils, InvertDir) {
+  EXPECT_TRUE(InvertDir(SourceDir()) == "");
+  EXPECT_TRUE(InvertDir(SourceDir("/")) == "");
+  EXPECT_TRUE(InvertDir(SourceDir("//")) == "");
+
+  EXPECT_TRUE(InvertDir(SourceDir("//foo/bar")) == "../../");
+  EXPECT_TRUE(InvertDir(SourceDir("/foo/bar/")) == "../../");
+}
+
+TEST(FilesystemUtils, NormalizePath) {
+  std::string input;
+
+  NormalizePath(&input);
+  EXPECT_EQ("", input);
+
+  input = "foo/bar.txt";
+  NormalizePath(&input);
+  EXPECT_EQ("foo/bar.txt", input);
+
+  input = ".";
+  NormalizePath(&input);
+  EXPECT_EQ("", input);
+
+  input = "..";
+  NormalizePath(&input);
+  EXPECT_EQ("..", input);
+
+  input = "foo//bar";
+  NormalizePath(&input);
+  EXPECT_EQ("foo/bar", input);
+
+  input = "//foo";
+  NormalizePath(&input);
+  EXPECT_EQ("//foo", input);
+
+  input = "foo/..//bar";
+  NormalizePath(&input);
+  EXPECT_EQ("bar", input);
+
+  input = "foo/../../bar";
+  NormalizePath(&input);
+  EXPECT_EQ("../bar", input);
+
+  input = "/../foo";  // Don't go aboe the root dir.
+  NormalizePath(&input);
+  EXPECT_EQ("/foo", input);
+
+  input = "//../foo";  // Don't go aboe the root dir.
+  NormalizePath(&input);
+  EXPECT_EQ("//foo", input);
+
+  input = "../foo";
+  NormalizePath(&input);
+  EXPECT_EQ("../foo", input);
+
+  input = "..";
+  NormalizePath(&input);
+  EXPECT_EQ("..", input);
+
+  input = "./././.";
+  NormalizePath(&input);
+  EXPECT_EQ("", input);
+
+  input = "../../..";
+  NormalizePath(&input);
+  EXPECT_EQ("../../..", input);
+
+  input = "../";
+  NormalizePath(&input);
+  EXPECT_EQ("../", input);
+}