Add path utils, plus a test for it.

tests/OSPathUtilsTest.cpp

+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkString.h"
+#include "SkOSFile.h"
+#include "SkOSPathUtils.h"
+#include "Test.h"
+
+static void test_dir_with_file(skiatest::Reporter* reporter, SkString dir,

[epoger, 2013/05/22 17:33:58]

Please add documentation stating what this method does, including a note that
SkPATH_SEPARATOR should not be present in filename.

[scroggo, 2013/05/23 15:29:33]

Done.

+                               SkString filename) {
+#ifdef SK_DEBUG

[epoger, 2013/05/22 17:33:58]

Why the #ifdef here?  Seems like this code can always be included...

[scroggo, 2013/05/23 15:29:33]

Because it's only here for the SkASSERT. In release mode, we won't run the
assert statement, so there is no need for the prior code.

That said, the setup code has been removed, so the entire SkASSERT is
self-contained.

+    // If filename contains SkPATH_SEPARATOR, the tests will fail.
+    SkString pathSeparator;
+    pathSeparator.appendUnichar(SkPATH_SEPARATOR);
+    SkASSERT(!filename.contains(pathSeparator.c_str()));

[epoger, 2013/05/22 17:33:58]

Why not just 

SkASSERT(!filename.contains(SkPATH_SEPARATOR))

[scroggo, 2013/05/23 15:29:33]

Done.

+#endif
+    // Tests for SkPathJoin and SkBasename
+    // fullName should be "dir<SkPATH_SEPARATOR>file"

[epoger, 2013/05/22 17:33:58]

I think this code would be easier to read with some extra newlines, like this:

// Tests for SkPathJoin and SkBasename

// fullName should be "dir<SkPATH_SEPARATOR>file"
SkString fullName = SkPathJoin(dir.c_str(), filename.c_str());

// basename should be the same as filename
REPORTER_ASSERT(reporter, 0 == strcmp(basename, filename.c_str()));

// Now take the basename of filename, which should be the same as filename
basename = SkBasename(filename.c_str());
REPORTER_ASSERT(reporter, 0 == strcmp(basename, filename.c_str()));

[scroggo, 2013/05/23 15:29:33]

Done.

+    SkString fullName = SkPathJoin(dir.c_str(), filename.c_str());
+    // fullName should be the combined size of dir and file, plus one if
+    // dir did not include the final path separator.
+    REPORTER_ASSERT(reporter, fullName.size() == dir.size() + filename.size()

[epoger, 2013/05/22 17:33:58]

Maybe this tighter test instead?

if (dir.endsWith(SkPATH_SEPARATOR)) {
  expectedSize = dir.size() + filename.size();
} else {
  expectedSize = dir.size() + filename.size() + 1;
}
REPORTER_ASSERT(reporter, expectedSize == fullName.size());

[scroggo, 2013/05/23 15:29:33]

Done.

+                    || fullName.size() == dir.size() + filename.size() + 1);
+    const char* basename = SkBasename(fullName.c_str());

[epoger, 2013/05/22 17:33:58]

I think the code would be easier to follow if you always used SkStrings, or
always used char *, instead of a mix.

[scroggo, 2013/05/23 15:29:33]

Done.

+    // basename should be the same as filename
+    REPORTER_ASSERT(reporter, 0 == strcmp(basename, filename.c_str()));
+    // Now take the basename of filename, which should be the same as filename.
+    basename = SkBasename(filename.c_str());
+    REPORTER_ASSERT(reporter, 0 == strcmp(basename, filename.c_str()));
+}
+
+static void test_os_path_utils_tests(skiatest::Reporter* reporter) {
+    SkString dir("dir");
+    SkString filename("file");
+    test_dir_with_file(reporter, dir, filename);
+    // Now make sure this works with a path separator at the end of dir.
+    dir.appendUnichar(SkPATH_SEPARATOR);
+    test_dir_with_file(reporter, dir, filename);
+    // Test with a sub directory.
+    dir.append("subDir");
+    test_dir_with_file(reporter, dir, filename);
+}
+
+#include "TestClassDef.h"
+DEFINE_TESTCLASS("OSPathUtils", OSPathUtilsTestClass, test_os_path_utils_tests)