Added basic span reader test.
Might as well right better tests when writing sorting v2. Backfilling
is needed here before we can build up further.
Change-Id: Ibe805cb031eba3eac4bb3d65dfa318c52e6487e2
diff --git a/aos/testing/tmpdir.h b/aos/testing/tmpdir.h
new file mode 100644
index 0000000..7e64342
--- /dev/null
+++ b/aos/testing/tmpdir.h
@@ -0,0 +1,15 @@
+#ifndef AOS_TESTING_TMPDIR_H_
+#define AOS_TESTING_TMPDIR_H_
+
+#include <string>
+
+namespace aos {
+namespace testing {
+
+// Returns a usable temporary directory.
+std::string TestTmpDir();
+
+} // namespace testing
+} // namespace aos
+
+#endif // AOS_TESTING_TMPDIR_H_