First pass of ImageWriter

Change-Id: I4f189587a2e3cc1c265200b8fa64321b299947eb
diff --git a/src/file_test.cc b/src/file_test.cc
new file mode 100644
index 0000000..d019d09
--- /dev/null
+++ b/src/file_test.cc
@@ -0,0 +1,47 @@
+// Copyright 2009 Google Inc. All Rights Reserved.
+
+#include "common_test.h"
+#include "file.h"
+#include "os.h"
+#include "scoped_ptr.h"
+
+#include "gtest/gtest.h"
+
+namespace art {
+
+class FileTest : public RuntimeTest {};
+
+TEST_F(FileTest, Read) {
+  std::string filename = GetLibCoreDexFileName();
+  scoped_ptr<File> file(OS::OpenBinaryFile(filename.c_str(), false));
+  ASSERT_TRUE(file != NULL);
+  EXPECT_STREQ(filename.c_str(), file->name());
+  char buffer[3];
+  buffer[0] = '\0';
+  EXPECT_TRUE(file->ReadFully(buffer, 2));  // ReadFully returns true.
+  buffer[2] = '\0';
+  EXPECT_STREQ("PK", buffer); // zip file magic
+  EXPECT_FALSE(file->WriteByte(1));  // Cannot write to a read-only file.
+}
+
+
+TEST_F(FileTest, FileLength) {
+  std::string filename = GetLibCoreDexFileName();
+  scoped_ptr<File> file(OS::OpenBinaryFile(filename.c_str(), false));
+  ASSERT_TRUE(file != NULL);
+  EXPECT_NE(0, file->Length());
+}
+
+
+TEST_F(FileTest, FilePosition) {
+  std::string filename = GetLibCoreDexFileName();
+  scoped_ptr<File> file(OS::OpenBinaryFile(filename.c_str(), false));
+  ASSERT_TRUE(file != NULL);
+  char buf[4];
+  EXPECT_TRUE(file->ReadFully(buf, 2));
+  EXPECT_EQ(2, file->Position());
+  EXPECT_TRUE(file->ReadFully(buf, 2));
+  EXPECT_EQ(4, file->Position());
+}
+
+}  // namespace art