Add unittest for the PatchWriter.

Split the unittest logic between bsdiff() function and the PatchWriter.
This patch now tests individually the PatchWriter logic that writes to
disk and the bsdiff() logic to create patches in the same very simple
cases.

We also update the Android.bp file to only pass -DBSDIFF_TARGET_UNITTEST
when building for the target.

Bug: 34220646
Test: ran unittests.

Change-Id: I9350157ee4a0b5a617f44bb187bd7652f6d6f017

1 files changed, 110 insertions, 0 deletions

diff --git a/patch_writer_unittest.cc b/patch_writer_unittest.cc
new file mode 100644
index 0000000..24a8552
--- /dev/null
+++ b/patch_writer_unittest.cc
@@ -0,0 +1,110 @@
+// Copyright 2017 The Chromium OS 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 "bsdiff/patch_writer.h"
+
+#include <gtest/gtest.h>
+
+#include "bsdiff/test_utils.h"
+
+namespace {
+
+// Generated with:
+// echo 'Hello World' | hexdump -v -e '"    " 12/1 "0x%02x, " "\n"'
+const uint8_t kHelloWorld[] = {
+    0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x20, 0x57, 0x6f, 0x72, 0x6c, 0x64, 0x0a,
+};
+
+// Compressed empty file.
+// bzip2 -9 </dev/null | hexdump -v -e '"    " 7/1 "0x%02x, " "\n"'
+const uint8_t kCompressedEmpty[] = {0x42, 0x5a, 0x68, 0x39, 0x17, 0x72, 0x45,
+                                    0x38, 0x50, 0x90, 0x00, 0x00, 0x00, 0x00};
+
+// echo 'Hello World' | bzip2 -9 | hexdump -v -e '"    " 12/1 "0x%02x, " "\n"'
+const uint8_t kCompressedHelloWorld[] = {
+    0x42, 0x5a, 0x68, 0x39, 0x31, 0x41, 0x59, 0x26, 0x53, 0x59, 0xd8, 0x72,
+    0x01, 0x2f, 0x00, 0x00, 0x01, 0x57, 0x80, 0x00, 0x10, 0x40, 0x00, 0x00,
+    0x40, 0x00, 0x80, 0x06, 0x04, 0x90, 0x00, 0x20, 0x00, 0x22, 0x06, 0x86,
+    0xd4, 0x20, 0xc9, 0x88, 0xc7, 0x69, 0xe8, 0x28, 0x1f, 0x8b, 0xb9, 0x22,
+    0x9c, 0x28, 0x48, 0x6c, 0x39, 0x00, 0x97, 0x80,
+};
+
+// Compressed a buffer of zeros of the same length of the kHelloWorld.
+// head -c `echo 'Hello World' | wc -c` /dev/zero | bzip2 -9 |
+//   hexdump -v -e '"    " 10/1 "0x%02x, " "\n"'
+const uint8_t kCompressedZeros[] = {
+    0x42, 0x5a, 0x68, 0x39, 0x31, 0x41, 0x59, 0x26, 0x53, 0x59,
+    0xf6, 0x63, 0xab, 0xde, 0x00, 0x00, 0x00, 0x40, 0x00, 0x40,
+    0x40, 0x20, 0x00, 0x21, 0x00, 0x82, 0x83, 0x17, 0x72, 0x45,
+    0x38, 0x50, 0x90, 0xf6, 0x63, 0xab, 0xde,
+};
+
+}  // namespace
+
+namespace bsdiff {
+
+class BsdiffPatchWriterTest : public testing::Test {
+ protected:
+  test_utils::ScopedTempFile patch_file_{"bsdiff_newfile.XXXXXX"};
+  BsdiffPatchWriter patch_writer_{patch_file_.filename()};
+};
+
+TEST_F(BsdiffPatchWriterTest, CreateEmptyPatchTest) {
+  EXPECT_TRUE(patch_writer_.InitializeBuffers(nullptr, 0, nullptr, 0));
+  EXPECT_TRUE(patch_writer_.Close());
+
+  test_utils::BsdiffPatchFile patch;
+  EXPECT_TRUE(patch.LoadFromFile(patch_file_.filename()));
+  EXPECT_TRUE(patch.IsValid());
+
+  // An empty bz2 file will have 14 bytes.
+  EXPECT_EQ(sizeof(kCompressedEmpty), static_cast<uint64_t>(patch.diff_len));
+  EXPECT_EQ(sizeof(kCompressedEmpty), patch.extra_len);
+}
+
+TEST_F(BsdiffPatchWriterTest, AllInExtraStreamTest) {
+  EXPECT_TRUE(patch_writer_.InitializeBuffers(
+      nullptr, 0, kHelloWorld, sizeof(kHelloWorld)));
+  // Write to the extra stream in two parts: first 5 bytes, then the rest.
+  EXPECT_TRUE(patch_writer_.AddControlEntry(ControlEntry(0, 5, 0)));
+  EXPECT_TRUE(patch_writer_.AddControlEntry(
+      ControlEntry(0, sizeof(kHelloWorld) - 5, 0)));
+  EXPECT_TRUE(patch_writer_.Close());
+
+  test_utils::BsdiffPatchFile patch;
+  EXPECT_TRUE(patch.LoadFromFile(patch_file_.filename()));
+  EXPECT_TRUE(patch.IsValid());
+  EXPECT_EQ(patch.bz2_diff,
+            std::vector<uint8_t>(kCompressedEmpty,
+                                 kCompressedEmpty + sizeof(kCompressedEmpty)));
+  EXPECT_EQ(patch.bz2_extra,
+            std::vector<uint8_t>(
+                kCompressedHelloWorld,
+                kCompressedHelloWorld + sizeof(kCompressedHelloWorld)));
+
+  EXPECT_EQ(static_cast<int64_t>(sizeof(kHelloWorld)), patch.new_file_len);
+}
+
+TEST_F(BsdiffPatchWriterTest, AllInDiffStreamTest) {
+  EXPECT_TRUE(patch_writer_.InitializeBuffers(
+      kHelloWorld, sizeof(kHelloWorld), kHelloWorld, sizeof(kHelloWorld)));
+  // Write to the extra stream in two parts: first 5 bytes, then the rest.
+  EXPECT_TRUE(
+      patch_writer_.AddControlEntry(ControlEntry(sizeof(kHelloWorld), 0, 0)));
+  EXPECT_TRUE(patch_writer_.Close());
+
+  test_utils::BsdiffPatchFile patch;
+  EXPECT_TRUE(patch.LoadFromFile(patch_file_.filename()));
+  EXPECT_TRUE(patch.IsValid());
+  EXPECT_EQ(patch.bz2_extra,
+            std::vector<uint8_t>(kCompressedEmpty,
+                                 kCompressedEmpty + sizeof(kCompressedEmpty)));
+  EXPECT_EQ(patch.bz2_diff,
+            std::vector<uint8_t>(kCompressedZeros,
+                                 kCompressedZeros + sizeof(kCompressedZeros)));
+
+  EXPECT_EQ(static_cast<int64_t>(sizeof(kHelloWorld)), patch.new_file_len);
+}
+
+}  // namespace bsdiff