diff --git a/libs/androidfw/tests/BigBuffer_test.cpp b/libs/androidfw/tests/BigBuffer_test.cpp
new file mode 100644
index 0000000..382d21e
--- /dev/null
+++ b/libs/androidfw/tests/BigBuffer_test.cpp
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "androidfw/BigBuffer.h"
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+using ::testing::NotNull;
+
+namespace android {
+
+TEST(BigBufferTest, AllocateSingleBlock) {
+  BigBuffer buffer(4);
+
+  EXPECT_THAT(buffer.NextBlock<char>(2), NotNull());
+  EXPECT_EQ(2u, buffer.size());
+}
+
+TEST(BigBufferTest, ReturnSameBlockIfNextAllocationFits) {
+  BigBuffer buffer(16);
+
+  char* b1 = buffer.NextBlock<char>(8);
+  EXPECT_THAT(b1, NotNull());
+
+  char* b2 = buffer.NextBlock<char>(4);
+  EXPECT_THAT(b2, NotNull());
+
+  EXPECT_EQ(b1 + 8, b2);
+}
+
+TEST(BigBufferTest, AllocateExactSizeBlockIfLargerThanBlockSize) {
+  BigBuffer buffer(16);
+
+  EXPECT_THAT(buffer.NextBlock<char>(32), NotNull());
+  EXPECT_EQ(32u, buffer.size());
+}
+
+TEST(BigBufferTest, AppendAndMoveBlock) {
+  BigBuffer buffer(16);
+
+  uint32_t* b1 = buffer.NextBlock<uint32_t>();
+  ASSERT_THAT(b1, NotNull());
+  *b1 = 33;
+
+  {
+    BigBuffer buffer2(16);
+    b1 = buffer2.NextBlock<uint32_t>();
+    ASSERT_THAT(b1, NotNull());
+    *b1 = 44;
+
+    buffer.AppendBuffer(std::move(buffer2));
+    EXPECT_EQ(0u, buffer2.size());  // NOLINT
+    EXPECT_EQ(buffer2.begin(), buffer2.end());
+  }
+
+  EXPECT_EQ(2 * sizeof(uint32_t), buffer.size());
+
+  auto b = buffer.begin();
+  ASSERT_NE(b, buffer.end());
+  ASSERT_EQ(sizeof(uint32_t), b->size);
+  ASSERT_EQ(33u, *reinterpret_cast<uint32_t*>(b->buffer.get()));
+  ++b;
+
+  ASSERT_NE(b, buffer.end());
+  ASSERT_EQ(sizeof(uint32_t), b->size);
+  ASSERT_EQ(44u, *reinterpret_cast<uint32_t*>(b->buffer.get()));
+  ++b;
+
+  ASSERT_EQ(b, buffer.end());
+}
+
+TEST(BigBufferTest, PadAndAlignProperly) {
+  BigBuffer buffer(16);
+
+  ASSERT_THAT(buffer.NextBlock<char>(2), NotNull());
+  ASSERT_EQ(2u, buffer.size());
+  buffer.Pad(2);
+  ASSERT_EQ(4u, buffer.size());
+  buffer.Align4();
+  ASSERT_EQ(4u, buffer.size());
+  buffer.Pad(2);
+  ASSERT_EQ(6u, buffer.size());
+  buffer.Align4();
+  ASSERT_EQ(8u, buffer.size());
+}
+
+}  // namespace android
diff --git a/libs/androidfw/tests/StringPool_test.cpp b/libs/androidfw/tests/StringPool_test.cpp
new file mode 100644
index 0000000..047d457
--- /dev/null
+++ b/libs/androidfw/tests/StringPool_test.cpp
@@ -0,0 +1,388 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "androidfw/StringPool.h"
+
+#include <string>
+
+#include "androidfw/IDiagnostics.h"
+#include "androidfw/StringPiece.h"
+#include "androidfw/Util.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+using ::android::StringPiece;
+using ::android::StringPiece16;
+using ::testing::Eq;
+using ::testing::Ne;
+using ::testing::NotNull;
+using ::testing::Pointee;
+
+namespace android {
+
+TEST(StringPoolTest, InsertOneString) {
+  StringPool pool;
+
+  StringPool::Ref ref = pool.MakeRef("wut");
+  EXPECT_THAT(*ref, Eq("wut"));
+}
+
+TEST(StringPoolTest, InsertTwoUniqueStrings) {
+  StringPool pool;
+
+  StringPool::Ref ref_a = pool.MakeRef("wut");
+  StringPool::Ref ref_b = pool.MakeRef("hey");
+
+  EXPECT_THAT(*ref_a, Eq("wut"));
+  EXPECT_THAT(*ref_b, Eq("hey"));
+}
+
+TEST(StringPoolTest, DoNotInsertNewDuplicateString) {
+  StringPool pool;
+
+  StringPool::Ref ref_a = pool.MakeRef("wut");
+  StringPool::Ref ref_b = pool.MakeRef("wut");
+
+  EXPECT_THAT(*ref_a, Eq("wut"));
+  EXPECT_THAT(*ref_b, Eq("wut"));
+  EXPECT_THAT(pool.size(), Eq(1u));
+}
+
+TEST(StringPoolTest, DoNotDedupeSameStringDifferentPriority) {
+  StringPool pool;
+
+  StringPool::Ref ref_a = pool.MakeRef("wut", StringPool::Context(0x81010001));
+  StringPool::Ref ref_b = pool.MakeRef("wut", StringPool::Context(0x81010002));
+
+  EXPECT_THAT(*ref_a, Eq("wut"));
+  EXPECT_THAT(*ref_b, Eq("wut"));
+  EXPECT_THAT(pool.size(), Eq(2u));
+}
+
+TEST(StringPoolTest, MaintainInsertionOrderIndex) {
+  StringPool pool;
+
+  StringPool::Ref ref_a = pool.MakeRef("z");
+  StringPool::Ref ref_b = pool.MakeRef("a");
+  StringPool::Ref ref_c = pool.MakeRef("m");
+
+  EXPECT_THAT(ref_a.index(), Eq(0u));
+  EXPECT_THAT(ref_b.index(), Eq(1u));
+  EXPECT_THAT(ref_c.index(), Eq(2u));
+}
+
+TEST(StringPoolTest, PruneStringsWithNoReferences) {
+  StringPool pool;
+
+  StringPool::Ref ref_a = pool.MakeRef("foo");
+
+  {
+    StringPool::Ref ref_b = pool.MakeRef("wut");
+    EXPECT_THAT(*ref_b, Eq("wut"));
+    EXPECT_THAT(pool.size(), Eq(2u));
+    pool.Prune();
+    EXPECT_THAT(pool.size(), Eq(2u));
+  }
+  EXPECT_THAT(pool.size(), Eq(2u));
+
+  {
+    StringPool::Ref ref_c = pool.MakeRef("bar");
+    EXPECT_THAT(pool.size(), Eq(3u));
+
+    pool.Prune();
+    EXPECT_THAT(pool.size(), Eq(2u));
+  }
+  EXPECT_THAT(pool.size(), Eq(2u));
+
+  pool.Prune();
+  EXPECT_THAT(pool.size(), Eq(1u));
+}
+
+TEST(StringPoolTest, SortAndMaintainIndexesInStringReferences) {
+  StringPool pool;
+
+  StringPool::Ref ref_a = pool.MakeRef("z");
+  StringPool::Ref ref_b = pool.MakeRef("a");
+  StringPool::Ref ref_c = pool.MakeRef("m");
+
+  EXPECT_THAT(*ref_a, Eq("z"));
+  EXPECT_THAT(ref_a.index(), Eq(0u));
+
+  EXPECT_THAT(*ref_b, Eq("a"));
+  EXPECT_THAT(ref_b.index(), Eq(1u));
+
+  EXPECT_THAT(*ref_c, Eq("m"));
+  EXPECT_THAT(ref_c.index(), Eq(2u));
+
+  pool.Sort();
+
+  EXPECT_THAT(*ref_a, Eq("z"));
+  EXPECT_THAT(ref_a.index(), Eq(2u));
+
+  EXPECT_THAT(*ref_b, Eq("a"));
+  EXPECT_THAT(ref_b.index(), Eq(0u));
+
+  EXPECT_THAT(*ref_c, Eq("m"));
+  EXPECT_THAT(ref_c.index(), Eq(1u));
+}
+
+TEST(StringPoolTest, SortAndStillDedupe) {
+  StringPool pool;
+
+  StringPool::Ref ref_a = pool.MakeRef("z");
+  StringPool::Ref ref_b = pool.MakeRef("a");
+  StringPool::Ref ref_c = pool.MakeRef("m");
+
+  pool.Sort();
+
+  StringPool::Ref ref_d = pool.MakeRef("z");
+  StringPool::Ref ref_e = pool.MakeRef("a");
+  StringPool::Ref ref_f = pool.MakeRef("m");
+
+  EXPECT_THAT(ref_d.index(), Eq(ref_a.index()));
+  EXPECT_THAT(ref_e.index(), Eq(ref_b.index()));
+  EXPECT_THAT(ref_f.index(), Eq(ref_c.index()));
+}
+
+TEST(StringPoolTest, AddStyles) {
+  StringPool pool;
+
+  StringPool::StyleRef ref = pool.MakeRef(StyleString{{"android"}, {Span{{"b"}, 2, 6}}});
+  EXPECT_THAT(ref.index(), Eq(0u));
+  EXPECT_THAT(ref->value, Eq("android"));
+  ASSERT_THAT(ref->spans.size(), Eq(1u));
+
+  const StringPool::Span& span = ref->spans.front();
+  EXPECT_THAT(*span.name, Eq("b"));
+  EXPECT_THAT(span.first_char, Eq(2u));
+  EXPECT_THAT(span.last_char, Eq(6u));
+}
+
+TEST(StringPoolTest, DoNotDedupeStyleWithSameStringAsNonStyle) {
+  StringPool pool;
+
+  StringPool::Ref ref = pool.MakeRef("android");
+
+  StyleString str{{"android"}, {}};
+  StringPool::StyleRef style_ref = pool.MakeRef(StyleString{{"android"}, {}});
+
+  EXPECT_THAT(ref.index(), Ne(style_ref.index()));
+}
+
+TEST(StringPoolTest, StylesAndStringsAreSeparateAfterSorting) {
+  StringPool pool;
+
+  StringPool::StyleRef ref_a = pool.MakeRef(StyleString{{"beta"}, {}});
+  StringPool::Ref ref_b = pool.MakeRef("alpha");
+  StringPool::StyleRef ref_c = pool.MakeRef(StyleString{{"alpha"}, {}});
+
+  EXPECT_THAT(ref_b.index(), Ne(ref_c.index()));
+
+  pool.Sort();
+
+  EXPECT_THAT(ref_c.index(), Eq(0u));
+  EXPECT_THAT(ref_a.index(), Eq(1u));
+  EXPECT_THAT(ref_b.index(), Eq(2u));
+}
+
+TEST(StringPoolTest, FlattenEmptyStringPoolUtf8) {
+  using namespace android;  // For NO_ERROR on Windows.
+  NoOpDiagnostics diag;
+
+  StringPool pool;
+  BigBuffer buffer(1024);
+  StringPool::FlattenUtf8(&buffer, pool, &diag);
+
+  std::unique_ptr<uint8_t[]> data = android::util::Copy(buffer);
+  ResStringPool test;
+  ASSERT_THAT(test.setTo(data.get(), buffer.size()), Eq(NO_ERROR));
+}
+
+TEST(StringPoolTest, FlattenOddCharactersUtf16) {
+  using namespace android;  // For NO_ERROR on Windows.
+  NoOpDiagnostics diag;
+
+  StringPool pool;
+  pool.MakeRef("\u093f");
+  BigBuffer buffer(1024);
+  StringPool::FlattenUtf16(&buffer, pool, &diag);
+
+  std::unique_ptr<uint8_t[]> data = android::util::Copy(buffer);
+  ResStringPool test;
+  ASSERT_EQ(test.setTo(data.get(), buffer.size()), NO_ERROR);
+  auto str = test.stringAt(0);
+  ASSERT_TRUE(str.has_value());
+  EXPECT_THAT(str->size(), Eq(1u));
+  EXPECT_THAT(str->data(), Pointee(Eq(u'\u093f')));
+  EXPECT_THAT(str->data()[1], Eq(0u));
+}
+
+constexpr const char* sLongString =
+    "バッテリーを長持ちさせるため、バッテリーセーバーは端末のパフォーマンスを抑"
+    "え、バイブレーション、位置情報サービス、大半のバックグラウンドデータを制限"
+    "します。メール、SMSや、同期を使 "
+    "用するその他のアプリは、起動しても更新されないことがあります。バッテリーセ"
+    "ーバーは端末の充電中は自動的にOFFになります。";
+
+TEST(StringPoolTest, Flatten) {
+  using namespace android;  // For NO_ERROR on Windows.
+  NoOpDiagnostics diag;
+
+  StringPool pool;
+
+  StringPool::Ref ref_a = pool.MakeRef("hello");
+  StringPool::Ref ref_b = pool.MakeRef("goodbye");
+  StringPool::Ref ref_c = pool.MakeRef(sLongString);
+  StringPool::Ref ref_d = pool.MakeRef("");
+  StringPool::StyleRef ref_e =
+      pool.MakeRef(StyleString{{"style"}, {Span{{"b"}, 0, 1}, Span{{"i"}, 2, 3}}});
+
+  // Styles are always first.
+  EXPECT_THAT(ref_e.index(), Eq(0u));
+
+  EXPECT_THAT(ref_a.index(), Eq(1u));
+  EXPECT_THAT(ref_b.index(), Eq(2u));
+  EXPECT_THAT(ref_c.index(), Eq(3u));
+  EXPECT_THAT(ref_d.index(), Eq(4u));
+
+  BigBuffer buffers[2] = {BigBuffer(1024), BigBuffer(1024)};
+  StringPool::FlattenUtf8(&buffers[0], pool, &diag);
+  StringPool::FlattenUtf16(&buffers[1], pool, &diag);
+
+  // Test both UTF-8 and UTF-16 buffers.
+  for (const BigBuffer& buffer : buffers) {
+    std::unique_ptr<uint8_t[]> data = android::util::Copy(buffer);
+
+    ResStringPool test;
+    ASSERT_EQ(test.setTo(data.get(), buffer.size()), NO_ERROR);
+
+    EXPECT_THAT(android::util::GetString(test, 1), Eq("hello"));
+    EXPECT_THAT(android::util::GetString16(test, 1), Eq(u"hello"));
+
+    EXPECT_THAT(android::util::GetString(test, 2), Eq("goodbye"));
+    EXPECT_THAT(android::util::GetString16(test, 2), Eq(u"goodbye"));
+
+    EXPECT_THAT(android::util::GetString(test, 3), Eq(sLongString));
+    EXPECT_THAT(android::util::GetString16(test, 3), Eq(util::Utf8ToUtf16(sLongString)));
+
+    EXPECT_TRUE(test.stringAt(4).has_value() || test.string8At(4).has_value());
+
+    EXPECT_THAT(android::util::GetString(test, 0), Eq("style"));
+    EXPECT_THAT(android::util::GetString16(test, 0), Eq(u"style"));
+
+    auto span_result = test.styleAt(0);
+    ASSERT_TRUE(span_result.has_value());
+
+    const ResStringPool_span* span = span_result->unsafe_ptr();
+    EXPECT_THAT(android::util::GetString(test, span->name.index), Eq("b"));
+    EXPECT_THAT(android::util::GetString16(test, span->name.index), Eq(u"b"));
+    EXPECT_THAT(span->firstChar, Eq(0u));
+    EXPECT_THAT(span->lastChar, Eq(1u));
+    span++;
+
+    ASSERT_THAT(span->name.index, Ne(ResStringPool_span::END));
+    EXPECT_THAT(android::util::GetString(test, span->name.index), Eq("i"));
+    EXPECT_THAT(android::util::GetString16(test, span->name.index), Eq(u"i"));
+    EXPECT_THAT(span->firstChar, Eq(2u));
+    EXPECT_THAT(span->lastChar, Eq(3u));
+    span++;
+
+    EXPECT_THAT(span->name.index, Eq(ResStringPool_span::END));
+  }
+}
+
+TEST(StringPoolTest, ModifiedUTF8) {
+  using namespace android;  // For NO_ERROR on Windows.
+  NoOpDiagnostics diag;
+  StringPool pool;
+  StringPool::Ref ref_a = pool.MakeRef("\xF0\x90\x90\x80");          // 𐐀 (U+10400)
+  StringPool::Ref ref_b = pool.MakeRef("foo \xF0\x90\x90\xB7 bar");  // 𐐷 (U+10437)
+  StringPool::Ref ref_c = pool.MakeRef("\xF0\x90\x90\x80\xF0\x90\x90\xB7");
+
+  BigBuffer buffer(1024);
+  StringPool::FlattenUtf8(&buffer, pool, &diag);
+  std::unique_ptr<uint8_t[]> data = android::util::Copy(buffer);
+
+  // Check that the codepoints are encoded using two three-byte surrogate pairs
+  ResStringPool test;
+  ASSERT_EQ(test.setTo(data.get(), buffer.size()), NO_ERROR);
+  auto str = test.string8At(0);
+  ASSERT_TRUE(str.has_value());
+  EXPECT_THAT(str->to_string(), Eq("\xED\xA0\x81\xED\xB0\x80"));
+
+  str = test.string8At(1);
+  ASSERT_TRUE(str.has_value());
+  EXPECT_THAT(str->to_string(), Eq("foo \xED\xA0\x81\xED\xB0\xB7 bar"));
+
+  str = test.string8At(2);
+  ASSERT_TRUE(str.has_value());
+  EXPECT_THAT(str->to_string(), Eq("\xED\xA0\x81\xED\xB0\x80\xED\xA0\x81\xED\xB0\xB7"));
+
+  // Check that retrieving the strings returns the original UTF-8 character bytes
+  EXPECT_THAT(android::util::GetString(test, 0), Eq("\xF0\x90\x90\x80"));
+  EXPECT_THAT(android::util::GetString(test, 1), Eq("foo \xF0\x90\x90\xB7 bar"));
+  EXPECT_THAT(android::util::GetString(test, 2), Eq("\xF0\x90\x90\x80\xF0\x90\x90\xB7"));
+}
+
+TEST(StringPoolTest, MaxEncodingLength) {
+  NoOpDiagnostics diag;
+  using namespace android;  // For NO_ERROR on Windows.
+  ResStringPool test;
+
+  StringPool pool;
+  pool.MakeRef("aaaaaaaaaa");
+  BigBuffer buffers[2] = {BigBuffer(1024), BigBuffer(1024)};
+
+  // Make sure a UTF-8 string under the maximum length does not produce an error
+  EXPECT_THAT(StringPool::FlattenUtf8(&buffers[0], pool, &diag), Eq(true));
+  std::unique_ptr<uint8_t[]> data = android::util::Copy(buffers[0]);
+  test.setTo(data.get(), buffers[0].size());
+  EXPECT_THAT(android::util::GetString(test, 0), Eq("aaaaaaaaaa"));
+
+  // Make sure a UTF-16 string under the maximum length does not produce an error
+  EXPECT_THAT(StringPool::FlattenUtf16(&buffers[1], pool, &diag), Eq(true));
+  data = android::util::Copy(buffers[1]);
+  test.setTo(data.get(), buffers[1].size());
+  EXPECT_THAT(android::util::GetString16(test, 0), Eq(u"aaaaaaaaaa"));
+
+  StringPool pool2;
+  std::string longStr(50000, 'a');
+  pool2.MakeRef("this fits1");
+  pool2.MakeRef(longStr);
+  pool2.MakeRef("this fits2");
+  BigBuffer buffers2[2] = {BigBuffer(1024), BigBuffer(1024)};
+
+  // Make sure a string that exceeds the maximum length of UTF-8 produces an
+  // error and writes a shorter error string instead
+  EXPECT_THAT(StringPool::FlattenUtf8(&buffers2[0], pool2, &diag), Eq(false));
+  data = android::util::Copy(buffers2[0]);
+  test.setTo(data.get(), buffers2[0].size());
+  EXPECT_THAT(android::util::GetString(test, 0), "this fits1");
+  EXPECT_THAT(android::util::GetString(test, 1), "STRING_TOO_LARGE");
+  EXPECT_THAT(android::util::GetString(test, 2), "this fits2");
+
+  // Make sure a string that a string that exceeds the maximum length of UTF-8
+  // but not UTF-16 does not error for UTF-16
+  StringPool pool3;
+  std::u16string longStr16(50000, 'a');
+  pool3.MakeRef(longStr);
+  EXPECT_THAT(StringPool::FlattenUtf16(&buffers2[1], pool3, &diag), Eq(true));
+  data = android::util::Copy(buffers2[1]);
+  test.setTo(data.get(), buffers2[1].size());
+  EXPECT_THAT(android::util::GetString16(test, 0), Eq(longStr16));
+}
+
+}  // namespace android