diff --git a/test/unittests/interpreter/constant-array-builder-unittest.cc b/test/unittests/interpreter/constant-array-builder-unittest.cc
new file mode 100644
index 0000000..ea5d1bb
--- /dev/null
+++ b/test/unittests/interpreter/constant-array-builder-unittest.cc
@@ -0,0 +1,225 @@
+// Copyright 2014 the V8 project 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 "src/v8.h"
+
+#include "src/factory.h"
+#include "src/handles-inl.h"
+#include "src/interpreter/constant-array-builder.h"
+#include "src/isolate.h"
+#include "test/unittests/test-utils.h"
+
+namespace v8 {
+namespace internal {
+namespace interpreter {
+
+class ConstantArrayBuilderTest : public TestWithIsolateAndZone {
+ public:
+  ConstantArrayBuilderTest() {}
+  ~ConstantArrayBuilderTest() override {}
+
+  static const size_t kLowCapacity = ConstantArrayBuilder::kLowCapacity;
+  static const size_t kMaxCapacity = ConstantArrayBuilder::kMaxCapacity;
+};
+
+
+STATIC_CONST_MEMBER_DEFINITION const size_t
+    ConstantArrayBuilderTest::kMaxCapacity;
+STATIC_CONST_MEMBER_DEFINITION const size_t
+    ConstantArrayBuilderTest::kLowCapacity;
+
+
+TEST_F(ConstantArrayBuilderTest, AllocateAllEntries) {
+  ConstantArrayBuilder builder(isolate(), zone());
+  for (size_t i = 0; i < kMaxCapacity; i++) {
+    Handle<Object> object = isolate()->factory()->NewNumberFromSize(i);
+    builder.Insert(object);
+    CHECK_EQ(builder.size(), i + 1);
+    CHECK(builder.At(i)->SameValue(*object));
+  }
+  for (size_t i = 0; i < kMaxCapacity; i++) {
+    CHECK_EQ(Handle<Smi>::cast(builder.At(i))->value(), static_cast<double>(i));
+  }
+}
+
+
+TEST_F(ConstantArrayBuilderTest, AllocateEntriesWithIdx8Reservations) {
+  for (size_t reserved = 1; reserved < kLowCapacity; reserved *= 3) {
+    ConstantArrayBuilder builder(isolate(), zone());
+    for (size_t i = 0; i < reserved; i++) {
+      OperandSize operand_size = builder.CreateReservedEntry();
+      CHECK(operand_size == OperandSize::kByte);
+    }
+    for (size_t i = 0; i < 2 * kLowCapacity; i++) {
+      Handle<Object> object = isolate()->factory()->NewNumberFromSize(i);
+      builder.Insert(object);
+      if (i + reserved < kLowCapacity) {
+        CHECK_LE(builder.size(), kLowCapacity);
+        CHECK_EQ(builder.size(), i + 1);
+        CHECK(builder.At(i)->SameValue(*object));
+      } else {
+        CHECK_GE(builder.size(), kLowCapacity);
+        CHECK_EQ(builder.size(), i + reserved + 1);
+        CHECK(builder.At(i + reserved)->SameValue(*object));
+      }
+    }
+    CHECK_EQ(builder.size(), 2 * kLowCapacity + reserved);
+
+    // Check reserved values represented by the hole.
+    for (size_t i = 0; i < reserved; i++) {
+      Handle<Object> empty = builder.At(kLowCapacity - reserved + i);
+      CHECK(empty->SameValue(isolate()->heap()->the_hole_value()));
+    }
+
+    // Commmit reserved entries with duplicates and check size does not change.
+    DCHECK_EQ(reserved + 2 * kLowCapacity, builder.size());
+    size_t duplicates_in_idx8_space =
+        std::min(reserved, kLowCapacity - reserved);
+    for (size_t i = 0; i < duplicates_in_idx8_space; i++) {
+      builder.CommitReservedEntry(OperandSize::kByte,
+                                  isolate()->factory()->NewNumberFromSize(i));
+      DCHECK_EQ(reserved + 2 * kLowCapacity, builder.size());
+    }
+
+    // Check all committed values match expected (holes where
+    // duplicates_in_idx8_space allocated).
+    for (size_t i = 0; i < kLowCapacity - reserved; i++) {
+      Smi* smi = Smi::FromInt(static_cast<int>(i));
+      CHECK(Handle<Smi>::cast(builder.At(i))->SameValue(smi));
+    }
+    for (size_t i = kLowCapacity; i < 2 * kLowCapacity + reserved; i++) {
+      Smi* smi = Smi::FromInt(static_cast<int>(i - reserved));
+      CHECK(Handle<Smi>::cast(builder.At(i))->SameValue(smi));
+    }
+    for (size_t i = 0; i < reserved; i++) {
+      size_t index = kLowCapacity - reserved + i;
+      CHECK(builder.At(index)->IsTheHole());
+    }
+
+    // Now make reservations, and commit them with unique entries.
+    for (size_t i = 0; i < duplicates_in_idx8_space; i++) {
+      OperandSize operand_size = builder.CreateReservedEntry();
+      CHECK(operand_size == OperandSize::kByte);
+    }
+    for (size_t i = 0; i < duplicates_in_idx8_space; i++) {
+      Handle<Object> object =
+          isolate()->factory()->NewNumberFromSize(2 * kLowCapacity + i);
+      size_t index = builder.CommitReservedEntry(OperandSize::kByte, object);
+      CHECK_EQ(static_cast<int>(index), kLowCapacity - reserved + i);
+      CHECK(builder.At(static_cast<int>(index))->SameValue(*object));
+    }
+    CHECK_EQ(builder.size(), 2 * kLowCapacity + reserved);
+  }
+}
+
+
+TEST_F(ConstantArrayBuilderTest, AllocateEntriesWithIdx16Reservations) {
+  for (size_t reserved = 1; reserved < kLowCapacity; reserved *= 3) {
+    ConstantArrayBuilder builder(isolate(), zone());
+    for (size_t i = 0; i < kLowCapacity; i++) {
+      Handle<Object> object = isolate()->factory()->NewNumberFromSize(i);
+      builder.Insert(object);
+      CHECK(builder.At(i)->SameValue(*object));
+      CHECK_EQ(builder.size(), i + 1);
+    }
+    for (size_t i = 0; i < reserved; i++) {
+      OperandSize operand_size = builder.CreateReservedEntry();
+      CHECK(operand_size == OperandSize::kShort);
+      CHECK_EQ(builder.size(), kLowCapacity);
+    }
+    for (size_t i = 0; i < reserved; i++) {
+      builder.DiscardReservedEntry(OperandSize::kShort);
+      CHECK_EQ(builder.size(), kLowCapacity);
+    }
+    for (size_t i = 0; i < reserved; i++) {
+      OperandSize operand_size = builder.CreateReservedEntry();
+      CHECK(operand_size == OperandSize::kShort);
+      Handle<Object> object = isolate()->factory()->NewNumberFromSize(i);
+      builder.CommitReservedEntry(operand_size, object);
+      CHECK_EQ(builder.size(), kLowCapacity);
+    }
+    for (size_t i = kLowCapacity; i < kLowCapacity + reserved; i++) {
+      OperandSize operand_size = builder.CreateReservedEntry();
+      CHECK(operand_size == OperandSize::kShort);
+      Handle<Object> object = isolate()->factory()->NewNumberFromSize(i);
+      builder.CommitReservedEntry(operand_size, object);
+      CHECK_EQ(builder.size(), i + 1);
+    }
+  }
+}
+
+
+TEST_F(ConstantArrayBuilderTest, ToFixedArray) {
+  ConstantArrayBuilder builder(isolate(), zone());
+  static const size_t kNumberOfElements = 37;
+  for (size_t i = 0; i < kNumberOfElements; i++) {
+    Handle<Object> object = isolate()->factory()->NewNumberFromSize(i);
+    builder.Insert(object);
+    CHECK(builder.At(i)->SameValue(*object));
+  }
+  Handle<FixedArray> constant_array =
+      builder.ToFixedArray(isolate()->factory());
+  CHECK_EQ(constant_array->length(), kNumberOfElements);
+  for (size_t i = 0; i < kNumberOfElements; i++) {
+    CHECK(constant_array->get(static_cast<int>(i))->SameValue(*builder.At(i)));
+  }
+}
+
+
+TEST_F(ConstantArrayBuilderTest, GapFilledWhenLowReservationCommitted) {
+  ConstantArrayBuilder builder(isolate(), zone());
+  for (size_t i = 0; i < kLowCapacity; i++) {
+    OperandSize operand_size = builder.CreateReservedEntry();
+    CHECK(OperandSize::kByte == operand_size);
+    CHECK_EQ(builder.size(), 0);
+  }
+  for (size_t i = 0; i < kLowCapacity; i++) {
+    Handle<Object> object = isolate()->factory()->NewNumberFromSize(i);
+    builder.Insert(object);
+    CHECK_EQ(builder.size(), i + kLowCapacity + 1);
+  }
+  for (size_t i = 0; i < kLowCapacity; i++) {
+    builder.CommitReservedEntry(OperandSize::kByte,
+                                builder.At(i + kLowCapacity));
+    CHECK_EQ(builder.size(), 2 * kLowCapacity);
+  }
+  for (size_t i = 0; i < kLowCapacity; i++) {
+    Handle<Object> original = builder.At(kLowCapacity + i);
+    Handle<Object> duplicate = builder.At(i);
+    CHECK(original->SameValue(*duplicate));
+    Handle<Object> reference = isolate()->factory()->NewNumberFromSize(i);
+    CHECK(original->SameValue(*reference));
+  }
+}
+
+
+TEST_F(ConstantArrayBuilderTest, GapNotFilledWhenLowReservationDiscarded) {
+  ConstantArrayBuilder builder(isolate(), zone());
+  for (size_t i = 0; i < kLowCapacity; i++) {
+    OperandSize operand_size = builder.CreateReservedEntry();
+    CHECK(OperandSize::kByte == operand_size);
+    CHECK_EQ(builder.size(), 0);
+  }
+  for (size_t i = 0; i < kLowCapacity; i++) {
+    Handle<Object> object = isolate()->factory()->NewNumberFromSize(i);
+    builder.Insert(object);
+    CHECK_EQ(builder.size(), i + kLowCapacity + 1);
+  }
+  for (size_t i = 0; i < kLowCapacity; i++) {
+    builder.DiscardReservedEntry(OperandSize::kByte);
+    builder.Insert(builder.At(i + kLowCapacity));
+    CHECK_EQ(builder.size(), 2 * kLowCapacity);
+  }
+  for (size_t i = 0; i < kLowCapacity; i++) {
+    Handle<Object> reference = isolate()->factory()->NewNumberFromSize(i);
+    Handle<Object> original = builder.At(kLowCapacity + i);
+    CHECK(original->SameValue(*reference));
+    Handle<Object> duplicate = builder.At(i);
+    CHECK(duplicate->SameValue(*isolate()->factory()->the_hole_value()));
+  }
+}
+
+}  // namespace interpreter
+}  // namespace internal
+}  // namespace v8