diff --git a/src/tint/utils/unique_vector_test.cc b/src/tint/utils/unique_vector_test.cc
new file mode 100644
index 0000000..892282b
--- /dev/null
+++ b/src/tint/utils/unique_vector_test.cc
@@ -0,0 +1,145 @@
+// Copyright 2021 The Tint Authors.
+//
+// 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 "src/tint/utils/unique_vector.h"
+#include "src/tint/utils/reverse.h"
+
+#include "gtest/gtest.h"
+
+namespace tint {
+namespace utils {
+namespace {
+
+TEST(UniqueVectorTest, Empty) {
+  UniqueVector<int> unique_vec;
+  EXPECT_EQ(unique_vec.size(), 0u);
+  EXPECT_EQ(unique_vec.empty(), true);
+  EXPECT_EQ(unique_vec.begin(), unique_vec.end());
+}
+
+TEST(UniqueVectorTest, MoveConstructor) {
+  UniqueVector<int> unique_vec(std::vector<int>{0, 3, 2, 1, 2});
+  EXPECT_EQ(unique_vec.size(), 4u);
+  EXPECT_EQ(unique_vec.empty(), false);
+  EXPECT_EQ(unique_vec[0], 0);
+  EXPECT_EQ(unique_vec[1], 3);
+  EXPECT_EQ(unique_vec[2], 2);
+  EXPECT_EQ(unique_vec[3], 1);
+}
+
+TEST(UniqueVectorTest, AddUnique) {
+  UniqueVector<int> unique_vec;
+  unique_vec.add(0);
+  unique_vec.add(1);
+  unique_vec.add(2);
+  EXPECT_EQ(unique_vec.size(), 3u);
+  EXPECT_EQ(unique_vec.empty(), false);
+  int i = 0;
+  for (auto n : unique_vec) {
+    EXPECT_EQ(n, i);
+    i++;
+  }
+  for (auto n : Reverse(unique_vec)) {
+    i--;
+    EXPECT_EQ(n, i);
+  }
+  EXPECT_EQ(unique_vec[0], 0);
+  EXPECT_EQ(unique_vec[1], 1);
+  EXPECT_EQ(unique_vec[2], 2);
+}
+
+TEST(UniqueVectorTest, AddDuplicates) {
+  UniqueVector<int> unique_vec;
+  unique_vec.add(0);
+  unique_vec.add(0);
+  unique_vec.add(0);
+  unique_vec.add(1);
+  unique_vec.add(1);
+  unique_vec.add(2);
+  EXPECT_EQ(unique_vec.size(), 3u);
+  EXPECT_EQ(unique_vec.empty(), false);
+  int i = 0;
+  for (auto n : unique_vec) {
+    EXPECT_EQ(n, i);
+    i++;
+  }
+  for (auto n : Reverse(unique_vec)) {
+    i--;
+    EXPECT_EQ(n, i);
+  }
+  EXPECT_EQ(unique_vec[0], 0);
+  EXPECT_EQ(unique_vec[1], 1);
+  EXPECT_EQ(unique_vec[2], 2);
+}
+
+TEST(UniqueVectorTest, AsVector) {
+  UniqueVector<int> unique_vec;
+  unique_vec.add(0);
+  unique_vec.add(0);
+  unique_vec.add(0);
+  unique_vec.add(1);
+  unique_vec.add(1);
+  unique_vec.add(2);
+
+  const std::vector<int>& vec = unique_vec;
+  EXPECT_EQ(vec.size(), 3u);
+  EXPECT_EQ(unique_vec.empty(), false);
+  int i = 0;
+  for (auto n : vec) {
+    EXPECT_EQ(n, i);
+    i++;
+  }
+  for (auto n : Reverse(unique_vec)) {
+    i--;
+    EXPECT_EQ(n, i);
+  }
+}
+
+TEST(UniqueVectorTest, PopBack) {
+  UniqueVector<int> unique_vec;
+  unique_vec.add(0);
+  unique_vec.add(2);
+  unique_vec.add(1);
+
+  EXPECT_EQ(unique_vec.pop_back(), 1);
+  EXPECT_EQ(unique_vec.size(), 2u);
+  EXPECT_EQ(unique_vec.empty(), false);
+  EXPECT_EQ(unique_vec[0], 0);
+  EXPECT_EQ(unique_vec[1], 2);
+
+  EXPECT_EQ(unique_vec.pop_back(), 2);
+  EXPECT_EQ(unique_vec.size(), 1u);
+  EXPECT_EQ(unique_vec.empty(), false);
+  EXPECT_EQ(unique_vec[0], 0);
+
+  unique_vec.add(1);
+
+  EXPECT_EQ(unique_vec.size(), 2u);
+  EXPECT_EQ(unique_vec.empty(), false);
+  EXPECT_EQ(unique_vec[0], 0);
+  EXPECT_EQ(unique_vec[1], 1);
+
+  EXPECT_EQ(unique_vec.pop_back(), 1);
+  EXPECT_EQ(unique_vec.size(), 1u);
+  EXPECT_EQ(unique_vec.empty(), false);
+  EXPECT_EQ(unique_vec[0], 0);
+
+  EXPECT_EQ(unique_vec.pop_back(), 0);
+  EXPECT_EQ(unique_vec.size(), 0u);
+  EXPECT_EQ(unique_vec.empty(), true);
+}
+
+}  // namespace
+}  // namespace utils
+}  // namespace tint