diff --git a/src/transform/calculate_array_length_test.cc b/src/transform/calculate_array_length_test.cc
new file mode 100644
index 0000000..42b2f10
--- /dev/null
+++ b/src/transform/calculate_array_length_test.cc
@@ -0,0 +1,284 @@
+// 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/transform/calculate_array_length.h"
+
+#include "src/transform/test_helper.h"
+
+namespace tint {
+namespace transform {
+namespace {
+
+using CalculateArrayLengthTest = TransformTest;
+
+TEST_F(CalculateArrayLengthTest, Basic) {
+  auto* src = R"(
+[[block]]
+struct SB {
+  x : i32;
+  arr : array<i32>;
+};
+
+var<storage> sb : SB;
+
+[[stage(vertex)]]
+fn main() {
+  var len : u32 = arrayLength(sb.arr);
+}
+)";
+
+  auto* expect = R"(
+[[block]]
+struct SB {
+  x : i32;
+  arr : array<i32>;
+};
+
+[[internal(intrinsic_buffer_size)]]
+fn tint_symbol_1(buffer : SB, result : ptr<function, u32>)
+
+var<storage> sb : SB;
+
+[[stage(vertex)]]
+fn main() {
+  var tint_symbol_7 : u32 = 0u;
+  tint_symbol_1(sb, tint_symbol_7);
+  let tint_symbol_9 : u32 = ((tint_symbol_7 - 4u) / 4u);
+  var len : u32 = tint_symbol_9;
+}
+)";
+
+  auto got = Run<CalculateArrayLength>(src);
+
+  EXPECT_EQ(expect, str(got));
+}
+
+TEST_F(CalculateArrayLengthTest, InSameBlock) {
+  auto* src = R"(
+[[block]]
+struct SB {
+  x : i32;
+  arr : array<i32>;
+};
+
+var<storage> sb : SB;
+
+[[stage(vertex)]]
+fn main() {
+  var a : u32 = arrayLength(sb.arr);
+  var b : u32 = arrayLength(sb.arr);
+  var c : u32 = arrayLength(sb.arr);
+}
+)";
+
+  auto* expect = R"(
+[[block]]
+struct SB {
+  x : i32;
+  arr : array<i32>;
+};
+
+[[internal(intrinsic_buffer_size)]]
+fn tint_symbol_1(buffer : SB, result : ptr<function, u32>)
+
+var<storage> sb : SB;
+
+[[stage(vertex)]]
+fn main() {
+  var tint_symbol_7 : u32 = 0u;
+  tint_symbol_1(sb, tint_symbol_7);
+  let tint_symbol_9 : u32 = ((tint_symbol_7 - 4u) / 4u);
+  var a : u32 = tint_symbol_9;
+  var b : u32 = tint_symbol_9;
+  var c : u32 = tint_symbol_9;
+}
+)";
+
+  auto got = Run<CalculateArrayLength>(src);
+
+  EXPECT_EQ(expect, str(got));
+}
+
+TEST_F(CalculateArrayLengthTest, WithStride) {
+  auto* src = R"(
+[[block]]
+struct SB {
+  x : i32;
+  y : f32;
+  arr : [[stride(64)]] array<i32>;
+};
+
+var<storage> sb : SB;
+
+[[stage(vertex)]]
+fn main() {
+  var len : u32 = arrayLength(sb.arr);
+}
+)";
+
+  auto* expect = R"(
+[[block]]
+struct SB {
+  x : i32;
+  y : f32;
+  arr : [[stride(64)]] array<i32>;
+};
+
+[[internal(intrinsic_buffer_size)]]
+fn tint_symbol_1(buffer : SB, result : ptr<function, u32>)
+
+var<storage> sb : SB;
+
+[[stage(vertex)]]
+fn main() {
+  var tint_symbol_8 : u32 = 0u;
+  tint_symbol_1(sb, tint_symbol_8);
+  let tint_symbol_10 : u32 = ((tint_symbol_8 - 8u) / 64u);
+  var len : u32 = tint_symbol_10;
+}
+)";
+
+  auto got = Run<CalculateArrayLength>(src);
+
+  EXPECT_EQ(expect, str(got));
+}
+
+TEST_F(CalculateArrayLengthTest, Nested) {
+  auto* src = R"(
+[[block]]
+struct SB {
+  x : i32;
+  arr : array<i32>;
+};
+
+var<storage> sb : SB;
+
+[[stage(vertex)]]
+fn main() {
+  if (true) {
+    var len : u32 = arrayLength(sb.arr);
+  } else {
+    if (true) {
+      var len : u32 = arrayLength(sb.arr);
+    }
+  }
+}
+)";
+
+  auto* expect = R"(
+[[block]]
+struct SB {
+  x : i32;
+  arr : array<i32>;
+};
+
+[[internal(intrinsic_buffer_size)]]
+fn tint_symbol_1(buffer : SB, result : ptr<function, u32>)
+
+var<storage> sb : SB;
+
+[[stage(vertex)]]
+fn main() {
+  if (true) {
+    var tint_symbol_7 : u32 = 0u;
+    tint_symbol_1(sb, tint_symbol_7);
+    let tint_symbol_9 : u32 = ((tint_symbol_7 - 4u) / 4u);
+    var len : u32 = tint_symbol_9;
+  } else {
+    if (true) {
+      var tint_symbol_10 : u32 = 0u;
+      tint_symbol_1(sb, tint_symbol_10);
+      let tint_symbol_11 : u32 = ((tint_symbol_10 - 4u) / 4u);
+      var len : u32 = tint_symbol_11;
+    }
+  }
+}
+)";
+
+  auto got = Run<CalculateArrayLength>(src);
+
+  EXPECT_EQ(expect, str(got));
+}
+
+TEST_F(CalculateArrayLengthTest, MultipleStorageBuffers) {
+  auto* src = R"(
+[[block]]
+struct SB1 {
+  x : i32;
+  arr1 : array<i32>;
+};
+
+[[block]]
+struct SB2 {
+  x : i32;
+  arr2 : array<vec4<f32>>;
+};
+
+var<storage> sb1 : SB1;
+
+var<storage> sb2 : SB2;
+
+[[stage(vertex)]]
+fn main() {
+  var len1 : u32 = arrayLength(sb1.arr1);
+  var len2 : u32 = arrayLength(sb2.arr2);
+  var x : u32 = (len1 + len2);
+}
+)";
+
+  auto* expect = R"(
+[[block]]
+struct SB1 {
+  x : i32;
+  arr1 : array<i32>;
+};
+
+[[internal(intrinsic_buffer_size)]]
+fn tint_symbol_1(buffer : SB1, result : ptr<function, u32>)
+
+[[block]]
+struct SB2 {
+  x : i32;
+  arr2 : array<vec4<f32>>;
+};
+
+[[internal(intrinsic_buffer_size)]]
+fn tint_symbol_10(buffer : SB2, result : ptr<function, u32>)
+
+var<storage> sb1 : SB1;
+
+var<storage> sb2 : SB2;
+
+[[stage(vertex)]]
+fn main() {
+  var tint_symbol_7 : u32 = 0u;
+  tint_symbol_1(sb1, tint_symbol_7);
+  let tint_symbol_9 : u32 = ((tint_symbol_7 - 4u) / 4u);
+  var tint_symbol_13 : u32 = 0u;
+  tint_symbol_10(sb2, tint_symbol_13);
+  let tint_symbol_15 : u32 = ((tint_symbol_13 - 16u) / 16u);
+  var len1 : u32 = tint_symbol_9;
+  var len2 : u32 = tint_symbol_15;
+  var x : u32 = (len1 + len2);
+}
+)";
+
+  auto got = Run<CalculateArrayLength>(src);
+
+  EXPECT_EQ(expect, str(got));
+}
+
+}  // namespace
+}  // namespace transform
+}  // namespace tint