diff --git a/cc/tidy_test.go b/cc/tidy_test.go
new file mode 100644
index 0000000..339b302
--- /dev/null
+++ b/cc/tidy_test.go
@@ -0,0 +1,98 @@
+// Copyright 2022 Google Inc. All rights reserved.
+//
+// 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.
+
+package cc
+
+import (
+	"fmt"
+	"testing"
+
+	"android/soong/android"
+)
+
+func TestWithTidy(t *testing.T) {
+	// When WITH_TIDY=1 or (ALLOW_LOCAL_TIDY_TRUE=1 and local tidy:true)
+	// a C++ library should depend on .tidy files.
+	testCases := []struct {
+		withTidy, allowLocalTidyTrue string // "_" means undefined
+		needTidyFile                 []bool // for {libfoo_0, libfoo_1} and {libbar_0, libbar_1}
+	}{
+		{"_", "_", []bool{false, false, false}},
+		{"_", "0", []bool{false, false, false}},
+		{"_", "1", []bool{false, true, false}},
+		{"_", "true", []bool{false, true, false}},
+		{"0", "_", []bool{false, false, false}},
+		{"0", "1", []bool{false, true, false}},
+		{"1", "_", []bool{true, true, false}},
+		{"1", "false", []bool{true, true, false}},
+		{"1", "1", []bool{true, true, false}},
+		{"true", "_", []bool{true, true, false}},
+	}
+	bp := `
+		cc_library_shared {
+			name: "libfoo_0", // depends on .tidy if WITH_TIDY=1
+			srcs: ["foo.c"],
+		}
+		cc_library_shared { // depends on .tidy if WITH_TIDY=1 or ALLOW_LOCAL_TIDY_TRUE=1
+			name: "libfoo_1",
+			srcs: ["foo.c"],
+			tidy: true,
+		}
+		cc_library_shared { // no .tidy
+			name: "libfoo_2",
+			srcs: ["foo.c"],
+			tidy: false,
+		}
+		cc_library_static {
+			name: "libbar_0", // depends on .tidy if WITH_TIDY=1
+			srcs: ["bar.c"],
+		}
+		cc_library_static { // depends on .tidy if WITH_TIDY=1 or ALLOW_LOCAL_TIDY_TRUE=1
+			name: "libbar_1",
+			srcs: ["bar.c"],
+			tidy: true,
+		}
+		cc_library_static { // no .tidy
+			name: "libbar_2",
+			srcs: ["bar.c"],
+			tidy: false,
+		}`
+	for index, test := range testCases {
+		testName := fmt.Sprintf("case%d,%v,%v", index, test.withTidy, test.allowLocalTidyTrue)
+		t.Run(testName, func(t *testing.T) {
+			testEnv := map[string]string{}
+			if test.withTidy != "_" {
+				testEnv["WITH_TIDY"] = test.withTidy
+			}
+			if test.allowLocalTidyTrue != "_" {
+				testEnv["ALLOW_LOCAL_TIDY_TRUE"] = test.allowLocalTidyTrue
+			}
+			ctx := android.GroupFixturePreparers(prepareForCcTest, android.FixtureMergeEnv(testEnv)).RunTestWithBp(t, bp)
+			for n := 0; n < 3; n++ {
+				checkLibraryRule := func(foo, variant, ruleName string) {
+					libName := fmt.Sprintf("lib%s_%d", foo, n)
+					tidyFile := "out/soong/.intermediates/" + libName + "/" + variant + "/obj/" + foo + ".tidy"
+					depFiles := ctx.ModuleForTests(libName, variant).Rule(ruleName).Validations.Strings()
+					if test.needTidyFile[n] {
+						android.AssertStringListContains(t, libName+" needs .tidy file", depFiles, tidyFile)
+					} else {
+						android.AssertStringListDoesNotContain(t, libName+" does not need .tidy file", depFiles, tidyFile)
+					}
+				}
+				checkLibraryRule("foo", "android_arm64_armv8-a_shared", "ld")
+				checkLibraryRule("bar", "android_arm64_armv8-a_static", "ar")
+			}
+		})
+	}
+}