check-flagged-apis: add unit test infrastructure

Add scaffolding for unit tests.

Bug: 334870672
Test: atest --host check-flagged-apis-test
Change-Id: I5ccf2a6424c19e739923379cdc41c359388484da

tools/check-flagged-apis/Android.bp

@@ -13,16 +13,37 @@
 // limitations under the License.
 
 package {
+    default_team: "trendy_team_updatable_sdk_apis",
     default_applicable_licenses: ["Android-Apache-2.0"],
 }
 
-java_binary_host {
+java_defaults {
-    name: "check-flagged-apis",
+    name: "check-flagged-apis-defaults",
     srcs: [
-        "src/**/*.kt",
+        "src/com/android/checkflaggedapis/Main.kt",
     ],
     static_libs: [
         "metalava-tools-common-m2-deps",
     ],
+}
+
+java_binary_host {
+    name: "check-flagged-apis",
+    defaults: [
+        "check-flagged-apis-defaults",
+    ],
     main_class: "com.android.checkflaggedapis.Main",
 }
+
+java_test_host {
+    name: "check-flagged-apis-test",
+    defaults: [
+        "check-flagged-apis-defaults",
+    ],
+    srcs: [
+        "src/com/android/checkflaggedapis/CheckFlaggedApisTest.kt",
+    ],
+    static_libs: [
+        "tradefed",
+    ],
+}

tools/check-flagged-apis/src/com/android/checkflaggedapis/CheckFlaggedApisTest.kt

@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2024 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.
+ */
+package com.android.checkflaggedapis
+
+import com.android.tradefed.testtype.DeviceJUnit4ClassRunner
+import com.android.tradefed.testtype.junit4.BaseHostJUnit4Test
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(DeviceJUnit4ClassRunner::class)
+class CheckFlaggedApisTest : BaseHostJUnit4Test() {
+  @Test fun testPlaceholder() {}
+}