1 files changed, 60 insertions, 0 deletions
diff --git a/build-system/gradle-settings-api/src/metalavaTest/java/com/android/build/api/metalava/StableApiTest.kt b/build-system/gradle-settings-api/src/metalavaTest/java/com/android/build/api/metalava/StableApiTest.kt
new file mode 100644
index 0000000000..b55c263e2b
--- /dev/null
+++ b/build-system/gradle-settings-api/src/metalavaTest/java/com/android/build/api/metalava/StableApiTest.kt
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2023 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.build.api.metalava
+
+import com.android.testutils.TestUtils
+import com.google.common.io.Resources
+import org.junit.Test
+import java.lang.AssertionError
+import java.nio.charset.StandardCharsets
+import java.nio.file.Files
+import java.nio.file.Path
+import java.nio.file.Paths
+
+/**
+ * Test that tries to ensure that our public API remains stable.
+ */
+class StableApiTest {
+    @Test
+    fun checkCurrentApi() {
+        @Suppress("UnstableApiUsage")
+        val expected: List<String> = Resources.asCharSource(EXPECTED_FILE, StandardCharsets.UTF_8).readLines()
+        val actual = Files.readAllLines(CURRENT, StandardCharsets.UTF_8)
+        if (expected != actual) {
+            throw AssertionError(
+                """
+                    The Android Gradle Plugin API does not match the expectation file.
+
+                    Either:
+                      * revert the api change
+                      * or apply the below changes by running the updateApi task:
+                            gradle :base:build-system:gradle-settings-api:updateMetalavaApi
+
+                    To update all the API expectation files, run
+                        gradlew updateApi
+                    """.trimIndent() +
+                        TestUtils.getDiff(expected.toTypedArray(), actual.toTypedArray())
+            )
+        }
+    }
+
+    companion object {
+        @Suppress("UnstableApiUsage")
+        private val EXPECTED_FILE = Resources.getResource("current.txt")
+        val CURRENT: Path = Paths.get(System.getProperty("metalavaCurrentApiFile")!!).resolve("current.txt")
+    }
+}