From 77f29fc343c96c42f1a3ea22a70c2b5d9572203c Mon Sep 17 00:00:00 2001
From: Yuyang Huang <yuyanghuang@google.com>
Date: Thu, 26 Dec 2024 15:35:08 +0900
Subject: [PATCH] Log and report terrible errors for improved debugging and
 tracking

When a terrible error occurs, this change ensures that it is both logged
using Log.wtf() and reported via a dedicated metric. This dual approach
provides comprehensive error information for debugging in dogfood
environments (Log.wtf()) and tracks the occurrence of these errors in
production (via metrics).

Test: TH
Change-Id: Ic376f3789ab0cc9b094e79301849492143ed777c
---
 .../net/module/util/TerribleErrorLog.java     | 41 +++++++++++++++
 .../net/module/util/TerribleErrorLogTest.kt   | 50 +++++++++++++++++++
 2 files changed, 91 insertions(+)
 create mode 100644 staticlibs/framework/com/android/net/module/util/TerribleErrorLog.java
 create mode 100644 staticlibs/tests/unit/src/com/android/net/module/util/TerribleErrorLogTest.kt

diff --git a/staticlibs/framework/com/android/net/module/util/TerribleErrorLog.java b/staticlibs/framework/com/android/net/module/util/TerribleErrorLog.java
new file mode 100644
index 0000000000..b4f7642b62
--- /dev/null
+++ b/staticlibs/framework/com/android/net/module/util/TerribleErrorLog.java
@@ -0,0 +1,41 @@
+/*
+ * 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.net.module.util;
+
+import android.annotation.NonNull;
+import android.util.Log;
+
+import java.util.function.BiConsumer;
+
+/**
+ * Utility class for logging terrible errors and reporting them for tracking.
+ *
+ * @hide
+ */
+public class TerribleErrorLog {
+
+    private static final String TAG = TerribleErrorLog.class.getSimpleName();
+
+    /**
+     * Logs a terrible error and reports metrics through a provided statsLog.
+     */
+    public static void logTerribleError(@NonNull BiConsumer<Integer, Integer> statsLog,
+            @NonNull String message, int protoType, int errorType) {
+        statsLog.accept(protoType, errorType);
+        Log.wtf(TAG, message);
+    }
+}
diff --git a/staticlibs/tests/unit/src/com/android/net/module/util/TerribleErrorLogTest.kt b/staticlibs/tests/unit/src/com/android/net/module/util/TerribleErrorLogTest.kt
new file mode 100644
index 0000000000..5fd634e210
--- /dev/null
+++ b/staticlibs/tests/unit/src/com/android/net/module/util/TerribleErrorLogTest.kt
@@ -0,0 +1,50 @@
+/*
+ * 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.net.module.util
+
+import android.util.Log
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import androidx.test.filters.SmallTest
+import com.android.testutils.tryTest
+import kotlin.test.assertContentEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+@SmallTest
+class TerribleErrorLogTest {
+    @Test
+    fun testLogTerribleError() {
+        val wtfCaptures = mutableListOf<String>()
+        val prevHandler = Log.setWtfHandler { tag, what, system ->
+            wtfCaptures.add("$tag,${what.message}")
+        }
+        val statsLogCapture = mutableListOf<Pair<Int, Int>>()
+        val testStatsLog = object {
+            fun write(protoType: Int, errorType: Int) {
+                statsLogCapture.add(protoType to errorType)
+            }
+        }
+        tryTest {
+            TerribleErrorLog.logTerribleError(testStatsLog::write, "error", 1, 2)
+            assertContentEquals(listOf(1 to 2), statsLogCapture)
+            assertContentEquals(listOf("TerribleErrorLog,error"), wtfCaptures)
+        } cleanup {
+            Log.setWtfHandler(prevHandler)
+        }
+    }
+}