For #14735: Remove debug logs from release build. (#15747)

app/proguard-rules.pro

@@ -45,6 +45,14 @@
     boolean ANDROID_DETECTED return true;
 }
 
+####################################################################################################
+# Remove debug logs from release builds
+####################################################################################################
+-assumenosideeffects class android.util.Log {
+    public static boolean isLoggable(java.lang.String, int);
+    public static int d(...);
+}
+
 ####################################################################################################
 # Mozilla Application Services
 ####################################################################################################

app/src/main/java/org/mozilla/fenix/FenixApplication.kt

@@ -32,7 +32,6 @@ import mozilla.components.service.glean.config.Configuration
 import mozilla.components.service.glean.net.ConceptFetchHttpUploader
 import mozilla.components.support.base.log.Log
 import mozilla.components.support.base.log.logger.Logger
-import mozilla.components.support.base.log.sink.AndroidLogSink
 import mozilla.components.support.ktx.android.content.isMainProcess
 import mozilla.components.support.ktx.android.content.runOnlyInMainProcess
 import mozilla.components.support.locale.LocaleAwareApplication
@@ -42,7 +41,6 @@ import mozilla.components.support.utils.logElapsedTime
 import mozilla.components.support.webextensions.WebExtensionSupport
 import org.mozilla.fenix.components.Components
 import org.mozilla.fenix.components.metrics.MetricServiceType
-import org.mozilla.fenix.ext.components
 import org.mozilla.fenix.ext.settings
 import org.mozilla.fenix.perf.StorageStatsMetrics
 import org.mozilla.fenix.perf.StartupTimeline
@@ -114,7 +112,7 @@ open class FenixApplication : LocaleAwareApplication(), Provider {
         setupCrashReporting()
 
         // We want the log messages of all builds to go to Android logcat
-        Log.addSink(AndroidLogSink())
+        Log.addSink(FenixLogSink(logsDebug = Config.channel.isDebug))
     }
 
     @CallSuper

app/src/main/java/org/mozilla/fenix/FenixLogSink.kt

@@ -0,0 +1,30 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix
+
+import mozilla.components.support.base.log.Log
+import mozilla.components.support.base.log.sink.AndroidLogSink
+import mozilla.components.support.base.log.sink.LogSink
+
+/**
+ * Fenix [LogSink] implementation that writes to Android's log, depending on settings.
+ *
+ * @param logsDebug If set to false, removes logging of debug logs.
+ */
+class FenixLogSink(private val logsDebug: Boolean = true) : LogSink {
+
+    private val androidLogSink = AndroidLogSink()
+
+    override fun log(
+        priority: Log.Priority,
+        tag: String?,
+        throwable: Throwable?,
+        message: String?
+    ) {
+        if (priority == Log.Priority.DEBUG && !logsDebug)
+            return
+        androidLogSink.log(priority, tag, throwable, message)
+    }
+}

app/src/test/java/org/mozilla/fenix/FenixLogSinkTest.kt

@@ -0,0 +1,77 @@
+package org.mozilla.fenix
+
+import android.util.Log
+import io.mockk.mockkStatic
+import io.mockk.unmockkStatic
+import io.mockk.verify
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+
+class FenixLogSinkTest {
+
+    @Before
+    fun setup() {
+        mockkStatic(Log::class)
+    }
+
+    @After
+    fun teardown() {
+        unmockkStatic(Log::class)
+    }
+
+    @Test
+    fun `GIVEN we're in a release build WHEN we log debug statements THEN logs should not be forwarded`() {
+        val logSink = FenixLogSink(false)
+        logSink.log(
+            mozilla.components.support.base.log.Log.Priority.DEBUG,
+            "test",
+            message = "test"
+        )
+        verify(exactly = 0) { Log.println(Log.DEBUG, "test", "test") }
+    }
+
+    @Test
+    fun `GIVEN we're in a release build WHEN we log error statements THEN logs should be forwarded`() {
+        val logSink = FenixLogSink(false)
+        logSink.log(
+            mozilla.components.support.base.log.Log.Priority.ERROR,
+            "test",
+            message = "test"
+        )
+        verify(exactly = 1) { Log.println(Log.ERROR, "test", "test") }
+    }
+
+    @Test
+    fun `GIVEN we're in a release build WHEN we log warn statements THEN logs should be forwarded`() {
+        val logSink = FenixLogSink(false)
+        logSink.log(
+            mozilla.components.support.base.log.Log.Priority.WARN,
+            "test",
+            message = "test"
+        )
+        verify(exactly = 1) { Log.println(Log.WARN, "test", "test") }
+    }
+
+    @Test
+    fun `GIVEN we're in a release build WHEN we log info statements THEN logs should be forwarded`() {
+        val logSink = FenixLogSink(false)
+        logSink.log(
+            mozilla.components.support.base.log.Log.Priority.INFO,
+            "test",
+            message = "test"
+        )
+        verify(exactly = 1) { Log.println(Log.INFO, "test", "test") }
+    }
+
+    @Test
+    fun `GIVEN we're in a debug build WHEN we log debug statements THEN logs should be forwarded`() {
+        val logSink = FenixLogSink(true)
+        logSink.log(
+            mozilla.components.support.base.log.Log.Priority.DEBUG,
+            "test",
+            message = "test"
+        )
+        verify(exactly = 1) { Log.println(Log.DEBUG, "test", "test") }
+    }
+}