feat: Take sampleRate from metadata

sentry-android-core/src/main/java/io/sentry/android/core/ManifestMetadataReader.java

@@ -14,6 +14,7 @@ final class ManifestMetadataReader {
   static final String DSN_KEY = "io.sentry.dsn";
   static final String DEBUG_KEY = "io.sentry.debug";
   static final String DEBUG_LEVEL = "io.sentry.debug.level";
+  static final String SAMPLE_RATE = "io.sentry.sample-rate";
   static final String ANR_ENABLE = "io.sentry.anr.enable";
   static final String ANR_REPORT_DEBUG = "io.sentry.anr.report-debug";
   static final String ANR_TIMEOUT_INTERVAL_MILLS = "io.sentry.anr.timeout-interval-mills";
@@ -22,8 +23,9 @@ final class ManifestMetadataReader {
 
   private ManifestMetadataReader() {}
 
-  static void applyMetadata(Context context, SentryAndroidOptions options) {
+  static void applyMetadata(@NotNull Context context, @NotNull SentryAndroidOptions options) {
     if (context == null) throw new IllegalArgumentException("The application context is required.");
+    if (options == null) throw new IllegalArgumentException("The options object is required.");
 
     try {
       Bundle metadata = getMetadata(context);
@@ -44,6 +46,14 @@ static void applyMetadata(Context context, SentryAndroidOptions options) {
         options.getLogger().log(SentryLevel.DEBUG, "isAnrEnabled read: %s", isAnrEnabled);
         options.setAnrEnabled(isAnrEnabled);
 
+        if (options.getSampleRate() == null) {
+          Double sampleRate = metadata.getDouble(SAMPLE_RATE, -1);
+          options.getLogger().log(SentryLevel.DEBUG, "sampleRate read: %s", sampleRate);
+          if (sampleRate != -1) {
+            options.setSampleRate(sampleRate);
+          }
+        }
+
         boolean isAnrReportInDebug =
             metadata.getBoolean(ANR_REPORT_DEBUG, options.isAnrReportInDebug());
         options

sentry-android-core/src/test/java/io/sentry/android/core/ManifestMetadataReaderTest.kt

@@ -1,17 +1,25 @@
 package io.sentry.android.core
 
 import android.content.Context
+import android.content.pm.ApplicationInfo
+import android.content.pm.PackageManager
+import android.os.Bundle
 import androidx.test.core.app.ApplicationProvider
 import androidx.test.ext.junit.runners.AndroidJUnit4
 import com.nhaarman.mockitokotlin2.any
+import com.nhaarman.mockitokotlin2.anyVararg
+import com.nhaarman.mockitokotlin2.argWhere
 import com.nhaarman.mockitokotlin2.eq
 import com.nhaarman.mockitokotlin2.mock
 import com.nhaarman.mockitokotlin2.never
 import com.nhaarman.mockitokotlin2.verify
+import com.nhaarman.mockitokotlin2.whenever
 import io.sentry.core.ILogger
 import io.sentry.core.SentryLevel
 import kotlin.test.BeforeTest
 import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNull
 import kotlin.test.assertTrue
 import org.junit.runner.RunWith
 
@@ -43,4 +51,72 @@ class ManifestMetadataReaderTest {
         options.setLogger(logger)
         verify(logger, never()).log(eq(SentryLevel.ERROR), any<String>(), any())
     }
+
+    @Test
+    fun `applyMetadata reads sampleRate from metadata`() {
+        // Arrange
+        val options = SentryAndroidOptions()
+        val expectedPackageName = "io.sentry.test"
+        val expectedSampleRate = 0.99
+        val contextMock: Context = mock()
+        whenever(contextMock.packageName).thenReturn(expectedPackageName)
+        val bundle: Bundle = mock()
+        whenever(bundle.getDouble(eq(ManifestMetadataReader.SAMPLE_RATE), anyVararg())).thenReturn(expectedSampleRate)
+        val packageManagerMock: PackageManager = mock()
+        val applicationInfo: ApplicationInfo = mock()
+        applicationInfo.metaData = bundle
+        whenever(packageManagerMock.getApplicationInfo(argWhere { it == expectedPackageName }, eq(PackageManager.GET_META_DATA))).thenReturn(applicationInfo)
+        whenever(contextMock.packageManager).thenReturn(packageManagerMock)
+
+        // Act
+        ManifestMetadataReader.applyMetadata(contextMock, options)
+
+        // Assert
+        assertEquals(expectedSampleRate, options.sampleRate)
+    }
+
+    @Test
+    fun `applyMetadata does not override sampleRate from options`() {
+        // Arrange
+        val expectedSampleRate = 0.99
+        val options = SentryAndroidOptions()
+        options.sampleRate = expectedSampleRate
+        val expectedPackageName = "io.sentry.test"
+        val contextMock: Context = mock()
+        whenever(contextMock.packageName).thenReturn(expectedPackageName)
+        val bundle: Bundle = mock()
+        whenever(bundle.getDouble(eq(ManifestMetadataReader.SAMPLE_RATE), anyVararg())).thenReturn(0.1)
+        val packageManagerMock: PackageManager = mock()
+        val applicationInfo: ApplicationInfo = mock()
+        applicationInfo.metaData = bundle
+        whenever(packageManagerMock.getApplicationInfo(argWhere { it == expectedPackageName }, eq(PackageManager.GET_META_DATA))).thenReturn(applicationInfo)
+        whenever(contextMock.packageManager).thenReturn(packageManagerMock)
+
+        // Act
+        ManifestMetadataReader.applyMetadata(contextMock, options)
+
+        // Assert
+        assertEquals(expectedSampleRate, options.sampleRate)
+    }
+
+    @Test
+    fun `applyMetadata without specifying sampleRate, stays null`() {
+        // Arrange
+        val options = SentryAndroidOptions()
+        val expectedPackageName = "io.sentry.test"
+        val contextMock: Context = mock()
+        whenever(contextMock.packageName).thenReturn(expectedPackageName)
+        val bundle: Bundle = mock()
+        val packageManagerMock: PackageManager = mock()
+        val applicationInfo: ApplicationInfo = mock()
+        applicationInfo.metaData = bundle
+        whenever(packageManagerMock.getApplicationInfo(argWhere { it == expectedPackageName }, eq(PackageManager.GET_META_DATA))).thenReturn(applicationInfo)
+        whenever(contextMock.packageManager).thenReturn(packageManagerMock)
+
+        // Act
+        ManifestMetadataReader.applyMetadata(contextMock, options)
+
+        // Assert
+        assertNull(options.sampleRate)
+    }
 }