Set negative battery levels to null in mobile context (close #698)

Author: mscwilson

snowplow-tracker/src/androidTest/java/com/snowplowanalytics/snowplow/internal/tracker/MockDeviceInfoMonitor.kt

@@ -20,6 +20,8 @@ import com.snowplowanalytics.core.utils.DeviceInfoMonitor
 class MockDeviceInfoMonitor : DeviceInfoMonitor() {
     private val methodAccessCounts: MutableMap<String, Int> = HashMap()
     var customIdfa: String? = "XJKLJSALFKJ"
+    var batteryLevel: Int = 20
+    
     override val osType: String
         get() {
             increaseMethodAccessCount("getOsType")
@@ -73,7 +75,7 @@ class MockDeviceInfoMonitor : DeviceInfoMonitor() {
 
     override fun getBatteryStateAndLevel(context: Context): Pair<String?, Int>? {
         increaseMethodAccessCount("getBatteryStateAndLevel")
-        return Pair("charging", 20)
+        return Pair("charging", batteryLevel)
     }
 
     override val availableStorage: Long

snowplow-tracker/src/androidTest/java/com/snowplowanalytics/snowplow/internal/tracker/PlatformContextTest.kt

@@ -341,6 +341,20 @@ class PlatformContextTest {
         Assert.assertEquals("r13", sdjData[Parameters.APP_SET_ID_SCOPE])
     }
 
+    @Test
+    fun batteryLevelNotTrackedIfNegative() {
+        val deviceInfoMonitor = MockDeviceInfoMonitor()
+        deviceInfoMonitor.batteryLevel = -1
+        val platformContext = PlatformContext(0, 0, deviceInfoMonitor, context = context)
+
+        val sdj = platformContext.getMobileContext(false)
+        Assert.assertNotNull(sdj)
+        val sdjData = sdj!!.map["data"] as Map<*, *>
+
+        Assert.assertEquals("charging", sdjData[Parameters.BATTERY_STATE])
+        Assert.assertFalse(sdjData.containsKey(Parameters.BATTERY_LEVEL))
+    }
+
     // --- PRIVATE
     private val context: Context
         get() = InstrumentationRegistry.getInstrumentation().targetContext

snowplow-tracker/src/main/java/com/snowplowanalytics/core/tracker/PlatformContext.kt

@@ -13,6 +13,7 @@
 package com.snowplowanalytics.core.tracker
 
 import android.content.Context
+import android.util.Pair
 import com.snowplowanalytics.core.constants.Parameters
 import com.snowplowanalytics.core.constants.TrackerConstants
 import com.snowplowanalytics.core.utils.DeviceInfoMonitor
@@ -147,7 +148,11 @@ class PlatformContext(
         if (trackBatState || trackBatLevel) {
             val batteryInfo = deviceInfoMonitor.getBatteryStateAndLevel(context)
             if (trackBatState) { addToMap(Parameters.BATTERY_STATE, fromRetrieverOr(retriever.batteryState) { batteryInfo?.first }, pairs) }
-            if (trackBatLevel) { addToMap(Parameters.BATTERY_LEVEL, fromRetrieverOr(retriever.batteryLevel) { batteryInfo?.second }, pairs) }
+            if (trackBatLevel) {
+                val batteryLevel = fromRetrieverOr(retriever.batteryLevel) { batteryInfo?.second }
+                val validBatteryLevel = if (batteryLevel != null && batteryLevel >= 0) batteryLevel else null
+                addToMap(Parameters.BATTERY_LEVEL, validBatteryLevel, pairs)
+            }
         }
         // Memory
         if (shouldTrack(PlatformContextProperty.SYSTEM_AVAILABLE_MEMORY)) {