fix: report energy usage in nanojoules

CHANGELOG.md

@@ -7,6 +7,10 @@
 - Distributed tracing without performance (#3196)
 - Report database backing store information for Core Data (#3231)
 
+### Fixes
+
+- Report correct units (nanojoules) for profiling energy metrics (#3262)
+
 ## 8.10.0
 
 ### Features

Sources/Sentry/SentryMetricProfiler.mm

@@ -32,6 +32,7 @@ @implementation SentryMetricReading
 
 NSString *const kSentryMetricProfilerSerializationUnitBytes = @"byte";
 NSString *const kSentryMetricProfilerSerializationUnitPercentage = @"percent";
+NSString *const kSentryMetricProfilerSerializationUnitNanoJoules = @"nanojoule";
 
 // Currently set to 10 Hz as we don't anticipate much utility out of a higher resolution when
 // sampling CPU usage and memory footprint, and we want to minimize the overhead of making the
@@ -133,7 +134,7 @@ - (void)stop
     if (cpuEnergyUsage.count > 0) {
         dict[kSentryMetricProfilerSerializationKeyCPUEnergyUsage]
             = serializeValuesWithNormalizedTime(cpuEnergyUsage,
-                kSentryMetricProfilerSerializationUnitBytes, startSystemTime, endSystemTime);
+                kSentryMetricProfilerSerializationUnitNanoJoules, startSystemTime, endSystemTime);
     }
 
     if (cpuUsage.count > 0) {

Sources/Sentry/include/SentryMetricProfiler.h

@@ -14,6 +14,7 @@ SENTRY_EXTERN NSString *const kSentryMetricProfilerSerializationKeyCPUEnergyUsag
 
 SENTRY_EXTERN NSString *const kSentryMetricProfilerSerializationUnitBytes;
 SENTRY_EXTERN NSString *const kSentryMetricProfilerSerializationUnitPercentage;
+SENTRY_EXTERN NSString *const kSentryMetricProfilerSerializationUnitNanoJoules;
 
 // The next two types are technically the same as far as the type system is concerned, but they
 // actually contain different mixes of value types, so define them separately. If they ever change,

Tests/SentryProfilerTests/SentryProfilerSwiftTests.swift

@@ -603,12 +603,12 @@ private extension SentryProfilerSwiftTests {
 
         let expectedUsageReadings = fixture.mockUsageReadingsPerBatch * metricsBatches
 
-        try assertMetricValue(measurements: measurements, key: kSentryMetricProfilerSerializationKeyCPUUsage, numberOfReadings: expectedUsageReadings, expectedValue: fixture.mockCPUUsage, transaction: transaction)
+        try assertMetricValue(measurements: measurements, key: kSentryMetricProfilerSerializationKeyCPUUsage, numberOfReadings: expectedUsageReadings, expectedValue: fixture.mockCPUUsage, transaction: transaction, expectedUnits: kSentryMetricProfilerSerializationUnitPercentage)
 
-        try assertMetricValue(measurements: measurements, key: kSentryMetricProfilerSerializationKeyMemoryFootprint, numberOfReadings: expectedUsageReadings, expectedValue: fixture.mockMemoryFootprint, transaction: transaction)
+        try assertMetricValue(measurements: measurements, key: kSentryMetricProfilerSerializationKeyMemoryFootprint, numberOfReadings: expectedUsageReadings, expectedValue: fixture.mockMemoryFootprint, transaction: transaction, expectedUnits: kSentryMetricProfilerSerializationUnitBytes)
 
         // we wind up with one less energy reading. since we must use the difference between readings to get actual values, the first one is only the baseline reading.
-        try assertMetricValue(measurements: measurements, key: kSentryMetricProfilerSerializationKeyCPUEnergyUsage, numberOfReadings: expectedUsageReadings - 1, expectedValue: fixture.mockEnergyUsage, transaction: transaction)
+        try assertMetricValue(measurements: measurements, key: kSentryMetricProfilerSerializationKeyCPUEnergyUsage, numberOfReadings: expectedUsageReadings - 1, expectedValue: fixture.mockEnergyUsage, transaction: transaction, expectedUnits: kSentryMetricProfilerSerializationUnitNanoJoules)
 
 #if !os(macOS)
         try assertMetricEntries(measurements: measurements, key: kSentryProfilerSerializationKeySlowFrameRenders, expectedEntries: fixture.expectedSlowFrames, transaction: transaction)
@@ -655,7 +655,7 @@ private extension SentryProfilerSwiftTests {
         }
     }
 
-    func assertMetricValue<T: Equatable>(measurements: [String: Any], key: String, numberOfReadings: Int, expectedValue: T? = nil, transaction: Transaction) throws {
+    func assertMetricValue<T: Equatable>(measurements: [String: Any], key: String, numberOfReadings: Int, expectedValue: T? = nil, transaction: Transaction, expectedUnits: String) throws {
         let metricContainer = try XCTUnwrap(measurements[key] as? [String: Any])
         let values = try XCTUnwrap(metricContainer["values"] as? [[String: Any]])
         XCTAssertEqual(values.count, numberOfReadings, "Wrong number of values under \(key)")
@@ -666,6 +666,9 @@ private extension SentryProfilerSwiftTests {
 
             let timestamp = try XCTUnwrap(values[0]["elapsed_since_start_ns"] as? NSString)
             try assertTimestampOccursWithinTransaction(timestamp: timestamp, transaction: transaction)
+
+            let actualUnits = try XCTUnwrap(metricContainer["unit"] as? String)
+            XCTAssertEqual(actualUnits, expectedUnits)
         }
     }