Reactive fix helpers and extensions tests

lib/extensions.dart

@@ -19,14 +19,18 @@ extension Concept2DateExtension on DateTime {
   }
 
   Uint8List toBytes() {
-    List<int> bytes = [];
+    int yearOffset = year - 2000;
 
-    // int yearoffset = (year - 2000);
-    // bytes.add( (day & 0x0F)<<4 | month & 0x0F);
+    int dateValue = (yearOffset << 9) | (day << 4) | month;
 
-    // int day_year_byte = (day & 0x1F) | ;
+    Uint8List dateBytes =
+        dateValue.toBytes(fillBytes: 2, endian: Endian.little);
 
-    return Uint8List.fromList(bytes);
+    return Uint8List.fromList([
+      ...dateBytes,
+      minute,
+      hour,
+    ]);
   }
 }
 

lib/helpers.dart

@@ -10,14 +10,17 @@ import 'models/workout.dart';
 /// Concept2's structure is date LO, Date HI, Time LO, Time HI
 /// see also https://www.c2forum.com/viewtopic.php?f=15&t=200769
 DateTime timeFromBytes(Uint8List bytes) {
-  int date = CsafeIntExtension.fromBytes(bytes.sublist(0, 2));
+  int date =
+      CsafeIntExtension.fromBytes(bytes.sublist(0, 2), endian: Endian.little);
 
   int month = date & 0x0F;
   int day = (date >> 4) & 0x1F;
   int year = (date >> 9) & 0x7f;
 
-  int minutes = CsafeIntExtension.fromBytes(bytes.sublist(2, 3));
-  int hours = CsafeIntExtension.fromBytes(bytes.sublist(3, 4));
+  int minutes =
+      CsafeIntExtension.fromBytes(bytes.sublist(2, 3), endian: Endian.little);
+  int hours =
+      CsafeIntExtension.fromBytes(bytes.sublist(3, 4), endian: Endian.little);
 
   return DateTime(year + 2000, month, day, hours, minutes);
 }
@@ -44,17 +47,34 @@ WorkoutGoal? guessReasonableSplit(WorkoutGoal goal) {
 
 //https://stackoverflow.com/questions/54852585/how-to-convert-a-duration-like-string-to-a-real-duration-in-flutter
 Duration parseDuration(String s) {
+  final parts = s.split(':');
+  if (parts.length < 2 || parts.length > 3) {
+    throw const FormatException('Invalid duration format');
+  }
+
+  final secString = parts.last;
+  final sec = double.tryParse(secString);
+  if (sec == null) {
+    throw const FormatException('Invalid seconds value');
+  }
+
+  final minString = parts[parts.length - 2];
+  final minutes = int.tryParse(minString);
+  if (minutes == null) {
+    throw const FormatException('Invalid minutes value');
+  }
+
   int hours = 0;
-  int minutes = 0;
-  int micros;
-  List<String> parts = s.split(':');
-  if (parts.length > 2) {
-    hours = int.parse(parts[parts.length - 3]);
+  if (parts.length == 3) {
+    hours = int.tryParse(parts.first) ??
+        (throw const FormatException('Invalid hours value'));
   }
-  if (parts.length > 1) {
-    minutes = int.parse(parts[parts.length - 2]);
+
+  if (hours < 0 || minutes < 0 || sec < 0) {
+    throw RangeError('Duration values must be non-negative');
   }
-  micros = (double.parse(parts[parts.length - 1]) * 1000000).toInt();
+
+  final micros = (sec * Duration.microsecondsPerSecond).round();
   return Duration(hours: hours, minutes: minutes, microseconds: micros);
 }
 
@@ -73,6 +93,9 @@ String durationToSplit(Duration d) {
 // source: https://www.concept2.com/indoor-rowers/training/calculators/watts-calculator
 
 double splitToWatts(Duration split) {
+  if (split.inMilliseconds <= 0) {
+    throw RangeError('split must be positive');
+  }
   double secondsperMeter =
       split.inMilliseconds / Duration.millisecondsPerSecond;
   var rawWatts = (2.8 / pow(secondsperMeter / 500, 3));
@@ -82,6 +105,9 @@ double splitToWatts(Duration split) {
 // pace = ³√(2.80/watts); pace = seconds per meter
 // source: https://www.concept2.com/indoor-rowers/training/calculators/watts-calculator
 String wattsToSplit(double watts) {
+  if (watts < 0) {
+    throw RangeError('watts must be non-negative');
+  }
   if (watts == 0) {
     return "0:00.0";
   }

test/extensions_test.dart

@@ -7,16 +7,16 @@ void main() {
   group("Concept2DateExtension - ", () {
     test('converting a time from bytes', () {
       final bytes = Uint8List.fromList([156, 42, 1, 14]); //date 10908
-      expect(
-          Concept2DateExtension.fromBytes(bytes), DateTime(2021, 12, 9, 14, 1));
-      // expect(CsafeIntExtension.fromBytes(bytes, Endian.little), 2147483648);
+      final date = Concept2DateExtension.fromBytes(bytes);
+      expect(date, DateTime(2021, 12, 9, 14, 1));
+      expect(date.toBytes(), bytes);
     });
 
     test('converting another time from bytes', () {
       final bytes = Uint8List.fromList([241, 45, 1, 14]);
-      expect(
-          Concept2DateExtension.fromBytes(bytes), DateTime(2022, 1, 31, 14, 1));
-      // expect(CsafeIntExtension.fromBytes(bytes, Endian.little), 2147483648);
+      final date = Concept2DateExtension.fromBytes(bytes);
+      expect(date, DateTime(2022, 1, 31, 14, 1));
+      expect(date.toBytes(), bytes);
     });
 
     test('converting a date from a verifiable source from bytes', () {
@@ -25,26 +25,27 @@ void main() {
       // 00011101 10010100  00010000 00001001
       // final bytes = Uint8List.fromList([29, 148, 16, 9]);
       final bytes = Uint8List.fromList([148, 29, 9, 16]);
-
-      expect(Concept2DateExtension.fromBytes(bytes),
-          DateTime(2014, 4, 25, 16, 09));
+      final date = Concept2DateExtension.fromBytes(bytes);
+      expect(date, DateTime(2014, 4, 25, 16, 09));
       // 25th April 2014 @ 16:09 (4:09pm)
+      expect(date.toBytes(), bytes);
     });
 
     test('converting a date in 2022 from bytes', () {
       final bytes = Uint8List.fromList([133, 44, 14, 14]);
-      expect(
-          Concept2DateExtension.fromBytes(bytes), DateTime(2022, 5, 8, 14, 14));
+      final date = Concept2DateExtension.fromBytes(bytes);
+      expect(date, DateTime(2022, 5, 8, 14, 14));
+      expect(date.toBytes(), bytes);
     });
   });
 
   group("Concept2DurationExtension - ", () {
-    // TODO: need bytes to use as test case
-    // test('converting a duration from bytes', () {
-    //   // TODO: fixme, my endianness is backwards
-    //   final bytes = Uint8List.fromList([42, 156, 1, 14]); //date 10908
-    //   expect(
-    //       Concept2DurationExtension.fromBytes(bytes), DateTime(2021, 12, 9, 14, 1));
-    // });
+    test('converts a duration from bytes and back again', () {
+      // 1 minute, 30.5 seconds -> 90500 ms -> 9050 hundred of a second
+      final bytes = Uint8List.fromList([90, 35, 0]);
+      final duration = Concept2DurationExtension.fromBytes(bytes);
+      expect(duration, Duration(minutes: 1, seconds: 30, milliseconds: 500));
+      expect(duration.toBytes(), bytes);
+    });
   });
 }

test/helpers_test.dart

@@ -1,10 +1,10 @@
+import 'dart:typed_data';
+
 import 'package:c2bluetooth/helpers.dart';
 import 'package:c2bluetooth/models/workout.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 void main() {
-
-
   group("guessReasonableSplit - ", () {
     test("test with reasonable distance", () {
       expect(guessReasonableSplit(WorkoutGoal.meters(2000)),
@@ -35,10 +35,13 @@ void main() {
     test('3:00.2', () {
       expect(parseDuration("3:00.2"), Duration(minutes: 3, milliseconds: 200));
     });
-    // TODO: Update errors for splitToWatts()
-    // test('When invalid split format, should throw error', () {
-    //   expect(() => splitToWatts('0'), throwsFormatException);
-    // });
+    test('throws FormatException on malformed string', () {
+      expect(() => parseDuration('foo'), throwsFormatException);
+    });
+
+    test('throws RangeError on negative values', () {
+      expect(() => parseDuration('-1:00.0'), throwsRangeError);
+    });
   });
 
   group('splitToWatts -', () {
@@ -59,10 +62,12 @@ void main() {
       var result = splitToWatts(Duration(minutes: 3));
       expect(result, 60);
     });
-    // TODO: Update errors for splitToWatts()
-    // test('When invalid split format, should throw error', () {
-    //   expect(() => splitToWatts('0'), throwsFormatException);
-    // });
+    test('throws RangeError when split is non-positive', () {
+      expect(() => splitToWatts(Duration.zero), throwsRangeError);
+    });
+    test('throws RangeError when split is negative', () {
+      expect(() => splitToWatts(Duration(seconds: -5)), throwsRangeError);
+    });
   });
   group('wattsToSplit -', () {
     test('When watts is 179, should be 2:05.0', () {
@@ -85,5 +90,34 @@ void main() {
       var result = wattsToSplit(55555);
       expect(result, '0:18.5');
     });
+    test('throws RangeError when watts is negative', () {
+      expect(() => wattsToSplit(-10), throwsRangeError);
+    });
+  });
+  group('timeFromBytes -', () {
+    test('should convert PM date bytes to DateTime', () {
+      final bytes = Uint8List.fromList([156, 42, 1, 14]);
+      expect(timeFromBytes(bytes), DateTime(2021, 12, 9, 14, 1));
+    });
+
+    test('should convert another valid byte sequence', () {
+      final bytes = Uint8List.fromList([241, 45, 1, 14]);
+      expect(timeFromBytes(bytes), DateTime(2022, 1, 31, 14, 1));
+    });
+  });
+
+  group('durationToSplit -', () {
+    test('converts a 2:05 duration', () {
+      expect(durationToSplit(Duration(minutes: 2, seconds: 5)), '2:05.0');
+    });
+
+    test('handles seconds only', () {
+      expect(durationToSplit(Duration(seconds: 30)), '0:30.0');
+    });
+
+    test('handles fractional seconds', () {
+      expect(
+          durationToSplit(Duration(minutes: 1, milliseconds: 900)), '1:00.9');
+    });
   });
 }