Dart null safety - minor review changes

dart/lib/flat_buffers.dart

@@ -30,12 +30,14 @@ class BufferContext {
 
   ByteData get buffer => _buffer;
 
+  /// Create from a FlatBuffer represented by a list of bytes (uint8).
   factory BufferContext.fromBytes(List<int> byteList) {
     Uint8List uint8List = _asUint8List(byteList);
     ByteData buf = new ByteData.view(uint8List.buffer, uint8List.offsetInBytes);
     return BufferContext(buf);
   }
 
+  /// Create from a FlatBuffer represented by ByteData.
   BufferContext(this._buffer);
 
   int derefObject(int offset) {
@@ -112,7 +114,6 @@ class Builder {
   final int initialSize;
 
   /// The list of existing VTable(s).
-  //final List<_VTable> _vTables = <_VTable>[];
   final List<int> _vTables = List<int>.filled(16, 0, growable: true)
     ..length = 0;
 
@@ -128,7 +129,7 @@ class Builder {
   int _tail = 0;
 
   /// The location of the end of the current table, measured in bytes from the
-  /// end of [_buf], or `null` if a table is not currently being built.
+  /// end of [_buf].
   int _currentTableEndTail = 0;
 
   _VTable? _currentVTable;

dart/lib/src/builder.dart

@@ -256,7 +256,7 @@ class Builder {
     bd.buffer.asUint8List().setAll(0, buffer);
     return bd.buffer;
   }
-  
+
   void _integrityCheckOnValueAddition() {
     if (_finished) {
       throw StateError('Adding values after finish is prohibited');
@@ -288,7 +288,7 @@ class Builder {
     _writeUInt(byteWidth, 1);
     _finished = true;
   }
-  
+
   _StackValue _createVector(int start, int vecLength, int step, [_StackValue? keys]) {
     var bitWidth = BitWidthUtil.uwidth(vecLength);
     var prefixElements = 1;
@@ -383,7 +383,7 @@ class Builder {
     }
     _endMap(pointer);
   }
-  
+
   void _endMap(_StackPointer pointer) {
     final vecLength = (_stack.length - pointer.stackPosition) >> 1;
     final offsets = <int>[];
@@ -552,10 +552,10 @@ class _StackValue {
 
   BitWidth elementWidth(int size, int index) {
     if (ValueTypeUtils.isInline(_type)) return _width;
+    final offset = offsetLoc - _offset!;
     for(var i = 0; i < 4; i++) {
       final width = 1 << i;
       final offsetLoc = size + BitWidthUtil.paddingSize(size, width) + index * width;
-      final offset = offsetLoc - _offset!;
       final bitWidth = BitWidthUtil.uwidth(offset);
       if (1 << bitWidth.index == width) {
         return bitWidth;

dart/pubspec.yaml

@@ -17,4 +17,4 @@ dev_dependencies:
   test_reflective_loader: ^0.2.0
   path: ^1.8.0
 environment:
-  sdk: '>=2.12.0 <3.0.0'
+  sdk: '>=2.12.0 <3.0.0'