[Enhancement] Nullsafety

.travis.yml

@@ -1,7 +1,7 @@
 language: dart
 sudo: required
 dart:
-  - stable
+  - beta
 addons:
   postgresql: "9.6"
 services:

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## 2.3.0
+
+- Migrate to null safety
+
 ## 2.2.0
 
 - Supporting Unix socket connections. (Thanks to [grillbiff](https://github.com/grillbiff),

lib/src/binary_codec.dart

@@ -28,13 +28,13 @@ final _hex = <String>[
   'f',
 ];
 
-class PostgresBinaryEncoder extends Converter<dynamic, Uint8List> {
+class PostgresBinaryEncoder extends Converter<dynamic, Uint8List?> {
   final PostgreSQLDataType _dataType;
 
   const PostgresBinaryEncoder(this._dataType);
 
   @override
-  Uint8List convert(dynamic value) {
+  Uint8List? convert(dynamic value) {
     if (value == null) {
       return null;
     }
@@ -169,7 +169,7 @@ class PostgresBinaryEncoder extends Converter<dynamic, Uint8List> {
                 'Invalid type for parameter value. Expected: String Got: ${value.runtimeType}');
           }
 
-          final hexBytes = (value as String)
+          final hexBytes = value
               .toLowerCase()
               .codeUnits
               .where((c) => c != _dashUnit)
@@ -199,9 +199,9 @@ class PostgresBinaryEncoder extends Converter<dynamic, Uint8List> {
           }
           return outBuffer;
         }
+      default:
+        throw PostgreSQLException('Unsupported datatype');
     }
-
-    throw PostgreSQLException('Unsupported datatype');
   }
 }
 
@@ -211,13 +211,13 @@ class PostgresBinaryDecoder extends Converter<Uint8List, dynamic> {
   final int typeCode;
 
   @override
-  dynamic convert(Uint8List value) {
-    final dataType = typeMap[typeCode];
-
+  dynamic convert(Uint8List? value) {
     if (value == null) {
       return null;
     }
 
+    final dataType = typeMap[typeCode];
+
     final buffer =
         ByteData.view(value.buffer, value.offsetInBytes, value.lengthInBytes);
 
@@ -277,16 +277,18 @@ class PostgresBinaryDecoder extends Converter<Uint8List, dynamic> {
 
           return buf.toString();
         }
-    }
-
-    // We'll try and decode this as a utf8 string and return that
-    // for many internal types, this is valid. If it fails,
-    // we just return the bytes and let the caller figure out what to
-    // do with it.
-    try {
-      return utf8.decode(value);
-    } catch (_) {
-      return value;
+      default:
+        {
+          // We'll try and decode this as a utf8 string and return that
+          // for many internal types, this is valid. If it fails,
+          // we just return the bytes and let the caller figure out what to
+          // do with it.
+          try {
+            return utf8.decode(value);
+          } catch (_) {
+            return value;
+          }
+        }
     }
   }
 

lib/src/client_messages.dart

@@ -42,11 +42,11 @@ void _applyStringToBuffer(UTF8BackedString string, ByteDataWriter buffer) {
 }
 
 class StartupMessage extends ClientMessage {
-  final UTF8BackedString _username;
+  final UTF8BackedString? _username;
   final UTF8BackedString _databaseName;
   final UTF8BackedString _timeZone;
 
-  StartupMessage(String databaseName, String timeZone, {String username})
+  StartupMessage(String databaseName, String timeZone, {String? username})
       : _databaseName = UTF8BackedString(databaseName),
         _timeZone = UTF8BackedString(timeZone),
         _username = username == null ? null : UTF8BackedString(username);
@@ -58,15 +58,15 @@ class StartupMessage extends ClientMessage {
 
     if (_username != null) {
       fixedLength += 5;
-      variableLength += _username.utf8Length + 1;
+      variableLength += _username!.utf8Length + 1;
     }
 
     buffer.writeInt32(fixedLength + variableLength);
     buffer.writeInt32(ClientMessage.ProtocolVersion);
 
     if (_username != null) {
       buffer.write(UTF8ByteConstants.user);
-      _applyStringToBuffer(_username, buffer);
+      _applyStringToBuffer(_username!, buffer);
     }
 
     buffer.write(UTF8ByteConstants.database);
@@ -83,7 +83,7 @@ class StartupMessage extends ClientMessage {
 }
 
 class AuthMD5Message extends ClientMessage {
-  UTF8BackedString _hashedAuthString;
+  UTF8BackedString? _hashedAuthString;
 
   AuthMD5Message(String username, String password, List<int> saltBytes) {
     final passwordHash = md5.convert('$password$username'.codeUnits).toString();
@@ -96,9 +96,9 @@ class AuthMD5Message extends ClientMessage {
   @override
   void applyToBuffer(ByteDataWriter buffer) {
     buffer.writeUint8(ClientMessage.PasswordIdentifier);
-    final length = 5 + _hashedAuthString.utf8Length;
+    final length = 5 + _hashedAuthString!.utf8Length;
     buffer.writeUint32(length);
-    _applyStringToBuffer(_hashedAuthString, buffer);
+    _applyStringToBuffer(_hashedAuthString!, buffer);
   }
 }
 
@@ -157,14 +157,14 @@ class BindMessage extends ClientMessage {
   final List<ParameterValue> _parameters;
   final UTF8BackedString _statementName;
   final int _typeSpecCount;
-  int _cachedLength;
+  int _cachedLength = -1;
 
   BindMessage(this._parameters, {String statementName = ''})
       : _typeSpecCount = _parameters.where((p) => p.isBinary).length,
         _statementName = UTF8BackedString(statementName);
 
   int get length {
-    if (_cachedLength == null) {
+    if (_cachedLength == -1) {
       var inputParameterElementCount = _parameters.length;
       if (_typeSpecCount == _parameters.length || _typeSpecCount == 0) {
         inputParameterElementCount = 1;
@@ -221,7 +221,7 @@ class BindMessage extends ClientMessage {
         buffer.writeInt32(-1);
       } else {
         buffer.writeInt32(p.length);
-        buffer.write(p.bytes);
+        buffer.write(p.bytes!);
       }
     });