diff --git a/packages/flutter/lib/src/foundation/serialization.dart b/packages/flutter/lib/src/foundation/serialization.dart
index 753de146e70..822d916aa01 100644
--- a/packages/flutter/lib/src/foundation/serialization.dart
+++ b/packages/flutter/lib/src/foundation/serialization.dart
@@ -103,9 +103,8 @@ class WriteBuffer {
 /// The byte order used is [Endianness.HOST_ENDIAN] throughout.
 class ReadBuffer {
   /// Creates a [ReadBuffer] for reading from the specified [data].
-  ReadBuffer(this.data) {
-    assert(data != null);
-  }
+  ReadBuffer(this.data)
+    : assert(data != null);
 
   /// The underlying data being read.
   final ByteData data;
diff --git a/packages/flutter/lib/src/material/material.dart b/packages/flutter/lib/src/material/material.dart
index a03aa5ff6ee..fc92a7e1425 100644
--- a/packages/flutter/lib/src/material/material.dart
+++ b/packages/flutter/lib/src/material/material.dart
@@ -275,9 +275,12 @@ class _MaterialState extends State<Material> with TickerProviderStateMixin {
 const Duration _kHighlightFadeDuration = const Duration(milliseconds: 200);
 
 class _RenderInkFeatures extends RenderProxyBox implements MaterialInkController {
-  _RenderInkFeatures({ RenderBox child, @required this.vsync, this.color }) : super(child) {
-    assert(vsync != null);
-  }
+  _RenderInkFeatures({
+    RenderBox child,
+    @required this.vsync,
+    this.color,
+  }) : assert(vsync != null),
+       super(child);
 
   // This class should exist in a 1:1 relationship with a MaterialState object,
   // since there's no current support for dynamically changing the ticker
diff --git a/packages/flutter/lib/src/painting/box_painter.dart b/packages/flutter/lib/src/painting/box_painter.dart
index 4600841df91..d176a87ad4d 100644
--- a/packages/flutter/lib/src/painting/box_painter.dart
+++ b/packages/flutter/lib/src/painting/box_painter.dart
@@ -1659,9 +1659,9 @@ class BoxDecoration extends Decoration {
 
 /// An object that paints a [BoxDecoration] into a canvas.
 class _BoxDecorationPainter extends BoxPainter {
-  _BoxDecorationPainter(@required this._decoration, VoidCallback onChange) : super(onChange) {
-    assert(_decoration != null);
-  }
+  _BoxDecorationPainter(@required this._decoration, VoidCallback onChange)
+    : assert(_decoration != null),
+      super(onChange);
 
   final BoxDecoration _decoration;
 
diff --git a/packages/flutter/lib/src/painting/flutter_logo.dart b/packages/flutter/lib/src/painting/flutter_logo.dart
index 97ba120a0fb..3652febb51c 100644
--- a/packages/flutter/lib/src/painting/flutter_logo.dart
+++ b/packages/flutter/lib/src/painting/flutter_logo.dart
@@ -219,9 +219,10 @@ class FlutterLogoDecoration extends Decoration {
 
 /// An object that paints a [BoxDecoration] into a canvas.
 class _FlutterLogoPainter extends BoxPainter {
-  _FlutterLogoPainter(this._config) : super(null) {
-    assert(_config != null);
-    assert(_config.debugAssertIsValid());
+  _FlutterLogoPainter(this._config)
+    : assert(_config != null),
+      assert(_config.debugAssertIsValid()),
+      super(null) {
     _prepareText();
   }
 
diff --git a/packages/flutter/lib/src/painting/text_painter.dart b/packages/flutter/lib/src/painting/text_painter.dart
index a3e77426e42..8c7e458f6c4 100644
--- a/packages/flutter/lib/src/painting/text_painter.dart
+++ b/packages/flutter/lib/src/painting/text_painter.dart
@@ -41,10 +41,13 @@ class TextPainter {
     double textScaleFactor: 1.0,
     int maxLines,
     String ellipsis,
-  }) : _text = text, _textAlign = textAlign, _textScaleFactor = textScaleFactor, _maxLines = maxLines, _ellipsis = ellipsis {
-    assert(text == null || text.debugAssertIsValid());
-    assert(textScaleFactor != null);
-  }
+  }) : assert(text == null || text.debugAssertIsValid()),
+       assert(textScaleFactor != null),
+       _text = text,
+       _textAlign = textAlign,
+       _textScaleFactor = textScaleFactor,
+       _maxLines = maxLines,
+       _ellipsis = ellipsis;
 
   ui.Paragraph _paragraph;
   bool _needsLayout = true;
diff --git a/packages/flutter/lib/src/physics/clamped_simulation.dart b/packages/flutter/lib/src/physics/clamped_simulation.dart
index 82fe080310f..854936f5ccb 100644
--- a/packages/flutter/lib/src/physics/clamped_simulation.dart
+++ b/packages/flutter/lib/src/physics/clamped_simulation.dart
@@ -26,11 +26,9 @@ class ClampedSimulation extends Simulation {
     this.xMax: double.INFINITY,
     this.dxMin: double.NEGATIVE_INFINITY,
     this.dxMax: double.INFINITY
-  }) {
-    assert(simulation != null);
-    assert(xMax >= xMin);
-    assert(dxMax >= dxMin);
-  }
+  }) : assert(simulation != null),
+       assert(xMax >= xMin),
+       assert(dxMax >= dxMin);
 
   /// The simulation being clamped. Calls to [x], [dx], and [isDone] are
   /// forwarded to the simulation.
diff --git a/packages/flutter/lib/src/physics/friction_simulation.dart b/packages/flutter/lib/src/physics/friction_simulation.dart
index 10cf766e22c..8fa5cf18d8f 100644
--- a/packages/flutter/lib/src/physics/friction_simulation.dart
+++ b/packages/flutter/lib/src/physics/friction_simulation.dart
@@ -105,9 +105,8 @@ class BoundedFrictionSimulation extends FrictionSimulation {
     double velocity,
     this._minX,
     this._maxX
-  ) : super(drag, position, velocity) {
-    assert(position.clamp(_minX, _maxX) == position);
-  }
+  ) : assert(position.clamp(_minX, _maxX) == position),
+      super(drag, position, velocity);
 
   final double _minX;
   final double _maxX;
diff --git a/packages/flutter/lib/src/physics/gravity_simulation.dart b/packages/flutter/lib/src/physics/gravity_simulation.dart
index b75eb93bded..5e75c4b4aa8 100644
--- a/packages/flutter/lib/src/physics/gravity_simulation.dart
+++ b/packages/flutter/lib/src/physics/gravity_simulation.dart
@@ -28,16 +28,15 @@ class GravitySimulation extends Simulation {
     double distance,
     double endDistance,
     double velocity
-  ) : _a = acceleration,
+  ) : assert(acceleration != null),
+      assert(distance != null),
+      assert(velocity != null),
+      assert(endDistance != null),
+      assert(endDistance >= 0),
+      _a = acceleration,
       _x = distance,
       _v = velocity,
-      _end = endDistance {
-    assert(acceleration != null);
-    assert(distance != null);
-    assert(velocity != null);
-    assert(endDistance != null);
-    assert(endDistance >= 0);
-  }
+      _end = endDistance;
 
   final double _x;
   final double _v;
diff --git a/packages/flutter/lib/src/services/image_stream.dart b/packages/flutter/lib/src/services/image_stream.dart
index baa013e0461..f6a1ca57253 100644
--- a/packages/flutter/lib/src/services/image_stream.dart
+++ b/packages/flutter/lib/src/services/image_stream.dart
@@ -237,8 +237,8 @@ class OneFrameImageStreamCompleter extends ImageStreamCompleter {
   /// argument on [FlutterErrorDetails] set to true, meaning that by default the
   /// message is only dumped to the console in debug mode (see [new
   /// FlutterErrorDetails]).
-  OneFrameImageStreamCompleter(Future<ImageInfo> image, { InformationCollector informationCollector }) {
-    assert(image != null);
+  OneFrameImageStreamCompleter(Future<ImageInfo> image, { InformationCollector informationCollector })
+    : assert(image != null) {
     image.then<Null>(setImage, onError: (dynamic error, StackTrace stack) {
       FlutterError.reportError(new FlutterErrorDetails(
         exception: error,
diff --git a/packages/flutter/lib/src/services/message_codec.dart b/packages/flutter/lib/src/services/message_codec.dart
index dec6db4c5c8..22691f44e11 100644
--- a/packages/flutter/lib/src/services/message_codec.dart
+++ b/packages/flutter/lib/src/services/message_codec.dart
@@ -35,9 +35,8 @@ abstract class MessageCodec<T> {
 class MethodCall {
   /// Creates a [MethodCall] representing the invocation of [method] with the
   /// specified [arguments].
-  MethodCall(this.method, [this.arguments]) {
-    assert(method != null);
-  }
+  MethodCall(this.method, [this.arguments])
+    : assert(method != null);
 
   /// The name of the method to be called.
   final String method;
@@ -148,9 +147,7 @@ class PlatformException implements Exception {
     @required this.code,
     this.message,
     this.details,
-  }) {
-    assert(code != null);
-  }
+  }) : assert(code != null);
 
   /// An error code.
   final String code;
diff --git a/packages/flutter/lib/src/services/text_input.dart b/packages/flutter/lib/src/services/text_input.dart
index e1c4ca87554..a982d9bd80e 100644
--- a/packages/flutter/lib/src/services/text_input.dart
+++ b/packages/flutter/lib/src/services/text_input.dart
@@ -224,9 +224,9 @@ abstract class TextInputClient {
 ///
 ///  * [TextInput.attach]
 class TextInputConnection {
-  TextInputConnection._(this._client) : _id = _nextId++ {
-    assert(_client != null);
-  }
+  TextInputConnection._(this._client)
+    : assert(_client != null),
+      _id = _nextId++;
 
   static int _nextId = 1;
   final int _id;