format tidy code structure

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 - **Incompatible**: API about `ReContext` changed.
 - Use `builder` instead of `ReContext`, which is conciser.
+- Optimize tests and tidy code structure.
 
 ## 0.6.0
 

lib/src/context.dart

@@ -9,3 +9,20 @@ extension WrapContext on Widget {
 /// An encapsulation of [Builder], which makes it conciser.
 Widget builder(Widget Function(BuildContext context) builder) =>
     Builder(builder: builder);
+
+extension WrapMedia on Widget {
+  Widget wrapMedia(MediaQueryData data) => MediaQuery(data: data, child: this);
+
+  /// Ensure the widget is wrapped by a [MediaQuery] ancestor.
+  ///
+  /// Provide environment for [MediaQuery.of] that many widgets need,
+  /// including the [Text] widget. Without such ancestor,
+  /// once displaying a [Text],
+  /// it will throw exceptions.
+  Widget ensureMedia(BuildContext context) {
+    final media = MediaQuery.maybeOf(context);
+    return media == null
+        ? wrapMedia(MediaQueryData.fromView(View.of(context)))
+        : this;
+  }
+}

lib/src/text.dart

@@ -1,6 +1,6 @@
 import 'package:flutter/widgets.dart';
 
-import 'media.dart';
+import 'context.dart';
 
 extension WrapDirectionality on Widget {
   Widget wrapDirectionality(TextDirection direction) => Directionality(

lib/wrap.dart

@@ -5,6 +5,5 @@ export 'src/decorate.dart';
 export 'src/handler.dart';
 export 'src/inherit.dart';
 export 'src/list.dart';
-export 'src/media.dart';
 export 'src/size.dart';
 export 'src/text.dart';