Adding tests

+import 'package:flutter/material.dart';
+import 'package:flutter_screenutil/flutter_screenutil.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import 'home.test.dart';
+
+void main() {
+  const smallerDeviceSize = Size(300, 600);
+  const smallerDeviceData = MediaQueryData(size: smallerDeviceSize);
+
+  const biggerDeviceSize = Size(500, 900);
+  const biggerDeviceData = MediaQueryData(size: biggerDeviceSize);
+
+  const uiSize = Size(470, 740);
+
+  group('[Test calculations]', () {
+    test('Test smaller size', () {
+      ScreenUtil.configure(
+        data: smallerDeviceData,
+        designSize: uiSize,
+        minTextAdapt: true,
+        splitScreenMode: false,
+      );
+
+      expect(1.w, smallerDeviceSize.width / uiSize.width);
+      expect(1.w < 1, true);
+      expect(1.h, smallerDeviceSize.height / uiSize.height);
+      expect(1.h < 1, true);
+    });
+
+    test('Test bigger size', () {
+      ScreenUtil.configure(
+        data: biggerDeviceData,
+        designSize: uiSize,
+        minTextAdapt: true,
+        splitScreenMode: false,
+      );
+
+      expect(1.w, biggerDeviceSize.width / uiSize.width);
+      expect(1.w > 1, true);
+      expect(1.h, biggerDeviceSize.height / uiSize.height);
+      expect(1.h > 1, true);
+    });
+  });
+
+  group('[Test overflow]', () {
+    testWidgets('Test overflow width', (tester) async {
+      await tester.pumpWidget(ScreenUtilInit(
+        designSize: uiSize,
+        child: MaterialApp(home: WidgetTest(width: () => uiSize.width.w)),
+      ));
+
+      // Wait until all widget rendered
+      await tester.pumpAndSettle();
+
+      // a Text widget must be present
+      expect(find.text('Test'), findsOneWidget);
+    });
+
+    testWidgets('Test overflow height', (tester) async {
+      await tester.pumpWidget(ScreenUtilInit(
+        designSize: uiSize,
+        child: MaterialApp(home: WidgetTest(height: () => uiSize.height.h)),
+      ));
+
+      // Wait until all widget rendered
+      await tester.pumpAndSettle();
+
+      // a Text widget must be present
+      expect(find.text('Test'), findsOneWidget);
+    });
+  });
+
+  testWidgets('[Rebuilding]', (tester) async {
+    final textFieldKey = UniqueKey();
+    final buildCountNotifier = ValueNotifier(0);
+    final focusNode = FocusNode();
+
+    Finder textField() => find.byKey(textFieldKey);
+
+    await tester.pumpWidget(ScreenUtilInit(
+      designSize: uiSize,
+      rebuildFactor: RebuildFactors.always,
+      child: MaterialApp(
+        home: Scaffold(
+          body: Builder(
+            builder: (context) {
+              buildCountNotifier.value += 1;
+
+              assert(uiSize.width.w == MediaQuery.of(context).size.width);
+
+              return SizedBox(
+                width: 1.sw,
+                child: Column(
+                  children: [
+                    ValueListenableBuilder<int>(
+                      valueListenable: buildCountNotifier,
+                      builder: (_, count, __) => Text('Built count: $count'),
+                    ),
+                    TextField(
+                      key: textFieldKey,
+                      focusNode: focusNode,
+                    ),
+                  ],
+                ),
+              );
+            },
+          ),
+        ),
+      ),
+    ));
+
+    await tester.pumpAndSettle();
+    expect(buildCountNotifier.value, 1);
+
+    expect(textField(), findsOneWidget);
+    expect(focusNode.hasFocus, false);
+
+    await tester.tap(textField()).then((_) => tester.pumpAndSettle());
+    expect(textField(), findsOneWidget);
+    expect(focusNode.hasFocus, true);
+    expect(buildCountNotifier.value, 1);
+
+    // Simulate keyboard
+    tester.view.viewInsets = FakeViewPadding(bottom: 20);
+
+    await tester.pumpAndSettle();
+    expect(focusNode.hasFocus, true);
+    expect(buildCountNotifier.value, 1);
+  });
+}

+import 'package:flutter/widgets.dart';
+
+class WidgetTest extends StatelessWidget {
+  const WidgetTest({
+    super.key,
+    this.width = _zero,
+    this.height = _zero,
+  });
+
+  final double Function() width;
+  final double Function() height;
+
+  @override
+  Widget build(BuildContext context) {
+    return LayoutBuilder(
+      builder: (_, c) {
+        final w = width(), h = height();
+
+        if (c.biggest >= Size(w, h)) {
+          return const Text('Test');
+        }
+
+        throw Error();
+      },
+    );
+  }
+
+  static double _zero() => 0;
+}