Add tests

package/test/foundation/sheet_viewport_test.dart

@@ -0,0 +1,201 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:smooth_sheets/src/foundation/sheet_activity.dart';
+import 'package:smooth_sheets/src/foundation/sheet_extent.dart';
+import 'package:smooth_sheets/src/foundation/sheet_extent_scope.dart';
+import 'package:smooth_sheets/src/foundation/sheet_physics.dart';
+import 'package:smooth_sheets/src/foundation/sheet_status.dart';
+import 'package:smooth_sheets/src/foundation/sheet_viewport.dart';
+
+class _FakeNotificationContext extends Fake implements BuildContext {
+  @override
+  void dispatchNotification(Notification notification) {/* no-op */}
+}
+
+class _FakeSheetContext extends Fake implements SheetContext {
+  @override
+  final notificationContext = _FakeNotificationContext();
+}
+
+class _FakeSheetActivity extends SheetActivity {
+  _FakeSheetActivity({
+    this.shouldIgnorePointer = false,
+    this.status = SheetStatus.stable,
+  });
+
+  @override
+  final bool shouldIgnorePointer;
+
+  @override
+  final SheetStatus status;
+}
+
+class _FakeSheetExtent extends SheetExtent {
+  _FakeSheetExtent({
+    super.minExtent = const Extent.proportional(0.5),
+    super.maxExtent = const Extent.proportional(1),
+    super.physics = const ClampingSheetPhysics(),
+    this.createIdleActivity,
+  }) : super(context: _FakeSheetContext());
+
+  final ValueGetter<SheetActivity>? createIdleActivity;
+
+  @override
+  void applyNewContentSize(Size contentSize) {
+    super.applyNewContentSize(contentSize);
+    if (metrics.maybePixels == null) {
+      setPixels(maxExtent.resolve(metrics.contentSize));
+    }
+  }
+
+  @override
+  void goIdle() {
+    if (createIdleActivity case final builder?) {
+      beginActivity(builder());
+    } else {
+      super.goIdle();
+    }
+  }
+}
+
+class _TestWidget extends StatelessWidget {
+  const _TestWidget({
+    required this.extent,
+    this.background,
+    this.sheetContent,
+  });
+
+  final SheetExtent extent;
+  final Widget? sheetContent;
+  final Widget? background;
+
+  @override
+  Widget build(BuildContext context) {
+    final sheet = InheritedSheetExtentScope(
+      isPrimary: true,
+      extent: extent,
+      child: SheetViewport(
+        child: SheetContentViewport(
+          child: sheetContent ??
+              Container(
+                color: Colors.white,
+                width: double.infinity,
+                height: 500,
+              ),
+        ),
+      ),
+    );
+
+    return Directionality(
+      textDirection: TextDirection.ltr,
+      child: MediaQuery(
+        data: const MediaQueryData(),
+        child: switch (background) {
+          null => sheet,
+          final background => Stack(
+              children: [background, sheet],
+            )
+        },
+      ),
+    );
+  }
+}
+
+void main() {
+  group('Ignore pointer test:', () {
+    ({
+      SheetExtent extent,
+      Widget testWidget,
+      ValueGetter<bool> didTapForeground,
+      ValueGetter<bool> didTapBackgroundTop,
+      ValueGetter<bool> didTapBackgroundBottom,
+    }) boilerplate({
+      required bool shouldIgnorePointer,
+    }) {
+      var didTapForeground = false;
+      var didTapBackgroundTop = false;
+      var didTapBackgroundBottom = false;
+
+      final extent = _FakeSheetExtent(
+        createIdleActivity: () => _FakeSheetActivity(
+          shouldIgnorePointer: shouldIgnorePointer,
+        ),
+      );
+
+      final testWidget = _TestWidget(
+        extent: extent,
+        background: Column(
+          mainAxisAlignment: MainAxisAlignment.spaceBetween,
+          children: [
+            TextButton(
+              onPressed: () => didTapBackgroundTop = true,
+              child: const Text('Background top'),
+            ),
+            TextButton(
+              onPressed: () => didTapBackgroundBottom = true,
+              child: const Text('Background bottom'),
+            ),
+          ],
+        ),
+        sheetContent: Container(
+          alignment: Alignment.center,
+          color: Colors.white,
+          width: double.infinity,
+          height: 500,
+          child: TextButton(
+            onPressed: () => didTapForeground = true,
+            child: const Text('Foreground'),
+          ),
+        ),
+      );
+
+      return (
+        extent: extent,
+        testWidget: testWidget,
+        didTapForeground: () => didTapForeground,
+        didTapBackgroundTop: () => didTapBackgroundTop,
+        didTapBackgroundBottom: () => didTapBackgroundBottom,
+      );
+    }
+
+    testWidgets(
+      'pointer events on a sheet should be ignored if activity says to do so',
+      (tester) async {
+        final env = boilerplate(shouldIgnorePointer: true);
+        await tester.pumpWidget(env.testWidget);
+        await tester.tap(find.text('Foreground'), warnIfMissed: false);
+        expect(env.didTapForeground(), isFalse);
+      },
+    );
+
+    testWidgets(
+      'content in a sheet should receive pointer events if activity allows',
+      (tester) async {
+        final env = boilerplate(shouldIgnorePointer: false);
+        await tester.pumpWidget(env.testWidget);
+        await tester.tap(find.text('Foreground'), warnIfMissed: false);
+        expect(env.didTapForeground(), isTrue);
+      },
+    );
+
+    testWidgets(
+      'content obscured by a sheet should never receive pointer events',
+      (tester) async {
+        final env = boilerplate(shouldIgnorePointer: true);
+        await tester.pumpWidget(env.testWidget);
+        await tester.tap(find.text('Background bottom'), warnIfMissed: false);
+        expect(env.didTapBackgroundBottom(), isFalse);
+      },
+    );
+
+    testWidgets(
+      'content not obscured by a sheet should always receive pointer events',
+      (tester) async {
+        final env = boilerplate(shouldIgnorePointer: true);
+        await tester.pumpWidget(env.testWidget);
+        await tester.tap(find.text('Background top'), warnIfMissed: false);
+        expect(env.didTapBackgroundTop(), isTrue);
+      },
+    );
+  });
+}