add scope.get

lib/src/scopes/errors/scope_value_not_exposed_error.dart

@@ -0,0 +1,13 @@
+
+class ScopeValueNotExposedError<T> extends Error {
+
+  ScopeValueNotExposedError(Object? name): _name = name;
+
+  final Object? _name;
+
+  @override
+  String toString() {
+    final header = _name == null ? '$T' : '$T $_name';
+    return '`$header` is not exposed in current scope';
+  }
+}

lib/src/scopes/scope_methods/scope_get.dart

@@ -1,3 +1,4 @@
+import '../errors/scope_value_not_exposed_error.dart';
 
 abstract class ScopeGet {
   T? getOrNull<T>({
@@ -7,3 +8,12 @@ abstract class ScopeGet {
     Object? name,
   });
 }
+
+extension ScopeGetX on ScopeGet {
+
+  T get<T>({
+    Object? name,
+  }) => has<T>(name: name)
+    ? getOrNull<T>(name: name) as T
+    : throw ScopeValueNotExposedError<T>(name);
+}

lib/src/scopes/scopes.dart

@@ -1,5 +1,6 @@
 
 export 'configurables/configurable.dart';
+export 'errors/scope_value_not_exposed_error.dart';
 export 'scope_methods/scope_get.dart';
 export 'scope_methods/scope_expose.dart';
 export 'scope_methods/scope_push.dart';

test/scopes/scope_methods/scope_get_test.dart

@@ -0,0 +1,78 @@
+import 'package:test/test.dart';
+import 'package:scopes/scopes.dart';
+
+import '../../toolbox/mock_configurable.dart';
+
+void main() {
+
+  test('`scope.get` return value if value exposed', () async {
+
+    final scope = await Scope.root([
+      MockConfigurable((scope) {
+        scope.expose<String>(expose: () => 'a');
+      }),
+    ]);
+
+    final value = scope.get<String>();
+
+    expect(value, 'a');
+
+  });
+
+  test('`scope.get` throws if value not exposed', () async {
+
+    final scope = await Scope.root([]);
+
+    expect(
+      () {
+        scope.get<String>();
+      },
+      throwsA(
+        isA<ScopeValueNotExposedError<String>>()
+          .having(
+            (error) => '$error',
+            'description',
+            contains('`String` is not exposed in current scope'),
+          ),
+      )
+    );
+
+  });
+
+  test('`scope.get` return value if value exposed with name', () async {
+
+    final scope = await Scope.root([
+      MockConfigurable((scope) {
+        scope.expose<String>(
+          name: 'state',
+          expose: () => 'a',
+        );
+      }),
+    ]);
+
+    final value = scope.get<String>(name: 'state');
+
+    expect(value, 'a');
+
+  });
+
+  test('`scope.get` throws if value not exposed with name', () async {
+
+    final scope = await Scope.root([]);
+
+    expect(
+      () {
+        scope.get<String>(name: 'state');
+      },
+      throwsA(
+        isA<ScopeValueNotExposedError<String>>()
+          .having(
+            (error) => '$error',
+            'description',
+            contains('`String state` is not exposed in current scope'),
+          ),
+      )
+    );
+
+  });
+}

test/scopes/scopes_test.dart

@@ -1,10 +1,12 @@
 
 import 'scope_methods/disposable_test.dart' as disposable_test;
+import 'scope_methods/scope_get_test.dart' as scope_get_test;
 import 'scope_methods/scope_push_test.dart' as scope_push_test;
 import 'scopes/scope_test.dart' as scope_test;
 
 void main() {
   disposable_test.main();
+  scope_get_test.main();
   scope_push_test.main();
   scope_test.main();
 }