Additional tests for deferred function literals.

These tests exercise the "deferred type inference of function
literals" part of dart-lang/language#731
(improved inference for fold etc.) for super-constructor invocations
and redirecting constructor invocations, both of which have their own
code paths in the analyzer.

Change-Id: I6877ac3c07a3cca31550ba74d941d250c8410cfd
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/241987
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Samuel Rawlins <srawlins@google.com>
Reviewed-by: Chloe Stefantsova <cstefantsova@google.com>

pkg/analyzer/test/src/dart/resolution/type_inference/inference_update_1_test.dart

@@ -356,4 +356,34 @@ void f({required void Function() g, Object? x}) {}
     // regardless of whether the experiment is enabled.
     assertType(findNode.simple('i; // (2)'), 'int?');
   }
+
+  test_write_capture_deferred_redirecting_constructor() async {
+    await assertNoErrorsInCode('''
+class C {
+  C(int? i) : this.other(i!, () { i = null; }, i);
+  C.other(Object? x, void Function() g, Object? y);
+}
+''');
+    // With the feature enabled, analysis of the closure is deferred until after
+    // all the other arguments to `this.other`, so the `i` passed to `y` is not
+    // yet write captured and retains its promoted value.  With the experiment
+    // disabled, it is write captured immediately.
+    assertType(findNode.simple('i);'), _isEnabled ? 'int' : 'int?');
+  }
+
+  test_write_capture_deferred_super_constructor() async {
+    await assertNoErrorsInCode('''
+class B {
+  B(Object? x, void Function() g, Object? y);
+}
+class C extends B {
+  C(int? i) : super(i!, () { i = null; }, i);
+}
+''');
+    // With the feature enabled, analysis of the closure is deferred until after
+    // all the other arguments to `this.other`, so the `i` passed to `y` is not
+    // yet write captured and retains its promoted value.  With the experiment
+    // disabled, it is write captured immediately.
+    assertType(findNode.simple('i);'), _isEnabled ? 'int' : 'int?');
+  }
 }

tests/language/inference_update_1/write_capture_deferral_disabled_test.dart

@@ -52,4 +52,19 @@ withIdentical_rhs(int? i) {
   }
 }
 
+class B {
+  B(Object? x, void Function() g, Object? y);
+  B.redirectingConstructorInvocation(int? i)
+      : this(i!, () {
+          i = null;
+        }, i..expectStaticType<Exactly<int?>>());
+}
+
+class C extends B {
+  C.superConstructorInvocation(int? i)
+      : super(i!, () {
+          i = null;
+        }, i..expectStaticType<Exactly<int?>>());
+}
+
 main() {}

tests/language/inference_update_1/write_capture_deferral_enabled_test.dart

@@ -52,4 +52,19 @@ withIdentical_rhs(int? i) {
   }
 }
 
+class B {
+  B(Object? x, void Function() g, Object? y);
+  B.redirectingConstructorInvocation(int? i)
+      : this(i!, () {
+          i = null;
+        }, i..expectStaticType<Exactly<int>>());
+}
+
+class C extends B {
+  C.superConstructorInvocation(int? i)
+      : super(i!, () {
+          i = null;
+        }, i..expectStaticType<Exactly<int>>());
+}
+
 main() {}