[cfe] Add test for covariant late final fields

Closes #40805

Change-Id: I896bce935803a951cfb8c9c0d0f70a6227de2413
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/139464
Reviewed-by: Jens Johansen <jensj@google.com>
Commit-Queue: Johnni Winther <johnniwinther@google.com>

pkg/front_end/testcases/late_lowering/issue40805.dart

@@ -0,0 +1,15 @@
+// Copyright (c) 2020, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+main() {
+  D().x = 3.14;
+}
+
+class C {
+  covariant late final int x;
+}
+
+class D extends C {
+  set x(num value) { super.x = value.toInt(); }
+}

pkg/front_end/testcases/late_lowering/issue40805.dart.outline.expect

@@ -0,0 +1,19 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+class C extends core::Object {
+  covariant field core::int? _#C#x;
+  synthetic constructor •() → self::C
+    ;
+  get x() → core::int;
+  set x(core::int #t1) → void;
+}
+class D extends self::C {
+  synthetic constructor •() → self::D
+    ;
+  set x(core::num value) → void
+    ;
+}
+static method main() → dynamic
+  ;

pkg/front_end/testcases/late_lowering/issue40805.dart.strong.expect

@@ -0,0 +1,29 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+import "dart:_internal" as _in;
+
+class C extends core::Object {
+  covariant field core::int? _#C#x = null;
+  synthetic constructor •() → self::C
+    : super core::Object::•()
+    ;
+  get x() → core::int
+    return let final core::int? #t1 = this.{self::C::_#C#x} in #t1.==(null) ?{core::int} throw new _in::LateInitializationErrorImpl::•("Field 'x' has not been initialized.") : #t1{core::int};
+  set x(core::int #t2) → void
+    if(this.{self::C::_#C#x}.==(null))
+      this.{self::C::_#C#x} = #t2;
+    else
+      throw new _in::LateInitializationErrorImpl::•("Field 'x' has already been initialized.");
+}
+class D extends self::C {
+  synthetic constructor •() → self::D
+    : super self::C::•()
+    ;
+  set x(core::num value) → void {
+    super.{self::C::x} = value.{core::num::toInt}();
+  }
+}
+static method main() → dynamic {
+  new self::D::•().{self::D::x} = 3.14;
+}

pkg/front_end/testcases/late_lowering/issue40805.dart.strong.transformed.expect

@@ -0,0 +1,29 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+import "dart:_internal" as _in;
+
+class C extends core::Object {
+  covariant field core::int? _#C#x = null;
+  synthetic constructor •() → self::C
+    : super core::Object::•()
+    ;
+  get x() → core::int
+    return let final core::int? #t1 = this.{self::C::_#C#x} in #t1.==(null) ?{core::int} throw new _in::LateInitializationErrorImpl::•("Field 'x' has not been initialized.") : #t1{core::int};
+  set x(core::int #t2) → void
+    if(this.{self::C::_#C#x}.==(null))
+      this.{self::C::_#C#x} = #t2;
+    else
+      throw new _in::LateInitializationErrorImpl::•("Field 'x' has already been initialized.");
+}
+class D extends self::C {
+  synthetic constructor •() → self::D
+    : super self::C::•()
+    ;
+  set x(core::num value) → void {
+    super.{self::C::x} = value.{core::num::toInt}();
+  }
+}
+static method main() → dynamic {
+  new self::D::•().{self::D::x} = 3.14;
+}

pkg/front_end/testcases/late_lowering/issue40805.dart.weak.expect

@@ -0,0 +1,29 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+import "dart:_internal" as _in;
+
+class C extends core::Object {
+  covariant field core::int? _#C#x = null;
+  synthetic constructor •() → self::C
+    : super core::Object::•()
+    ;
+  get x() → core::int
+    return let final core::int? #t1 = this.{self::C::_#C#x} in #t1.==(null) ?{core::int} throw new _in::LateInitializationErrorImpl::•("Field 'x' has not been initialized.") : #t1{core::int};
+  set x(core::int #t2) → void
+    if(this.{self::C::_#C#x}.==(null))
+      this.{self::C::_#C#x} = #t2;
+    else
+      throw new _in::LateInitializationErrorImpl::•("Field 'x' has already been initialized.");
+}
+class D extends self::C {
+  synthetic constructor •() → self::D
+    : super self::C::•()
+    ;
+  set x(core::num value) → void {
+    super.{self::C::x} = value.{core::num::toInt}();
+  }
+}
+static method main() → dynamic {
+  new self::D::•().{self::D::x} = 3.14;
+}

pkg/front_end/testcases/late_lowering/issue40805.dart.weak.transformed.expect

@@ -0,0 +1,29 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+import "dart:_internal" as _in;
+
+class C extends core::Object {
+  covariant field core::int? _#C#x = null;
+  synthetic constructor •() → self::C
+    : super core::Object::•()
+    ;
+  get x() → core::int
+    return let final core::int? #t1 = this.{self::C::_#C#x} in #t1.==(null) ?{core::int} throw new _in::LateInitializationErrorImpl::•("Field 'x' has not been initialized.") : #t1{core::int};
+  set x(core::int #t2) → void
+    if(this.{self::C::_#C#x}.==(null))
+      this.{self::C::_#C#x} = #t2;
+    else
+      throw new _in::LateInitializationErrorImpl::•("Field 'x' has already been initialized.");
+}
+class D extends self::C {
+  synthetic constructor •() → self::D
+    : super self::C::•()
+    ;
+  set x(core::num value) → void {
+    super.{self::C::x} = value.{core::num::toInt}();
+  }
+}
+static method main() → dynamic {
+  new self::D::•().{self::D::x} = 3.14;
+}

pkg/front_end/testcases/nnbd/issue40805.dart

@@ -0,0 +1,15 @@
+// Copyright (c) 2020, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+main() {
+  D().x = 3.14;
+}
+
+class C {
+  covariant late final int x;
+}
+
+class D extends C {
+  set x(num value) { super.x = value.toInt(); }
+}

pkg/front_end/testcases/nnbd/issue40805.dart.outline.expect

@@ -0,0 +1,17 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+class C extends core::Object {
+  late covariant final [setter] field core::int x;
+  synthetic constructor •() → self::C
+    ;
+}
+class D extends self::C {
+  synthetic constructor •() → self::D
+    ;
+  set x(covariant core::num value) → void
+    ;
+}
+static method main() → dynamic
+  ;

pkg/front_end/testcases/nnbd/issue40805.dart.strong.expect

@@ -0,0 +1,21 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+class C extends core::Object {
+  late covariant final [setter] field core::int x;
+  synthetic constructor •() → self::C
+    : super core::Object::•()
+    ;
+}
+class D extends self::C {
+  synthetic constructor •() → self::D
+    : super self::C::•()
+    ;
+  set x(covariant core::num value) → void {
+    super.{self::C::x} = value.{core::num::toInt}();
+  }
+}
+static method main() → dynamic {
+  new self::D::•().{self::D::x} = 3.14;
+}

pkg/front_end/testcases/nnbd/issue40805.dart.strong.transformed.expect

@@ -0,0 +1,21 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+class C extends core::Object {
+  late covariant final [setter] field core::int x;
+  synthetic constructor •() → self::C
+    : super core::Object::•()
+    ;
+}
+class D extends self::C {
+  synthetic constructor •() → self::D
+    : super self::C::•()
+    ;
+  set x(covariant core::num value) → void {
+    super.{self::C::x} = value.{core::num::toInt}();
+  }
+}
+static method main() → dynamic {
+  new self::D::•().{self::D::x} = 3.14;
+}

pkg/front_end/testcases/nnbd/issue40805.dart.weak.expect

@@ -0,0 +1,21 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+class C extends core::Object {
+  late covariant final [setter] field core::int x;
+  synthetic constructor •() → self::C
+    : super core::Object::•()
+    ;
+}
+class D extends self::C {
+  synthetic constructor •() → self::D
+    : super self::C::•()
+    ;
+  set x(covariant core::num value) → void {
+    super.{self::C::x} = value.{core::num::toInt}();
+  }
+}
+static method main() → dynamic {
+  new self::D::•().{self::D::x} = 3.14;
+}

pkg/front_end/testcases/nnbd/issue40805.dart.weak.transformed.expect

@@ -0,0 +1,21 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+
+class C extends core::Object {
+  late covariant final [setter] field core::int x;
+  synthetic constructor •() → self::C
+    : super core::Object::•()
+    ;
+}
+class D extends self::C {
+  synthetic constructor •() → self::D
+    : super self::C::•()
+    ;
+  set x(covariant core::num value) → void {
+    super.{self::C::x} = value.{core::num::toInt}();
+  }
+}
+static method main() → dynamic {
+  new self::D::•().{self::D::x} = 3.14;
+}

pkg/front_end/testcases/text_serialization.status

@@ -1221,6 +1221,7 @@ late_lowering/instance_nullable_final_field_without_initializer: TextSerializati
 late_lowering/issue40093: TextSerializationFailure
 late_lowering/issue40373: TextSerializationFailure
 late_lowering/issue40373b: TextSerializationFailure
+late_lowering/issue40805: TextSerializationFailure
 late_lowering/late_field_inference: TextSerializationFailure
 late_lowering/late_field_with_initializer: TextSerializationFailure
 late_lowering/late_field_without_initializer: TextSerializationFailure
@@ -1277,6 +1278,7 @@ nnbd/issue40093: TextSerializationFailure
 nnbd/issue40134: TextSerializationFailure
 nnbd/issue40512/issue40512: TextSerializationFailure
 nnbd/issue40600: TextSerializationFailure
+nnbd/issue40805: TextSerializationFailure
 nnbd/issue_39286: TextSerializationFailure
 nnbd/issue_39286_2: TextSerializationFailure
 nnbd/late: TextSerializationFailure