[cfe] Add conditional import tests

Change-Id: If309f74ab7420e933c0942388780b57e8c3d63dc
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/221622
Reviewed-by: Chloe Stefantsova <cstefantsova@google.com>
Commit-Queue: Johnni Winther <johnniwinther@google.com>

pkg/front_end/test/spell_checking_list_tests.txt

@@ -158,6 +158,7 @@ cb
 cc
 ccc
 cell
+certificate
 cf
 characteristics
 charset

pkg/front_end/testcases/dart2js/conditional_import.dart

@@ -0,0 +1,37 @@
+// Copyright (c) 2021, 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.
+
+// All three libraries have an HttpRequest class.
+import "conditional_import.dart"
+    if (dart.library.io) "dart:io"
+    if (dart.library.html) "dart:html" as a;
+
+// All three libraries have an HttpRequest class.
+import "conditional_import.dart" if (dart.library.foo) "dart:foo" as b;
+
+class HttpRequest {}
+
+testA(a.HttpRequest request) {
+  request.certificate; // error (from dart:io)
+  request.response; // ok (from dart:io and dart:html)
+  request.readyState; // ok (from dart:html)
+  request.hashCode; // ok
+}
+
+testB(b.HttpRequest request) {
+  request.certificate; // error
+  request.response; // error
+  request.readyState; // error
+  request.hashCode; // ok
+}
+
+void main() {
+  expect(false, const bool.fromEnvironment("dart.library.io"));
+  expect(true, const bool.fromEnvironment("dart.library.html"));
+  expect(false, const bool.fromEnvironment("dart.library.foo"));
+}
+
+expect(expected, actual) {
+  if (expected != actual) throw 'Expected $expected, actual $actual';
+}

pkg/front_end/testcases/dart2js/conditional_import.dart.strong.expect

@@ -0,0 +1,84 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'dart:_http'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // ok (from dart:html)
+//           ^^^^^^^^^^
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+//   request.certificate; // error
+//           ^^^^^^^^^^^
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+//   request.response; // error
+//           ^^^^^^^^
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // error
+//           ^^^^^^^^^^
+//
+import self as self;
+import "dart:core" as core;
+import "dart:_http" as _ht;
+import "dart:io" as io;
+
+import "dart:io" as a;
+import "org-dartlang-testcase:///conditional_import.dart" as b;
+
+class HttpRequest extends core::Object {
+  synthetic constructor •() → self::HttpRequest
+    : super core::Object::•()
+    ;
+  static method _#new#tearOff() → self::HttpRequest
+    return new self::HttpRequest::•();
+}
+static method testA(_ht::HttpRequest request) → dynamic {
+  request.{_ht::HttpRequest::certificate}{io::X509Certificate?};
+  request.{_ht::HttpRequest::response}{_ht::HttpResponse};
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'dart:_http'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // ok (from dart:html)
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method testB(self::HttpRequest request) → dynamic {
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+  request.certificate; // error
+          ^^^^^^^^^^^" in request{<unresolved>}.certificate;
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+  request.response; // error
+          ^^^^^^^^" in request{<unresolved>}.response;
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // error
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method main() → void {
+  self::expect(false, #C1);
+  self::expect(true, #C1);
+  self::expect(false, #C1);
+}
+static method expect(dynamic expected, dynamic actual) → dynamic {
+  if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual))
+    throw "Expected ${expected}, actual ${actual}";
+}
+
+constants  {
+  #C1 = false
+}

pkg/front_end/testcases/dart2js/conditional_import.dart.strong.transformed.expect

@@ -0,0 +1,84 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'dart:_http'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // ok (from dart:html)
+//           ^^^^^^^^^^
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+//   request.certificate; // error
+//           ^^^^^^^^^^^
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+//   request.response; // error
+//           ^^^^^^^^
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // error
+//           ^^^^^^^^^^
+//
+import self as self;
+import "dart:core" as core;
+import "dart:_http" as _ht;
+import "dart:io" as io;
+
+import "dart:io" as a;
+import "org-dartlang-testcase:///conditional_import.dart" as b;
+
+class HttpRequest extends core::Object {
+  synthetic constructor •() → self::HttpRequest
+    : super core::Object::•()
+    ;
+  static method _#new#tearOff() → self::HttpRequest
+    return new self::HttpRequest::•();
+}
+static method testA(_ht::HttpRequest request) → dynamic {
+  request.{_ht::HttpRequest::certificate}{io::X509Certificate?};
+  request.{_ht::HttpRequest::response}{_ht::HttpResponse};
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'dart:_http'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // ok (from dart:html)
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method testB(self::HttpRequest request) → dynamic {
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+  request.certificate; // error
+          ^^^^^^^^^^^" in request{<unresolved>}.certificate;
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+  request.response; // error
+          ^^^^^^^^" in request{<unresolved>}.response;
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // error
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method main() → void {
+  self::expect(false, #C1);
+  self::expect(true, #C1);
+  self::expect(false, #C1);
+}
+static method expect(dynamic expected, dynamic actual) → dynamic {
+  if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual))
+    throw "Expected ${expected}, actual ${actual}";
+}
+
+constants  {
+  #C1 = false
+}

pkg/front_end/testcases/dart2js/conditional_import.dart.textual_outline.expect

@@ -0,0 +1,11 @@
+import "conditional_import.dart"
+    if (dart.library.io) "dart:io"
+    if (dart.library.html) "dart:html" as a;
+import "conditional_import.dart" if (dart.library.foo) "dart:foo" as b;
+
+class HttpRequest {}
+
+testA(a.HttpRequest request) {}
+testB(b.HttpRequest request) {}
+void main() {}
+expect(expected, actual) {}

pkg/front_end/testcases/dart2js/conditional_import.dart.textual_outline_modelled.expect

@@ -0,0 +1,11 @@
+import "conditional_import.dart" if (dart.library.foo) "dart:foo" as b;
+import "conditional_import.dart"
+    if (dart.library.io) "dart:io"
+    if (dart.library.html) "dart:html" as a;
+
+class HttpRequest {}
+
+expect(expected, actual) {}
+testA(a.HttpRequest request) {}
+testB(b.HttpRequest request) {}
+void main() {}

pkg/front_end/testcases/dart2js/conditional_import.dart.weak.expect

@@ -0,0 +1,84 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'dart:_http'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // ok (from dart:html)
+//           ^^^^^^^^^^
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+//   request.certificate; // error
+//           ^^^^^^^^^^^
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+//   request.response; // error
+//           ^^^^^^^^
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // error
+//           ^^^^^^^^^^
+//
+import self as self;
+import "dart:core" as core;
+import "dart:_http" as _ht;
+import "dart:io" as io;
+
+import "dart:io" as a;
+import "org-dartlang-testcase:///conditional_import.dart" as b;
+
+class HttpRequest extends core::Object {
+  synthetic constructor •() → self::HttpRequest
+    : super core::Object::•()
+    ;
+  static method _#new#tearOff() → self::HttpRequest
+    return new self::HttpRequest::•();
+}
+static method testA(_ht::HttpRequest request) → dynamic {
+  request.{_ht::HttpRequest::certificate}{io::X509Certificate?};
+  request.{_ht::HttpRequest::response}{_ht::HttpResponse};
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'dart:_http'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // ok (from dart:html)
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method testB(self::HttpRequest request) → dynamic {
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+  request.certificate; // error
+          ^^^^^^^^^^^" in request{<unresolved>}.certificate;
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+  request.response; // error
+          ^^^^^^^^" in request{<unresolved>}.response;
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // error
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method main() → void {
+  self::expect(false, #C1);
+  self::expect(true, #C1);
+  self::expect(false, #C1);
+}
+static method expect(dynamic expected, dynamic actual) → dynamic {
+  if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual))
+    throw "Expected ${expected}, actual ${actual}";
+}
+
+constants  {
+  #C1 = false
+}

pkg/front_end/testcases/dart2js/conditional_import.dart.weak.outline.expect

@@ -0,0 +1,22 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+import "dart:_http" as _ht;
+
+import "dart:io" as a;
+import "org-dartlang-testcase:///conditional_import.dart" as b;
+
+class HttpRequest extends core::Object {
+  synthetic constructor •() → self::HttpRequest
+    ;
+  static method _#new#tearOff() → self::HttpRequest
+    return new self::HttpRequest::•();
+}
+static method testA(_ht::HttpRequest request) → dynamic
+  ;
+static method testB(self::HttpRequest request) → dynamic
+  ;
+static method main() → void
+  ;
+static method expect(dynamic expected, dynamic actual) → dynamic
+  ;

pkg/front_end/testcases/dart2js/conditional_import.dart.weak.transformed.expect

@@ -0,0 +1,84 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'dart:_http'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // ok (from dart:html)
+//           ^^^^^^^^^^
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+//   request.certificate; // error
+//           ^^^^^^^^^^^
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+//   request.response; // error
+//           ^^^^^^^^
+//
+// pkg/front_end/testcases/dart2js/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // error
+//           ^^^^^^^^^^
+//
+import self as self;
+import "dart:core" as core;
+import "dart:_http" as _ht;
+import "dart:io" as io;
+
+import "dart:io" as a;
+import "org-dartlang-testcase:///conditional_import.dart" as b;
+
+class HttpRequest extends core::Object {
+  synthetic constructor •() → self::HttpRequest
+    : super core::Object::•()
+    ;
+  static method _#new#tearOff() → self::HttpRequest
+    return new self::HttpRequest::•();
+}
+static method testA(_ht::HttpRequest request) → dynamic {
+  request.{_ht::HttpRequest::certificate}{io::X509Certificate?};
+  request.{_ht::HttpRequest::response}{_ht::HttpResponse};
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'dart:_http'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // ok (from dart:html)
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method testB(self::HttpRequest request) → dynamic {
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+  request.certificate; // error
+          ^^^^^^^^^^^" in request{<unresolved>}.certificate;
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+  request.response; // error
+          ^^^^^^^^" in request{<unresolved>}.response;
+  invalid-expression "pkg/front_end/testcases/dart2js/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dart2js/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // error
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method main() → void {
+  self::expect(false, #C1);
+  self::expect(true, #C1);
+  self::expect(false, #C1);
+}
+static method expect(dynamic expected, dynamic actual) → dynamic {
+  if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual))
+    throw "Expected ${expected}, actual ${actual}";
+}
+
+constants  {
+  #C1 = false
+}

pkg/front_end/testcases/dartdevc/conditional_import.dart

@@ -0,0 +1,37 @@
+// Copyright (c) 2021, 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.
+
+// All three libraries have an HttpRequest class.
+import "conditional_import.dart"
+    if (dart.library.io) "dart:io"
+    if (dart.library.html) "dart:html" as a;
+
+// All three libraries have an HttpRequest class.
+import "conditional_import.dart" if (dart.library.foo) "dart:foo" as b;
+
+class HttpRequest {}
+
+testA(a.HttpRequest request) {
+  request.certificate; // error (from dart:io)
+  request.response; // ok (from dart:io and dart:html)
+  request.readyState; // ok (from dart:html)
+  request.hashCode; // ok
+}
+
+testB(b.HttpRequest request) {
+  request.certificate; // error
+  request.response; // error
+  request.readyState; // error
+  request.hashCode; // ok
+}
+
+void main() {
+  expect(false, const bool.fromEnvironment("dart.library.io"));
+  expect(true, const bool.fromEnvironment("dart.library.html"));
+  expect(false, const bool.fromEnvironment("dart.library.foo"));
+}
+
+expect(expected, actual) {
+  if (expected != actual) throw 'Expected $expected, actual $actual';
+}

pkg/front_end/testcases/dartdevc/conditional_import.dart.strong.expect

@@ -0,0 +1,84 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'dart:_http'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // ok (from dart:html)
+//           ^^^^^^^^^^
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+//   request.certificate; // error
+//           ^^^^^^^^^^^
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+//   request.response; // error
+//           ^^^^^^^^
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // error
+//           ^^^^^^^^^^
+//
+import self as self;
+import "dart:core" as core;
+import "dart:_http" as _ht;
+import "dart:io" as io;
+
+import "dart:io" as a;
+import "org-dartlang-testcase:///conditional_import.dart" as b;
+
+class HttpRequest extends core::Object {
+  synthetic constructor •() → self::HttpRequest
+    : super core::Object::•()
+    ;
+  static method _#new#tearOff() → self::HttpRequest
+    return new self::HttpRequest::•();
+}
+static method testA(_ht::HttpRequest request) → dynamic {
+  request.{_ht::HttpRequest::certificate}{io::X509Certificate?};
+  request.{_ht::HttpRequest::response}{_ht::HttpResponse};
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'dart:_http'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // ok (from dart:html)
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method testB(self::HttpRequest request) → dynamic {
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+  request.certificate; // error
+          ^^^^^^^^^^^" in request{<unresolved>}.certificate;
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+  request.response; // error
+          ^^^^^^^^" in request{<unresolved>}.response;
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // error
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method main() → void {
+  self::expect(false, #C1);
+  self::expect(true, #C1);
+  self::expect(false, #C1);
+}
+static method expect(dynamic expected, dynamic actual) → dynamic {
+  if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual))
+    throw "Expected ${expected}, actual ${actual}";
+}
+
+constants  {
+  #C1 = false
+}

pkg/front_end/testcases/dartdevc/conditional_import.dart.strong.transformed.expect

@@ -0,0 +1,84 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'dart:_http'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // ok (from dart:html)
+//           ^^^^^^^^^^
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+//   request.certificate; // error
+//           ^^^^^^^^^^^
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+//   request.response; // error
+//           ^^^^^^^^
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // error
+//           ^^^^^^^^^^
+//
+import self as self;
+import "dart:core" as core;
+import "dart:_http" as _ht;
+import "dart:io" as io;
+
+import "dart:io" as a;
+import "org-dartlang-testcase:///conditional_import.dart" as b;
+
+class HttpRequest extends core::Object {
+  synthetic constructor •() → self::HttpRequest
+    : super core::Object::•()
+    ;
+  static method _#new#tearOff() → self::HttpRequest
+    return new self::HttpRequest::•();
+}
+static method testA(_ht::HttpRequest request) → dynamic {
+  request.{_ht::HttpRequest::certificate}{io::X509Certificate?};
+  request.{_ht::HttpRequest::response}{_ht::HttpResponse};
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'dart:_http'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // ok (from dart:html)
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method testB(self::HttpRequest request) → dynamic {
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+  request.certificate; // error
+          ^^^^^^^^^^^" in request{<unresolved>}.certificate;
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+  request.response; // error
+          ^^^^^^^^" in request{<unresolved>}.response;
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // error
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method main() → void {
+  self::expect(false, #C1);
+  self::expect(true, #C1);
+  self::expect(false, #C1);
+}
+static method expect(dynamic expected, dynamic actual) → dynamic {
+  if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual))
+    throw "Expected ${expected}, actual ${actual}";
+}
+
+constants  {
+  #C1 = false
+}

pkg/front_end/testcases/dartdevc/conditional_import.dart.textual_outline.expect

@@ -0,0 +1,11 @@
+import "conditional_import.dart"
+    if (dart.library.io) "dart:io"
+    if (dart.library.html) "dart:html" as a;
+import "conditional_import.dart" if (dart.library.foo) "dart:foo" as b;
+
+class HttpRequest {}
+
+testA(a.HttpRequest request) {}
+testB(b.HttpRequest request) {}
+void main() {}
+expect(expected, actual) {}

pkg/front_end/testcases/dartdevc/conditional_import.dart.textual_outline_modelled.expect

@@ -0,0 +1,11 @@
+import "conditional_import.dart" if (dart.library.foo) "dart:foo" as b;
+import "conditional_import.dart"
+    if (dart.library.io) "dart:io"
+    if (dart.library.html) "dart:html" as a;
+
+class HttpRequest {}
+
+expect(expected, actual) {}
+testA(a.HttpRequest request) {}
+testB(b.HttpRequest request) {}
+void main() {}

pkg/front_end/testcases/dartdevc/conditional_import.dart.weak.expect

@@ -0,0 +1,84 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'dart:_http'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // ok (from dart:html)
+//           ^^^^^^^^^^
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+//   request.certificate; // error
+//           ^^^^^^^^^^^
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+//   request.response; // error
+//           ^^^^^^^^
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // error
+//           ^^^^^^^^^^
+//
+import self as self;
+import "dart:core" as core;
+import "dart:_http" as _ht;
+import "dart:io" as io;
+
+import "dart:io" as a;
+import "org-dartlang-testcase:///conditional_import.dart" as b;
+
+class HttpRequest extends core::Object {
+  synthetic constructor •() → self::HttpRequest
+    : super core::Object::•()
+    ;
+  static method _#new#tearOff() → self::HttpRequest
+    return new self::HttpRequest::•();
+}
+static method testA(_ht::HttpRequest request) → dynamic {
+  request.{_ht::HttpRequest::certificate}{io::X509Certificate?};
+  request.{_ht::HttpRequest::response}{_ht::HttpResponse};
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'dart:_http'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // ok (from dart:html)
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method testB(self::HttpRequest request) → dynamic {
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+  request.certificate; // error
+          ^^^^^^^^^^^" in request{<unresolved>}.certificate;
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+  request.response; // error
+          ^^^^^^^^" in request{<unresolved>}.response;
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // error
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method main() → void {
+  self::expect(false, #C1);
+  self::expect(true, #C1);
+  self::expect(false, #C1);
+}
+static method expect(dynamic expected, dynamic actual) → dynamic {
+  if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual))
+    throw "Expected ${expected}, actual ${actual}";
+}
+
+constants  {
+  #C1 = false
+}

pkg/front_end/testcases/dartdevc/conditional_import.dart.weak.outline.expect

@@ -0,0 +1,22 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+import "dart:_http" as _ht;
+
+import "dart:io" as a;
+import "org-dartlang-testcase:///conditional_import.dart" as b;
+
+class HttpRequest extends core::Object {
+  synthetic constructor •() → self::HttpRequest
+    ;
+  static method _#new#tearOff() → self::HttpRequest
+    return new self::HttpRequest::•();
+}
+static method testA(_ht::HttpRequest request) → dynamic
+  ;
+static method testB(self::HttpRequest request) → dynamic
+  ;
+static method main() → void
+  ;
+static method expect(dynamic expected, dynamic actual) → dynamic
+  ;

pkg/front_end/testcases/dartdevc/conditional_import.dart.weak.transformed.expect

@@ -0,0 +1,84 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'dart:_http'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // ok (from dart:html)
+//           ^^^^^^^^^^
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+//   request.certificate; // error
+//           ^^^^^^^^^^^
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+//   request.response; // error
+//           ^^^^^^^^
+//
+// pkg/front_end/testcases/dartdevc/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // error
+//           ^^^^^^^^^^
+//
+import self as self;
+import "dart:core" as core;
+import "dart:_http" as _ht;
+import "dart:io" as io;
+
+import "dart:io" as a;
+import "org-dartlang-testcase:///conditional_import.dart" as b;
+
+class HttpRequest extends core::Object {
+  synthetic constructor •() → self::HttpRequest
+    : super core::Object::•()
+    ;
+  static method _#new#tearOff() → self::HttpRequest
+    return new self::HttpRequest::•();
+}
+static method testA(_ht::HttpRequest request) → dynamic {
+  request.{_ht::HttpRequest::certificate}{io::X509Certificate?};
+  request.{_ht::HttpRequest::response}{_ht::HttpResponse};
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'dart:_http'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // ok (from dart:html)
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method testB(self::HttpRequest request) → dynamic {
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+  request.certificate; // error
+          ^^^^^^^^^^^" in request{<unresolved>}.certificate;
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+  request.response; // error
+          ^^^^^^^^" in request{<unresolved>}.response;
+  invalid-expression "pkg/front_end/testcases/dartdevc/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/dartdevc/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // error
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method main() → void {
+  self::expect(false, #C1);
+  self::expect(true, #C1);
+  self::expect(false, #C1);
+}
+static method expect(dynamic expected, dynamic actual) → dynamic {
+  if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual))
+    throw "Expected ${expected}, actual ${actual}";
+}
+
+constants  {
+  #C1 = false
+}

pkg/front_end/testcases/general/conditional_import.dart

@@ -0,0 +1,37 @@
+// Copyright (c) 2021, 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.
+
+// All three libraries have an HttpRequest class.
+import "conditional_import.dart"
+    if (dart.library.io) "dart:io"
+    if (dart.library.html) "dart:html" as a;
+
+// All three libraries have an HttpRequest class.
+import "conditional_import.dart" if (dart.library.foo) "dart:foo" as b;
+
+class HttpRequest {}
+
+testA(a.HttpRequest request) {
+  request.certificate; // ok (from dart:io)
+  request.response; // ok (from dart:io and dart:html)
+  request.readyState; // error (from dart:html)
+  request.hashCode; // ok
+}
+
+testB(b.HttpRequest request) {
+  request.certificate; // error
+  request.response; // error
+  request.readyState; // error
+  request.hashCode; // ok
+}
+
+void main() {
+  expect(true, const bool.fromEnvironment("dart.library.io"));
+  expect(false, const bool.fromEnvironment("dart.library.html"));
+  expect(false, const bool.fromEnvironment("dart.library.foo"));
+}
+
+expect(expected, actual) {
+  if (expected != actual) throw 'Expected $expected, actual $actual';
+}

pkg/front_end/testcases/general/conditional_import.dart.textual_outline.expect

@@ -0,0 +1,11 @@
+import "conditional_import.dart"
+    if (dart.library.io) "dart:io"
+    if (dart.library.html) "dart:html" as a;
+import "conditional_import.dart" if (dart.library.foo) "dart:foo" as b;
+
+class HttpRequest {}
+
+testA(a.HttpRequest request) {}
+testB(b.HttpRequest request) {}
+void main() {}
+expect(expected, actual) {}

pkg/front_end/testcases/general/conditional_import.dart.textual_outline_modelled.expect

@@ -0,0 +1,11 @@
+import "conditional_import.dart" if (dart.library.foo) "dart:foo" as b;
+import "conditional_import.dart"
+    if (dart.library.io) "dart:io"
+    if (dart.library.html) "dart:html" as a;
+
+class HttpRequest {}
+
+expect(expected, actual) {}
+testA(a.HttpRequest request) {}
+testB(b.HttpRequest request) {}
+void main() {}

pkg/front_end/testcases/general/conditional_import.dart.weak.expect

@@ -0,0 +1,82 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'dart:_http'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // error (from dart:html)
+//           ^^^^^^^^^^
+//
+// pkg/front_end/testcases/general/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/general/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+//   request.certificate; // error
+//           ^^^^^^^^^^^
+//
+// pkg/front_end/testcases/general/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/general/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+//   request.response; // error
+//           ^^^^^^^^
+//
+// pkg/front_end/testcases/general/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/general/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // error
+//           ^^^^^^^^^^
+//
+import self as self;
+import "dart:core" as core;
+import "dart:_http" as _ht;
+import "dart:io" as io;
+
+import "dart:io" as a;
+import "org-dartlang-testcase:///conditional_import.dart" as b;
+
+class HttpRequest extends core::Object {
+  synthetic constructor •() → self::HttpRequest
+    : super core::Object::•()
+    ;
+}
+static method testA(_ht::HttpRequest request) → dynamic {
+  request.{_ht::HttpRequest::certificate}{io::X509Certificate?};
+  request.{_ht::HttpRequest::response}{_ht::HttpResponse};
+  invalid-expression "pkg/front_end/testcases/general/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'dart:_http'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // error (from dart:html)
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method testB(self::HttpRequest request) → dynamic {
+  invalid-expression "pkg/front_end/testcases/general/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/general/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+  request.certificate; // error
+          ^^^^^^^^^^^" in request{<unresolved>}.certificate;
+  invalid-expression "pkg/front_end/testcases/general/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/general/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+  request.response; // error
+          ^^^^^^^^" in request{<unresolved>}.response;
+  invalid-expression "pkg/front_end/testcases/general/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/general/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // error
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method main() → void {
+  self::expect(true, #C1);
+  self::expect(false, #C1);
+  self::expect(false, #C1);
+}
+static method expect(dynamic expected, dynamic actual) → dynamic {
+  if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual))
+    throw "Expected ${expected}, actual ${actual}";
+}
+
+constants  {
+  #C1 = false
+}

pkg/front_end/testcases/general/conditional_import.dart.weak.outline.expect

@@ -0,0 +1,20 @@
+library /*isNonNullableByDefault*/;
+import self as self;
+import "dart:core" as core;
+import "dart:_http" as _ht;
+
+import "dart:io" as a;
+import "org-dartlang-testcase:///conditional_import.dart" as b;
+
+class HttpRequest extends core::Object {
+  synthetic constructor •() → self::HttpRequest
+    ;
+}
+static method testA(_ht::HttpRequest request) → dynamic
+  ;
+static method testB(self::HttpRequest request) → dynamic
+  ;
+static method main() → void
+  ;
+static method expect(dynamic expected, dynamic actual) → dynamic
+  ;

pkg/front_end/testcases/general/conditional_import.dart.weak.transformed.expect

@@ -0,0 +1,82 @@
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/general/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'dart:_http'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // error (from dart:html)
+//           ^^^^^^^^^^
+//
+// pkg/front_end/testcases/general/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/general/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+//   request.certificate; // error
+//           ^^^^^^^^^^^
+//
+// pkg/front_end/testcases/general/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/general/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+//   request.response; // error
+//           ^^^^^^^^
+//
+// pkg/front_end/testcases/general/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+//  - 'HttpRequest' is from 'pkg/front_end/testcases/general/conditional_import.dart'.
+// Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+//   request.readyState; // error
+//           ^^^^^^^^^^
+//
+import self as self;
+import "dart:core" as core;
+import "dart:_http" as _ht;
+import "dart:io" as io;
+
+import "dart:io" as a;
+import "org-dartlang-testcase:///conditional_import.dart" as b;
+
+class HttpRequest extends core::Object {
+  synthetic constructor •() → self::HttpRequest
+    : super core::Object::•()
+    ;
+}
+static method testA(_ht::HttpRequest request) → dynamic {
+  request.{_ht::HttpRequest::certificate}{io::X509Certificate?};
+  request.{_ht::HttpRequest::response}{_ht::HttpResponse};
+  invalid-expression "pkg/front_end/testcases/general/conditional_import.dart:18:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'dart:_http'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // error (from dart:html)
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method testB(self::HttpRequest request) → dynamic {
+  invalid-expression "pkg/front_end/testcases/general/conditional_import.dart:23:11: Error: The getter 'certificate' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/general/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'certificate'.
+  request.certificate; // error
+          ^^^^^^^^^^^" in request{<unresolved>}.certificate;
+  invalid-expression "pkg/front_end/testcases/general/conditional_import.dart:24:11: Error: The getter 'response' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/general/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'response'.
+  request.response; // error
+          ^^^^^^^^" in request{<unresolved>}.response;
+  invalid-expression "pkg/front_end/testcases/general/conditional_import.dart:25:11: Error: The getter 'readyState' isn't defined for the class 'HttpRequest'.
+ - 'HttpRequest' is from 'pkg/front_end/testcases/general/conditional_import.dart'.
+Try correcting the name to the name of an existing getter, or defining a getter or field named 'readyState'.
+  request.readyState; // error
+          ^^^^^^^^^^" in request{<unresolved>}.readyState;
+  request.{core::Object::hashCode}{core::int};
+}
+static method main() → void {
+  self::expect(true, #C1);
+  self::expect(false, #C1);
+  self::expect(false, #C1);
+}
+static method expect(dynamic expected, dynamic actual) → dynamic {
+  if(!(expected =={core::Object::==}{(core::Object) → core::bool} actual))
+    throw "Expected ${expected}, actual ${actual}";
+}
+
+constants  {
+  #C1 = false
+}

pkg/front_end/testcases/text_serialization.status

@@ -33,6 +33,7 @@ general/bug30695: TypeCheckError
 general/bug31124: RuntimeError
 general/call: RuntimeError
 general/cascade: RuntimeError
+general/conditional_import: RuntimeError # Issue 47814
 general/constructor_initializer_invalid: RuntimeError
 general/covariant_field: TypeCheckError
 general/covariant_generic: RuntimeError

pkg/front_end/testcases/weak.status

@@ -46,6 +46,7 @@ general/bug30695: TypeCheckError
 general/bug31124: RuntimeError # Test has no main method (and we shouldn't add one).
 general/call: RuntimeError
 general/cascade: RuntimeError
+general/conditional_import: RuntimeError # Issue 47814
 general/constructor_initializer_invalid: RuntimeError # Fails execution after recovery
 general/covariant_field: TypeCheckError
 general/covariant_generic: RuntimeError