Fixed assert causing crash when attempting to load a library from an invalid path.

tests/language/vm/regress_27201_test.dart

+/*
+ * Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file

[zra, 2016/11/29 21:24:35]

2016

[bkonyi, 2016/11/29 21:43:17]

Done.

+ * 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.
+ */
+/**

[zra, 2016/11/29 21:24:35]

We probably don't need to copy this comment from the co19 test.

[bkonyi, 2016/11/29 21:43:17]

Done.

+ * @assertion The current library is the library currently being compiled. The
+ * import modifies the import namespace of the current library in a manner that
+ * is determined by the imported library and by the optional elements of the
+ * import.
+ * . . .
+ * Let I be an import directive that refers to a URI via the string s1.
+ * Evaluation of I proceeds as follows:
+ *
+ * If I is a deferred import, no evaluation takes place. Instead, a mapping of
+ * the name of the prefix, p to a deferred prefix object is added to the scope
+ * of the current library L. The deferred prefix object has the following
+ * methods:
+ * • loadLibrary. This method returns a future f. When called, the method
+ *   causes an immediate import I to be executed at some future time, where
+ *   I is is derived from I by eliding the word deferred and adding a hide
+ *   loadLibrary combinator clause. When I executes without error, f completes
+ *   successfully. If I executes without error, we say that the call to
+ *   loadLibrary has succeeded, otherwise we say the call has failed.
+ * • For every top level function f named id in the imported library B, a
+ *   corresponding method named id with the same signature as f. Calling
+ *   the method results in a runtime error.
+ * • For every top level getter g named id in B, a corresponding getter named
+ *   id with the same signature as g. Calling the method results in a runtime
+ *    error.
+ * • For every top level setter s named id in B, a corresponding setter named
+ *   id with the same signature as s. Calling the method results in a runtime
+ *   error.
+ * • For every type T named id in B, a corresponding getter named id with
+ *   return type Type. Calling the method results in a runtime error.
+ * . . .
+ * After a call succeeds, the name p is mapped to a non-deferred prefix object
+ * as described below. In addition, the prefix object also supports the
+ * loadLibrary method, and so it is possible to call loadLibrary again. If
+ * a call fails, nothing happens, and one again has the option to call
+ * loadLibrary again. Whether a repeated call to loadLibrary succeeds will
+ * vary as described below.
+ * The effect of a repeated call to p.loadLibrary is as follows:
+ * • If another call to p.loadLibrary has already succeeded, the repeated call
+ *   also succeeds. Otherwise,
+ * • If another call to to p.loadLibrary has failed:
+ *   – If the failure is due to a compilation error, the repeated call fails
+ *     for the same reason.
+ *   – If the failure is due to other causes, the repeated call behaves as if
+ *     no previous call had been made.
+ * In other words, one can retry a deferred load after a network failure or
+ * because a file is absent, but once one finds some content and loads it, one
+ * can no longer reload.
+ *
+ * @description Checks that if a library is load successfully, prefix is
+ * mapped to a non-deferred prefix object, and top-level declarations from
+ * the imported library became accessed in the current library with specified
+ * prefix. If a call loadLibrary fails nothing happens, and one again has the
+ * option to call loadLibrary again. Also checks to see that an attempt to
+ * load a library from a bad path throws a sane exception.
+ * @author ngl@unipro.ru
+ */
+import "dart:async";
+import "../../co19/src/Utils/expect.dart";

[zra, 2016/11/29 21:24:35]

Let's not have a dependence on co19 here. Use:

import "package:expect/expect.dart"

instead.

[bkonyi, 2016/11/29 21:43:17]

Done.

+import "regress_27201_lib.dart" deferred as p;
+import "regress_27201_bad_lib_path.dart" deferred as q;
+
+test_loaded() {
+  try {
+    p.someFunc();
+  } catch (e) {
+    Expect.fail("Should not be here");
+  }
+  try {
+    p.someGetter;
+  } catch (e) {
+    Expect.fail("Should not be here");
+  }
+  try {
+    p.someSetter = 1;
+  } catch (e) {
+    Expect.fail("Should not be here");
+  }
+  try {
+    p.Func;
+  } catch (e) {
+    Expect.fail("Should not be here");
+  }
+  try {
+    Expect.isTrue(p.loadLibrary() is Future);
+  } catch (e) {
+    Expect.fail("Should not be here");
+  }
+}
+
+
+main() async {

[zra, 2016/11/29 21:24:35]

There is no await, so async is not needed.

[bkonyi, 2016/11/29 21:43:17]

Done.

+  p.loadLibrary().then((v) {
+    test_loaded();
+  },
+  onError: (e) {
+    Expect.fail("Should have loaded library!");
+  });
+
+  // Ensure bad library import is handled correctly

[zra, 2016/11/29 21:24:35]

Please end comments with a '.'

[bkonyi, 2016/11/29 21:43:17]

Done.

+  q.loadLibrary().then((v) {
+    Expect.fail("Should have failed");
+  },
+  onError: (e) {
+    Expect.throws(() => q.x);
+  });
+}
+