- Implement package map parameter when spawning isolate.

tests/isolate/package_map_test.dart

+// Copyright (c) 2015, 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.
+
+import 'dart:io';
+import 'dart:isolate';
+
+final NOT_HERE = "notHere";
+final NOT_HERE_URI = "file:///no/such/file/";
+
+class Foo {}
+
+void main([args, port]) {
+  if (port != null) {
+    testPackageRoot(port);
+    return;
+  }
+  var p = new RawReceivePort();
+  p.handler = (msg) {
+    p.close();
+    if (msg is! List) {
+      throw "Bad response from child isolate: $msg";
+    }
+    if (msg.length != 2) {
+      throw "Length should be 2: ${msg.length}\nmsg: $msg";
+    }

[Lasse Reichstein Nielsen, 2015/10/12 09:34:44]

Add a comment that you are not using the expect package because the second
isolate wouldn't be able to load it.

+    if (msg[0] != NOT_HERE) {
+      throw "Key should be $NOT_HERE: ${msg[0]}";
+    }
+    if (msg[1] != NOT_HERE_URI) {
+      throw "Value should be $NOT_HERE_URI: ${msg[1]}";
+    }
+  };
+  Isolate.spawnUri(Platform.script,
+                   [],
+                   p.sendPort,
+                   packages: {
+                     NOT_HERE: Uri.parse(NOT_HERE_URI)
+                   });
+}
+
+testPackageRoot(port) async {
+  var packageMap = await Isolate.packageMap;
+  var packageMapEntries = [];
+  if (packageMap is! Map) {
+    port.send("packageMap is not a Map: ${packageMap.runtimeType}");
+    return;
+  }
+  var ok = true;

[Lasse Reichstein Nielsen, 2015/10/12 09:34:44]

You don't actually need the ok variable - the first message sent on the
send-port will be the only message received, so sending on the port is will
effectively make everything that happens after that ignored.

It's probably fine as extra documentation.

[Ivan Posva, 2015/10/12 16:05:22]

I did not want to have an expectation where multiple errors would be reported.

+  packageMap.forEach((k, v) {
+    if (ok && (k is! String)) {
+      port.send("Key $k is not a String: ${k.runtimeType}");
+      ok = false;
+    }
+    packageMapEntries.add(k);
+    if (ok && (v is! Uri)) {
+      port.send("Value $v is not a Uri: ${v.runtimeType}");
+      ok = false;
+    }
+    packageMapEntries.add(v.toString());

[Lasse Reichstein Nielsen, 2015/10/12 09:34:44]

It's slightly surprising that you add the entries even if there is an error.
Maybe test first, add later? Ex:

  if (!ok) return;
  if (k is! String) {
    port.send(...);
    ok = false;
    return;
  }
  if (v is! Uri) {
    port.send(...);
    ok = false;
    return;
  }
  packageMapEntries.add(k);
  packageMapEntries.add("$v");
   

+  });
+  if (ok) {
+    port.send(packageMapEntries);
+  }
+}