spawnHybridCode function
Spawns a VM isolate that runs the given dartCode
, which is loaded as the
contents of a Dart library.
This allows browser tests to spawn servers with which they can communicate to test client/server interactions. It can also be used by VM tests to easily spawn an isolate.
The dartCode
must define a top-level hybridMain()
function that takes a
StreamChannel
argument and, optionally, an Object
argument to which
message
will be passed. Note that message
must be JSON-encodable. For
example:
import "package:stream_channel/stream_channel.dart";
hybridMain(StreamChannel channel, Object message) {
// ...
}
Returns a StreamChannel that's connected to the channel passed to
hybridMain()
. Only JSON-encodable objects may be sent through this
channel. If the channel is closed, the hybrid isolate is killed. If the
isolate is killed, the channel's stream will emit a "done" event.
Any unhandled errors loading or running the hybrid isolate will be emitted
as errors over the channel's stream. Any calls to print()
in the hybrid
isolate will be printed as though they came from the test that created the
isolate.
Code in the hybrid isolate is not considered to be running in a test
context, so it can't access test functions like expect()
and
expectAsync()
.
By default, the hybrid isolate is automatically killed when the test
finishes running. If stayAlive
is true
, it won't be killed until the
entire test suite finishes running.
Note: If you use this API, be sure to add a dependency on the
**stream_channel
package, since you're using its API as well!
Implementation
StreamChannel spawnHybridCode(String dartCode,
{Object message, bool stayAlive = false}) {
var uri = Uri.dataFromString(dartCode,
encoding: utf8, mimeType: 'application/dart');
return _spawn(uri.toString(), message, stayAlive: stayAlive);
}