pkg/test: Resolve a number of analyzer warnings

lib/src/utils.dart

Index: lib/src/utils.dart
diff --git a/lib/src/utils.dart b/lib/src/utils.dart
index bc5a2701e9dbe16aff2b2c337f36061191cf9f71..19210f515dff55e034ef78b1932bd547ab0ad118 100644
--- a/lib/src/utils.dart
+++ b/lib/src/utils.dart
@@ -27,8 +27,9 @@ typedef AsyncFunction();
 /// A typedef for a zero-argument callback function.
 typedef void Callback();
 
-/// A converter that decodes bytes using UTF-8 and splits them on newlines.
-final lineSplitter = UTF8.decoder.fuse(const LineSplitter());
+/// Transforms the [source] stream of UTF8 bytes into a [Stream] of lines.
+Stream<String> transformUtf8ToLines(Stream<List<int>> source) =>
+    source.transform(UTF8.decoder).transform(const LineSplitter());

[nweiz, 2016/06/23 21:47:36]

You can make this an actual StreamTransformer using new StreamTransformer:
https://api.dartlang.org/stable/1.17.1/dart-async/StreamTransformer/StreamTra...

[kevmoo, 2016/06/23 21:57:08]

Yes, but is there an upside to doing so?

Also, I'm struggling to figure out an easy way to do it.

final StreamTransformer<List<int>, String> transformer = new StreamTransformer(
    (Stream<List<int>> stream, cancelOnError) => stream
            .transform(UTF8.decoder)
            .transform(const LineSplitter())
            .listen((s) {
          // now what?
        }));

[nweiz, 2016/06/23 22:02:56]

The API for using it is nicer and produces less churn.
You pass null to the listen callback and return its result.

[kevmoo, 2016/06/23 22:12:24]

Done.

 
 /// A regular expression to match the exception prefix that some exceptions'
 /// [Object.toString] values contain.