Fixes to make Travis Green (#17)

* Remove unused import
* Only analyze lib and test dirs
  - work-around for https://github.com/dart-lang/sdk/issues/26212
* enable a few more lints
* remove unused field

.travis.yml

@@ -16,8 +16,10 @@ matrix:
   include:
   - dart: stable
     dart_task: dartfmt
+  # Wish we could exclude `examples` in `analysis_options.yaml` but it seems
+  # blocked by https://github.com/dart-lang/sdk/issues/26212
   - dart: dev
-    dart_task: dartanalyzer
+    dart_task: dartanalyzer lib test
 
 # Only building master means that we don't run two builds for each pull request.
 branches:

analysis_options.yaml

@@ -6,13 +6,16 @@ analyzer:
 # Lint rules and documentation, see http://dart-lang.github.io/linter/lints
 linter:
   rules:
+    - avoid_init_to_null
     - cancel_subscriptions
     - close_sinks
+    - directives_ordering
     - hash_and_equals
     - iterable_contains_unrelated_type
     - list_remove_unrelated_type
     - prefer_final_fields
     - prefer_final_locals
+    - prefer_is_not_empty
     - test_types_in_equals
     - unrelated_type_equality_checks
     - valid_regexps

examples/route_guide/lib/src/client.dart

@@ -7,9 +7,9 @@ import 'dart:math' show Random;
 
 import 'package:grpc/grpc.dart';
 
+import 'common.dart';
 import 'generated/route_guide.pb.dart';
 import 'generated/route_guide.pbgrpc.dart';
-import 'common.dart';
 
 class Client {
   ClientChannel channel;

examples/route_guide/lib/src/server.dart

@@ -3,7 +3,6 @@
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:io';
 import 'dart:math' show PI, atan2, cos, max, min, sin, sqrt;
 
 import 'package:grpc/grpc.dart' as grpc;
@@ -66,7 +65,7 @@ class RouteGuideService extends RouteGuideServiceBase {
     int pointCount = 0;
     int featureCount = 0;
     double distance = 0.0;
-    Point previous = null;
+    Point previous;
     final timer = new Stopwatch();
 
     await for (var location in request) {

lib/src/client.dart

@@ -55,7 +55,6 @@ class ClientMethod<Q, R> {
 class ClientCall<Q, R> implements Response {
   static final _methodPost = new Header.ascii(':method', 'POST');
   static final _schemeHttp = new Header.ascii(':scheme', 'http');
-  static final _schemeHttps = new Header.ascii(':scheme', 'https');
   static final _contentTypeGrpc =
       new Header.ascii('content-type', 'application/grpc');
   static final _teTrailers = new Header.ascii('te', 'trailers');

lib/src/server.dart

@@ -5,8 +5,6 @@
 import 'dart:async';
 import 'dart:io';
 
-import 'package:meta/meta.dart';
-import 'package:http2/multiprotocol_server.dart';
 import 'package:http2/transport.dart';
 
 import 'streams.dart';