Remove dependency on pkg/uuid

Use a home-rolled version

lib/src/http.dart

@@ -10,7 +10,6 @@ import 'dart:io';
 import 'package:http/http.dart' as http;
 import 'package:http_throttle/http_throttle.dart';
 import 'package:stack_trace/stack_trace.dart';
-import 'package:uuid/uuid.dart';
 
 import 'command_runner.dart';
 import 'io.dart';
@@ -31,7 +30,7 @@ final _CENSORED_FIELDS = const ['refresh_token', 'authorization'];
 final PUB_API_HEADERS = const {'Accept': 'application/vnd.pub.v2+json'};
 
 /// A unique ID to identify this particular invocation of pub.
-final _sessionId = new Uuid().v4() as String;
+final _sessionId = createUuid();
 
 /// An HTTP client that transforms 40* errors and socket exceptions into more
 /// user-friendly error messages.

lib/src/utils.dart

@@ -824,3 +824,26 @@ void dataError(String message) => throw new DataException(message);
 Iterable/*<T>*/ combineIterables/*<T>*/(
         Iterable/*<T>*/ iter1, Iterable/*<T>*/ iter2) =>
     iter1.toList()..addAll(iter2);
+
+/// Returns a UUID in v4 format as a `String`.
+///
+/// If [bytes] is provided, it must be length 16 and have values between `0` and
+/// `255` inclusive.
+///
+/// If [bytes] is not provided, it is generated using `Random.secure`.
+String createUuid([List<int> bytes]) {
+  var rnd = new math.Random.secure();
+
+  // See http://www.cryptosys.net/pki/uuid-rfc4122.html for notes
+  bytes ??= new List<int>.generate(16, (_) => rnd.nextInt(256));
+  bytes[6] = (bytes[6] & 0x0F) | 0x40;
+  bytes[8] = (bytes[8] & 0x3f) | 0x80;
+
+  var chars = bytes
+      .map((b) => b.toRadixString(16).padLeft(2, '0'))
+      .join()
+      .toUpperCase();
+
+  return '${chars.substring(0, 8)}-${chars.substring(8, 12)}-'
+      '${chars.substring(12, 16)}-${chars.substring(16, 20)}-${chars.substring(20, 32)}';
+}

pubspec.yaml

@@ -31,7 +31,6 @@ dependencies:
   stack_trace: "^1.0.0"
   stream_channel: "^1.4.0"
   string_scanner: "^1.0.0"
-  uuid: "^0.5.0"
   watcher: "^0.9.2"
   web_socket_channel: "^1.0.0"
   yaml: "^2.0.0"

test/utils_test.dart

@@ -102,4 +102,26 @@ b: {}"""));
       expect(niceDuration(new Duration(minutes: 1)), equals("1:00.0s"));
     });
   });
+
+  group('uuid', () {
+    var uuidRegexp = new RegExp("^[0-9A-F]{8}-[0-9A-F]{4}-4[0-9A-F]{3}-"
+        r"[8-9A-B][0-9A-F]{3}-[0-9A-F]{12}$");
+
+    test("min value is valid", () {
+      var uuid = createUuid(new List<int>.filled(16, 0));
+      expect(uuid, matches(uuidRegexp));
+      expect(uuid, "00000000-0000-4000-8000-000000000000");
+    });
+    test("max value is valid", () {
+      var uuid = createUuid(new List<int>.filled(16, 255));
+      expect(uuid, matches(uuidRegexp));
+      expect(uuid, "FFFFFFFF-FFFF-4FFF-BFFF-FFFFFFFFFFFF");
+    });
+    test("random values are valid", () {
+      for (var i = 0; i < 100; i++) {
+        var uuid = createUuid();
+        expect(uuid, matches(uuidRegexp));
+      }
+    });
+  });
 }