Initial backend for metrics in Observatory

tests/lib/profiler/metrics_test.dart

+// Copyright (c) 2014, 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:profiler';
+import 'package:expect/expect.dart';
+
+testGauge() {
+  var gauge = new Gauge('test', 'alpha bravo');
+  Expect.equals(0.0, gauge.value);
+  Expect.equals('test', gauge.name);
+  Expect.equals('alpha bravo', gauge.description);
+  Expect.equals(null, gauge.min);
+  Expect.equals(null, gauge.max);
+  gauge.value = 44.0;
+  Expect.equals(44.0, gauge.value);
+}
+
+testGaugeRange() {
+  var gauge = new Gauge.range('test', 'alpha bravo', 1.0, 2.0);
+  Expect.equals(0.0, gauge.value);
+  Expect.equals('test', gauge.name);
+  Expect.equals('alpha bravo', gauge.description);
+  Expect.equals(1.0, gauge.min);
+  Expect.equals(2.0, gauge.max);
+
+  Expect.throws(() {
+    // min > max.
+    gauge = new Gauge.range('test', 'alpha bravo', 2.0, 1.0);
+  });
+
+  Expect.throws(() {
+    // min == max.
+    gauge = new Gauge.range('test', 'alpha bravo', 1.0, 1.0);
+  });
+
+  Expect.throws(() {
+    // min == max.
+    gauge = new Gauge.range('test', 'alpha bravo', 1.0, 1.0);
+  });
+
+  Expect.throws(() {
+    // min is null
+    gauge = new Gauge.range('test', 'alpha bravo', null, 1.0);
+  });
+
+  Expect.throws(() {
+    // min is not a double
+    gauge = new Gauge.range('test', 'alpha bravo', 'string', 1.0);
+  });
+
+  Expect.throws(() {
+    // max is null
+    gauge = new Gauge.range('test', 'alpha bravo', 1.0, null);
+  });
+
+  Expect.throws(() {
+    // max is not a double
+    gauge = new Gauge.range('test', 'alpha bravo', 1.0, 4);
+  });
+
+  Expect.equals(0.0, gauge.value);
+  Expect.equals('test', gauge.name);
+  Expect.equals('alpha bravo', gauge.description);
+  Expect.equals(1.0, gauge.min);
+  Expect.equals(2.0, gauge.max);
+}
+
+testCounter() {
+  var counter = new Counter('test', 'alpha bravo');
+  Expect.equals(0.0, counter.value);
+  Expect.equals('test', counter.name);
+  Expect.equals('alpha bravo', counter.description);
+  counter.add(1.0);
+  Expect.equals(1.0, counter.value);
+}
+
+main() {
+  testGauge();
+  testGaugeRange();
+  testCounter();
+}