fix deprecated pkg/test function usage

diff --git a/pubspec.yaml b/pubspec.yaml
index daeedc7..4c2325f 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml

@@ -24,7 +24,7 @@
   benchmark_harness: '>=1.0.0 <2.0.0'
   browser: any
   chart: '>=1.0.8 <2.0.0'
-  test: '^0.12.0'
+  test: '^0.12.18+1'
   stack_trace: '>=0.9.1 <2.0.0'
 environment:
   sdk: ">=1.9.0 <2.0.0"

diff --git a/test/observe_test.dart b/test/observe_test.dart
index 97a92e2..ba0bf9d 100644
--- a/test/observe_test.dart
+++ b/test/observe_test.dart

@@ -93,7 +93,7 @@
   });
 
   test('handle future result', () {
-    var callback = expectAsync(() {});
+    var callback = expectAsync0(() {});
     return new Future(callback);
   });
 
@@ -117,7 +117,7 @@
     var t = createModel(123);
     int called = 0;
 
-    subs.add(t.changes.listen(expectAsync((records) {
+    subs.add(t.changes.listen(expectAsync1((records) {
       called++;
       expectPropertyChanges(records, watch ? 1 : 2);
     })));
@@ -131,7 +131,7 @@
     var t = createModel(123);
     int called = 0;
 
-    subs.add(t.changes.listen(expectAsync((records) {
+    subs.add(t.changes.listen(expectAsync1((records) {
       called++;
       expectPropertyChanges(records, 1);
       if (called == 1) {
@@ -150,8 +150,8 @@
       expectPropertyChanges(records, watch ? 1 : 2);
     }
 
-    subs.add(t.changes.listen(expectAsync(verifyRecords)));
-    subs.add(t.changes.listen(expectAsync(verifyRecords)));
+    subs.add(t.changes.listen(expectAsync1(verifyRecords)));
+    subs.add(t.changes.listen(expectAsync1(verifyRecords)));
 
     t.value = 41;
     t.value = 42;
@@ -185,7 +185,7 @@
   test('cancel listening', () {
     var t = createModel(123);
     var sub;
-    sub = t.changes.listen(expectAsync((records) {
+    sub = t.changes.listen(expectAsync1((records) {
       expectPropertyChanges(records, 1);
       sub.cancel();
       t.value = 777;
@@ -197,12 +197,12 @@
   test('cancel and reobserve', () {
     var t = createModel(123);
     var sub;
-    sub = t.changes.listen(expectAsync((records) {
+    sub = t.changes.listen(expectAsync1((records) {
       expectPropertyChanges(records, 1);
       sub.cancel();
 
       scheduleMicrotask(() {
-        subs.add(t.changes.listen(expectAsync((records) {
+        subs.add(t.changes.listen(expectAsync1((records) {
           expectPropertyChanges(records, 1);
         })));
         t.value = 777;

diff --git a/test/path_observer_test.dart b/test/path_observer_test.dart
index bc7731a..db8037d 100644
--- a/test/path_observer_test.dart
+++ b/test/path_observer_test.dart

@@ -101,7 +101,8 @@
 
     test('objects with toString are not supported', () {
       // Dart note: this was intentionally not ported. See path_observer.dart.
-      expect(() => new PropertyPath([new Foo('a'), new Foo('b')]), throws);
+      expect(() => new PropertyPath([new Foo('a'), new Foo('b')]),
+          throwsArgumentError);
     });
 
     test('invalid path returns null value', () {
@@ -293,7 +294,7 @@
   test('Path Value With Indices', () {
     var model = toObservable([]);
     var path = new PathObserver(model, '[0]');
-    path.open(expectAsync((x) {
+    path.open(expectAsync1((x) {
       expect(path.value, 123);
       expect(x, 123);
     }));
@@ -306,7 +307,7 @@
       var path = new PathObserver(model, 'isNotEmpty');
       expect(path.value, false);
 
-      path.open(expectAsync((_) {
+      path.open(expectAsync1((_) {
         expect(path.value, true);
       }));
       model.add(123);
@@ -317,7 +318,7 @@
       var path = new PathObserver(model, 'isEmpty');
       expect(path.value, true);
 
-      path.open(expectAsync((_) {
+      path.open(expectAsync1((_) {
         expect(path.value, false);
       }));
       model.add(123);