added error handling test module

test/09_about_errors.js

@@ -0,0 +1,80 @@
+var Rx = require('rx'),
+Observable = Rx.Observable;
+
+QUnit.module('Error Handling');
+
+var __ = 'Fill in the blank';
+
+test('onError is called when Error is thrown', function () {
+  var result;
+  var throwingObservable = Observable.throw(new Error());
+
+  throwingObservable.subscribe(
+    function (x) { result = 'safe & sound'; }, //onNext
+    function (e) { result = 'uh oh'; } //onError
+  );
+
+  equal(result, __);
+});
+
+test('class level catch moves to the next sequence on error', function () {
+  Observable.catch(
+    Observable.throw(new Error('If at first you dont succeed')),
+    Observable.throw(new Error('Try, try, try again')),
+    Observable.just(42)
+  ).subscribe(function (x) { equal(x, __); });
+});
+
+test('instance level catch moves to the next sequence on error', function () {
+  var throwingObservable = Observable.throw(new Error(__));
+
+  throwingObservable.catch(function (e) {
+    return e.message === 'help' ? Observable.just('I need somebody') : Observable.just('not just anybody');
+  }).subscribe(function (msg) { equal(msg, 'I need somebody'); });
+});
+
+test('continue a stream that is terminated normally or by an Error with the next stream ', function () {
+  var easy = [];
+  var source = Rx.Observable.onErrorResumeNext(
+    Rx.Observable.just('A'),
+    Rx.Observable.throw(new Error()),
+    Rx.Observable.just('B'),
+    Rx.Observable.throw(new Error()),
+    Rx.Observable.just('C')
+  ).subscribe(easy.push.bind(easy));
+
+  equal(easy.join(''), __);
+});
+
+asyncTest('retry a sequence a number of times', function () {
+  var count = 0;
+  var received;
+  var source = Rx.Observable.interval(10)
+  .selectMany(function () {
+    if (++count < 2) {
+      return Rx.Observable.throw(new Error());
+    }
+    return Rx.Observable.return(42);
+  })
+  .retry(__).subscribe(
+    function (x) { received = x; },
+    function (e) { /*woops*/}
+  );
+
+  setTimeout(function () {
+    start();
+    equal(received, 42);
+  }, 50);
+});
+
+test('finally invokes action after the sequence ends', function () {
+  var result = [];
+  Observable.throw(new Error())
+  .finally(function () { result.push('some good news')})
+  .subscribe(
+    function (x) { result.push('hope for the best'); },
+    function (e) { result.push('finally'); }
+  );
+
+  equal(result.join(' '), __);
+});