Add doOnTerminate to Single/Maybe for consistency #6386

skryvets · 2019-01-26T16:15:33Z

This PR adds doOnTerminate operator to Single and Maybe.

Resolves: #6379.

codecov · 2019-01-26T16:30:39Z

Codecov Report

Merging #6386 into 2.x will increase coverage by 0.05%.
The diff coverage is 100%.

@@             Coverage Diff              @@
##                2.x    #6386      +/-   ##
============================================
+ Coverage     98.23%   98.28%   +0.05%     
- Complexity     6287     6299      +12     
============================================
  Files           673      675       +2     
  Lines         45092    45156      +64     
  Branches       6239     6239              
============================================
+ Hits          44297    44383      +86     
+ Misses          256      238      -18     
+ Partials        539      535       -4

Impacted Files	Coverage Δ	Complexity Δ
...x/internal/operators/maybe/MaybeDoOnTerminate.java	`100% <100%> (ø)`	`2 <2> (?)`
src/main/java/io/reactivex/Maybe.java	`100% <100%> (ø)`	`173 <1> (+1)`	⬆️
...internal/operators/single/SingleDoOnTerminate.java	`100% <100%> (ø)`	`2 <2> (?)`
src/main/java/io/reactivex/Single.java	`100% <100%> (ø)`	`149 <1> (+1)`	⬆️
.../operators/observable/ObservableFlatMapSingle.java	`89.55% <0%> (-5.98%)`	`2% <0%> (ø)`
...nternal/operators/parallel/ParallelReduceFull.java	`91.08% <0%> (-3.97%)`	`2% <0%> (ø)`
...tivex/internal/observers/FutureSingleObserver.java	`94.33% <0%> (-3.78%)`	`24% <0%> (-1%)`
.../operators/mixed/FlowableConcatMapCompletable.java	`97.43% <0%> (-2.57%)`	`2% <0%> (ø)`
...perators/mixed/ObservableSwitchMapCompletable.java	`97.89% <0%> (-2.11%)`	`3% <0%> (ø)`
...nternal/operators/observable/ObservableWindow.java	`98% <0%> (-2%)`	`3% <0%> (ø)`
... and 28 more

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akarnokd · 2019-01-26T16:25:28Z

src/main/java/io/reactivex/Maybe.java

@@ -2892,6 +2892,31 @@ public final T blockingGet(T defaultValue) {
        ));
    }

+    /**
+     * Calls the shared consumer with the given onTerminate callback for each


This sentence makes no sense. Please word it like the other similar operators: http://reactivex.io/RxJava/2.x/javadoc/io/reactivex/Completable.html#doOnTerminate-io.reactivex.functions.Action-

akarnokd · 2019-01-26T16:27:27Z

src/test/java/io/reactivex/maybe/MaybeTest.java

@@ -826,6 +827,53 @@ public void accept(Disposable v) throws Exception {
        .assertFailure(TestException.class);
    }

+    @Test(expected = NullPointerException.class)


Please put these unit test into their own files and also verify the cases when the onTerminate callback fail.

Implemented

akarnokd · 2019-01-26T16:27:57Z

src/main/java/io/reactivex/internal/operators/single/SingleDoOnTerminate.java

+                onTerminate.run();
+            } catch (Throwable ex) {
+                Exceptions.throwIfFatal(ex);
+                downstream.onError(ex);


This should be a composite error with the original error followed by the handler crash. Example: https://github.com/ReactiveX/RxJava/blob/2.x/src/main/java/io/reactivex/internal/operators/completable/CompletablePeek.java#L92

Implemented

akarnokd · 2019-01-27T15:59:57Z

src/main/java/io/reactivex/Maybe.java

+     */
+    @CheckReturnValue
+    @NonNull
+    @SchedulerSupport(SchedulerSupport.NONE)


Please add @Experimental.

akarnokd · 2019-01-27T16:00:17Z

src/main/java/io/reactivex/Maybe.java

+     * @return the new Maybe instance
+     * @see <a href="http://reactivex.io/documentation/operators/do.html">ReactiveX operators documentation: Do</a>
+     * @see #doOnTerminate(Action)
+     */


Please add @since 2.2.7 - experimental.

akarnokd · 2019-01-27T16:00:47Z

src/main/java/io/reactivex/Single.java

+     * @return the new Single instance
+     * @see <a href="http://reactivex.io/documentation/operators/do.html">ReactiveX operators documentation: Do</a>
+     * @see #doOnTerminate(Action)
+     * @since 2.0


Please use the next minor version: @since 2.2.7 - experimental.

akarnokd · 2019-01-27T16:00:58Z

src/main/java/io/reactivex/Single.java

+    @CheckReturnValue
+    @NonNull
+    @SchedulerSupport(SchedulerSupport.NONE)
+    public final Single<T> doOnTerminate(final Action onTerminate) {


Please add @Experimental.

akarnokd · 2019-01-27T16:03:41Z

src/test/java/io/reactivex/internal/operators/maybe/MaybeDoOnTerminateTest.java

+            public void run() {
+                atomicBoolean.set(true);
+            }
+        }).subscribe();


You should use .test().assertResult(1); instead of just subscribing blindly.

akarnokd · 2019-01-27T16:03:56Z

src/test/java/io/reactivex/internal/operators/maybe/MaybeDoOnTerminateTest.java

+                atomicBoolean.set(true);
+            }
+        })
+        .subscribe();


You should use .test().assertResult(1); instead.

akarnokd · 2019-01-27T16:04:11Z

src/test/java/io/reactivex/internal/operators/single/SingleDoOnTerminateTest.java

+            public void run() throws Exception {
+                atomicBoolean.set(true);
+            }
+        }).subscribe();


You should use .test().assertResult(1); instead.

akarnokd · 2019-01-27T16:04:31Z

src/test/java/io/reactivex/internal/operators/single/SingleDoOnTerminateTest.java

+            }
+        });
+
+        try {


Why the testing style change?

Refactored to match the rest of the testing style

skryvets · 2019-01-28T00:05:26Z

src/test/java/io/reactivex/internal/operators/maybe/MaybeDoOnTerminateTest.java

+            }
+        })
+        .test()
+        .assertResult();


@akarnokd, as you suggested I've tried to use .assertResult(1) which results in the test failure. I found similar pattern here, where assertResult() has no params since Maybe doesn't emit a value. Please correct me if I'm wrong.

Think about it a bit. You have an empty source and you want to verify it is still empty at the end.

akarnokd · 2019-01-28T10:10:35Z

src/test/java/io/reactivex/internal/operators/single/SingleDoOnTerminateTest.java

+            }
+        })
+        .test()
+        .assertFailure(CompositeException.class);


Please verify that the correct inner exceptions are received. Example: https://github.com/ReactiveX/RxJava/blob/2.x/src/test/java/io/reactivex/internal/operators/completable/CompletableDoOnTest.java#L52

akarnokd · 2019-01-28T10:10:48Z

src/test/java/io/reactivex/internal/operators/maybe/MaybeDoOnTerminateTest.java

+            }
+        })
+        .test()
+        .assertFailure(CompositeException.class);


Please verify that the correct inner exceptions are received. Example: https://github.com/ReactiveX/RxJava/blob/2.x/src/test/java/io/reactivex/internal/operators/completable/CompletableDoOnTest.java#L52

skryvets · 2019-01-29T01:46:21Z

src/test/java/io/reactivex/internal/operators/maybe/MaybeDoOnTerminateTest.java

+            }
+        })
+        .test()
+        .assertNoValues();


I came to a conclusion that assertNoValues() would be the right choice. I also considered assertEmpty() method, but this one will not work as onComplete event is triggered.

Thanks for pointing me in a right direction.

AssertNoValues doesn't verify the lack of errors. Please put assertResult back.

I thought your previous comment mentioned that it was a wrong approach. Maybe I misunderstood. Is it still correct to use assertResult()?

I put it back anyways according to your last review.

You misunderstood me. If a source has no values, there is no reason to put any value into the parameter of assertResult(). A no-arg assertResult verifies exactly that the outcome is no items and no errors.

Got it. Sorry for the for the back and forth from my side.

skryvets · 2019-01-29T11:02:50Z

All improvements and fixes have been implemented

akarnokd requested changes Jan 26, 2019

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akarnokd requested changes Jan 27, 2019

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skryvets commented Jan 28, 2019

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akarnokd added Enhancement 2.x labels Jan 28, 2019

akarnokd added this to the 2.2 backlog milestone Jan 28, 2019

akarnokd reviewed Jan 28, 2019

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skryvets commented Jan 29, 2019

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Add doOnTerminate to Single/Maybe for consistency (#6379)

3e8284b

akarnokd approved these changes Jan 29, 2019

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vanniktech approved these changes Jan 29, 2019

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akarnokd merged commit 6e266af into ReactiveX:2.x Jan 29, 2019

akarnokd mentioned this pull request Feb 19, 2019

2.2.7 release preparations #6412

Closed

+                          }
+                      });
+                      try {

Add doOnTerminate to Single/Maybe for consistency #6386

Add doOnTerminate to Single/Maybe for consistency #6386

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skryvets commented Jan 26, 2019

codecov bot commented Jan 26, 2019 • edited

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skryvets Jan 27, 2019 • edited

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skryvets commented Jan 29, 2019

codecov bot commented Jan 26, 2019 •

edited

skryvets Jan 27, 2019 •

edited