BatchingSpliterator.java

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/*
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 * Copyright 2014-2026 Grzegorz Piwowarek, https://4comprehension.com/
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 *
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 * Licensed under the Apache License, Version 2.0 (the "License");
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 * you may not use this file except in compliance with the License.
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 * You may obtain a copy of the License at
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 *
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 * https://www.apache.org/licenses/LICENSE-2.0
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 *
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 * Unless required by applicable law or agreed to in writing, software
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 * distributed under the License is distributed on an "AS IS" BASIS,
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 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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 * See the License for the specific language governing permissions and
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 * limitations under the License.
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 */
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package com.pivovarit.collectors;
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import java.util.ArrayList;
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import java.util.List;
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import java.util.Objects;
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import java.util.Spliterator;
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import java.util.function.Consumer;
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import java.util.function.Function;
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import java.util.stream.Stream;
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import static java.util.stream.Stream.empty;
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import static java.util.stream.Stream.of;
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import static java.util.stream.StreamSupport.stream;
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/**
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 * @author Grzegorz Piwowarek
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 */
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final class BatchingSpliterator<T> implements Spliterator<List<T>> {
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    private final List<T> source;
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    private int chunks;
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    private int chunkSize;
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    private int consumed;
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    BatchingSpliterator(List<T> list, int batches) {
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        Objects.requireNonNull(list, "list can't be null");
43 2 1. <init> : changed conditional boundary → KILLED
2. <init> : negated conditional → KILLED
 
        if (batches < 1) {
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            throw new IllegalArgumentException("batches can't be lower than one");
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        }
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        source = list;
47 1 1. <init> : negated conditional → KILLED
 
        chunks = list.isEmpty() ? 0 : Math.min(batches, list.size());
48 1 1. <init> : Replaced double division with multiplication → KILLED
 
        chunkSize = (int) Math.ceil(((double) source.size()) / batches);
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    }
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    static <T> Stream<List<T>> partitioned(List<T> list, int numberOfParts) {
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        int size = list.size();
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54 1 1. partitioned : negated conditional → KILLED
 
        if (size == 0) {
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            return empty();
56 1 1. partitioned : negated conditional → KILLED
 
        } else if (numberOfParts == 1) {
57 1 1. partitioned : replaced return value with Stream.empty for com/pivovarit/collectors/BatchingSpliterator::partitioned → KILLED
 
            return of(list);
58 2 1. partitioned : changed conditional boundary → SURVIVED
2. partitioned : negated conditional → KILLED
 
        } else if (size <= numberOfParts) {
59 1 1. partitioned : replaced return value with Stream.empty for com/pivovarit/collectors/BatchingSpliterator::partitioned → KILLED
 
            return asSingletonListStream(list);
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        } else {
61 1 1. partitioned : replaced return value with Stream.empty for com/pivovarit/collectors/BatchingSpliterator::partitioned → KILLED
 
            return stream(new BatchingSpliterator<>(list, numberOfParts), false);
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        }
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    }
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    private static <T> Stream<List<T>> asSingletonListStream(List<T> list) {
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        Stream.Builder<List<T>> acc = Stream.builder();
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        for (T t : list) {
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            acc.add(List.of(t));
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        }
70 1 1. asSingletonListStream : replaced return value with Stream.empty for com/pivovarit/collectors/BatchingSpliterator::asSingletonListStream → KILLED
 
        return acc.build();
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    }
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    static <T, R> Function<List<T>, List<R>> batching(Function<? super T, ? extends R> mapper) {
74 1 1. batching : replaced return value with null for com/pivovarit/collectors/BatchingSpliterator::batching → KILLED
 
        return batch -> {
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            List<R> list = new ArrayList<>(batch.size());
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            for (T t : batch) {
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                list.add(mapper.apply(t));
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            }
79 1 1. lambda$batching$0 : replaced return value with Collections.emptyList for com/pivovarit/collectors/BatchingSpliterator::lambda$batching$0 → KILLED
 
            return list;
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        };
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    }
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    @Override
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    public boolean tryAdvance(Consumer<? super List<T>> action) {
85 3 1. tryAdvance : changed conditional boundary → SURVIVED
2. tryAdvance : negated conditional → KILLED
3. tryAdvance : negated conditional → KILLED
 
        if (consumed < source.size() && chunks != 0) {
86 1 1. tryAdvance : Replaced integer addition with subtraction → KILLED
 
            int end = Math.min(source.size(), consumed + chunkSize);
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            List<T> batch = source.subList(consumed, end);
88 1 1. tryAdvance : Replaced integer addition with subtraction → KILLED
 
            consumed += batch.size();
89 3 1. tryAdvance : changed conditional boundary → SURVIVED
2. tryAdvance : negated conditional → KILLED
3. tryAdvance : Replaced integer subtraction with addition → KILLED
 
            if (--chunks > 0) {
90 2 1. tryAdvance : Replaced integer subtraction with addition → KILLED
2. tryAdvance : Replaced double division with multiplication → KILLED
 
                chunkSize = (int) Math.ceil(((double) (source.size() - consumed)) / chunks);
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            }
92 1 1. tryAdvance : removed call to java/util/function/Consumer::accept → KILLED
 
            action.accept(batch);
93 1 1. tryAdvance : replaced boolean return with false for com/pivovarit/collectors/BatchingSpliterator::tryAdvance → KILLED
 
            return true;
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        } else {
95 1 1. tryAdvance : replaced boolean return with true for com/pivovarit/collectors/BatchingSpliterator::tryAdvance → TIMED_OUT
 
            return false;
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        }
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    }
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    @Override
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    public Spliterator<List<T>> trySplit() {
101 1 1. trySplit : Replaced integer subtraction with addition → KILLED
 
        int remaining = source.size() - consumed;
102 4 1. trySplit : changed conditional boundary → SURVIVED
2. trySplit : changed conditional boundary → SURVIVED
3. trySplit : negated conditional → KILLED
4. trySplit : negated conditional → KILLED
 
        if (remaining <= chunkSize || chunks <= 1) {
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            return null;
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        }
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106 1 1. trySplit : Replaced integer division with multiplication → KILLED
 
        int midChunks = chunks / 2;
107 1 1. trySplit : Replaced integer division with multiplication → KILLED
 
        int floor = remaining / chunks;
108 1 1. trySplit : Replaced integer modulus with multiplication → KILLED
 
        int larger = remaining % chunks;
109 5 1. trySplit : Replaced integer addition with subtraction → KILLED
2. trySplit : Replaced integer addition with subtraction → KILLED
3. trySplit : Replaced integer subtraction with addition → KILLED
4. trySplit : Replaced integer multiplication with division → KILLED
5. trySplit : Replaced integer multiplication with division → KILLED
 
        int midSize = Math.min(midChunks, larger) * (floor + 1) + Math.max(0, midChunks - larger) * floor;
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111 1 1. trySplit : Replaced integer addition with subtraction → KILLED
 
        var subList = source.subList(consumed, consumed + midSize);
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        var split = new BatchingSpliterator<>(subList, midChunks);
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114 1 1. trySplit : Replaced integer addition with subtraction → KILLED
 
        consumed += midSize;
115 1 1. trySplit : Replaced integer subtraction with addition → KILLED
 
        chunks -= midChunks;
116 2 1. trySplit : Replaced double division with multiplication → KILLED
2. trySplit : Replaced integer subtraction with addition → KILLED
 
        chunkSize = (int) Math.ceil(((double) (source.size() - consumed)) / chunks);
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118 1 1. trySplit : replaced return value with null for com/pivovarit/collectors/BatchingSpliterator::trySplit → KILLED
 
        return split;
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    }
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    @Override
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    public long estimateSize() {
123 1 1. estimateSize : replaced long return with 0 for com/pivovarit/collectors/BatchingSpliterator::estimateSize → KILLED
 
        return chunks;
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    }
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    @Override
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    public int characteristics() {
128 1 1. characteristics : replaced int return with 0 for com/pivovarit/collectors/BatchingSpliterator::characteristics → KILLED
 
        return IMMUTABLE | ORDERED | SIZED;
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    }
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}

Mutations

43

1.1
Location : <init>
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldReturnOneForSingleBatch()] changed conditional boundary → KILLED

2.2
Location : <init>
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldReturnOneForSingleBatch()] negated conditional → KILLED

47

1.1
Location : <init>
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldReturnOneForSingleBatch()] negated conditional → KILLED

48

1.1
Location : <init>
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldAdjustCorrectlyAfterTrySplit()] Replaced double division with multiplication → KILLED

54

1.1
Location : partitioned
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[method:shouldReturnSameListWhenBatchesIsOne()] negated conditional → KILLED

56

1.1
Location : partitioned
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[method:shouldReportCorrectSizeWhenMultipleBatches()] negated conditional → KILLED

57

1.1
Location : partitioned
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[method:shouldReturnSameListWhenBatchesIsOne()] replaced return value with Stream.empty for com/pivovarit/collectors/BatchingSpliterator::partitioned → KILLED

58

1.1
Location : partitioned
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[method:shouldReportCorrectSizeWhenMultipleBatches()] negated conditional → KILLED

2.2
Location : partitioned
Killed by : none changed conditional boundary → SURVIVED Covering tests

59

1.1
Location : partitioned
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[method:shouldPartitionToSingletonsWhenSizeLessThanBatches()] replaced return value with Stream.empty for com/pivovarit/collectors/BatchingSpliterator::partitioned → KILLED

61

1.1
Location : partitioned
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[method:shouldReportCorrectSizeWhenMultipleBatches()] replaced return value with Stream.empty for com/pivovarit/collectors/BatchingSpliterator::partitioned → KILLED

70

1.1
Location : asSingletonListStream
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[method:shouldPartitionToSingletonsWhenSizeLessThanBatches()] replaced return value with Stream.empty for com/pivovarit/collectors/BatchingSpliterator::asSingletonListStream → KILLED

74

1.1
Location : batching
Killed by : com.pivovarit.collectors.test.BasicProcessingTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.test.BasicProcessingTest]/[test-factory:shouldProcessAllElementsInOrder()]/[dynamic-test:#33] replaced return value with null for com/pivovarit/collectors/BatchingSpliterator::batching → KILLED

79

1.1
Location : lambda$batching$0
Killed by : com.pivovarit.collectors.test.BasicProcessingTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.test.BasicProcessingTest]/[test-factory:shouldProcessAllElementsInOrder()]/[dynamic-test:#33] replaced return value with Collections.emptyList for com/pivovarit/collectors/BatchingSpliterator::lambda$batching$0 → KILLED

85

1.1
Location : tryAdvance
Killed by : none changed conditional boundary → SURVIVED Covering tests

2.2
Location : tryAdvance
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldReturnZeroAfterAllConsumed()] negated conditional → KILLED

3.3
Location : tryAdvance
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldReturnZeroAfterAllConsumed()] negated conditional → KILLED

86

1.1
Location : tryAdvance
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldReturnZeroAfterAllConsumed()] Replaced integer addition with subtraction → KILLED

88

1.1
Location : tryAdvance
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldReturnZeroAfterAllConsumed()] Replaced integer addition with subtraction → KILLED

89

1.1
Location : tryAdvance
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[method:shouldNotExceedBoundsOnLargeChunkRecomputation()] negated conditional → KILLED

2.2
Location : tryAdvance
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldReturnZeroAfterAllConsumed()] Replaced integer subtraction with addition → KILLED

3.3
Location : tryAdvance
Killed by : none changed conditional boundary → SURVIVED Covering tests

90

1.1
Location : tryAdvance
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[method:shouldNotExceedBoundsForUnevenSplit()] Replaced integer subtraction with addition → KILLED

2.2
Location : tryAdvance
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[method:shouldNotExceedBoundsForUnevenSplit()] Replaced double division with multiplication → KILLED

92

1.1
Location : tryAdvance
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[method:shouldHandleSingleElementList()] removed call to java/util/function/Consumer::accept → KILLED

93

1.1
Location : tryAdvance
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldReturnZeroAfterAllConsumed()] replaced boolean return with false for com/pivovarit/collectors/BatchingSpliterator::tryAdvance → KILLED

95

1.1
Location : tryAdvance
Killed by : none replaced boolean return with true for com/pivovarit/collectors/BatchingSpliterator::tryAdvance → TIMED_OUT

101

1.1
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldHonourSizedContractAcrossPartialAdvanceAndSplitCombinations()] Replaced integer subtraction with addition → KILLED

102

1.1
Location : trySplit
Killed by : none changed conditional boundary → SURVIVED Covering tests

2.2
Location : trySplit
Killed by : none changed conditional boundary → SURVIVED Covering tests

3.3
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldAdjustCorrectlyAfterTrySplit()] negated conditional → KILLED

4.4
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldAdjustCorrectlyAfterTrySplit()] negated conditional → KILLED

106

1.1
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldAdjustCorrectlyAfterTrySplit()] Replaced integer division with multiplication → KILLED

107

1.1
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldAdjustCorrectlyAfterTrySplit()] Replaced integer division with multiplication → KILLED

108

1.1
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldNotOvercountRemainderAfterUnevenTrySplit()] Replaced integer modulus with multiplication → KILLED

109

1.1
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldHonourSizedContractAcrossPartialAdvanceAndSplitCombinations()] Replaced integer addition with subtraction → KILLED

2.2
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldAdjustCorrectlyAfterTrySplit()] Replaced integer addition with subtraction → KILLED

3.3
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldNotOvercountRemainderAfterUnevenTrySplit()] Replaced integer subtraction with addition → KILLED

4.4
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldHonourSizedContractAcrossPartialAdvanceAndSplitCombinations()] Replaced integer multiplication with division → KILLED

5.5
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[method:shouldSplitAndProcessIndependently()] Replaced integer multiplication with division → KILLED

111

1.1
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldAdjustCorrectlyAfterTrySplit()] Replaced integer addition with subtraction → KILLED

114

1.1
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldNotOvercountRemainderAfterUnevenTrySplit()] Replaced integer addition with subtraction → KILLED

115

1.1
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldAdjustCorrectlyAfterTrySplit()] Replaced integer subtraction with addition → KILLED

116

1.1
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldNotOvercountRemainderAfterUnevenTrySplit()] Replaced double division with multiplication → KILLED

2.2
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldNotOvercountRemainderAfterUnevenTrySplit()] Replaced integer subtraction with addition → KILLED

118

1.1
Location : trySplit
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldAdjustCorrectlyAfterTrySplit()] replaced return value with null for com/pivovarit/collectors/BatchingSpliterator::trySplit → KILLED

123

1.1
Location : estimateSize
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[nested-class:EstimateSizeTests]/[method:shouldReturnOneForSingleBatch()] replaced long return with 0 for com/pivovarit/collectors/BatchingSpliterator::estimateSize → KILLED

128

1.1
Location : characteristics
Killed by : com.pivovarit.collectors.BatchingSpliteratorTest.[engine:junit-jupiter]/[class:com.pivovarit.collectors.BatchingSpliteratorTest]/[method:shouldReportOrderedSizedAndSubSized()] replaced int return with 0 for com/pivovarit/collectors/BatchingSpliterator::characteristics → KILLED

Active mutators

Tests examined


Report generated by PIT 1.30.0 support