Class CollectorTester<T extends @Nullable Object, A extends @Nullable Object, R extends @Nullable Object>

java.lang.Object

com.google.common.testing.CollectorTester<T,A,R>

@GwtCompatible
@NullMarked
public final class CollectorTester<T extends @Nullable Object, A extends @Nullable Object, R extends @Nullable Object>
extends Object

Tester for Collector implementations.

Example usage:

 CollectorTester.of(Collectors.summingInt(Integer::parseInt))
     .expectCollects(3, "1", "2")
     .expectCollects(10, "1", "4", "3", "2")
     .expectCollects(5, "-3", "0", "8");
 

Since:

21.0

Author:

Louis Wasserman

Method Summary

Modifier and Type	Method	Description
final CollectorTester<T,A,R>	expectCollects(R expectedResult, T... inputs)	Verifies that the specified expected result is always produced by collecting the specified inputs, regardless of how the elements are divided.
static <T extends @Nullable Object, A extends @Nullable Object, R extends @Nullable Object> CollectorTester<T,A,R>	of(Collector<T,A,R> collector)	Creates a CollectorTester for the specified Collector.
static <T extends @Nullable Object, A extends @Nullable Object, R extends @Nullable Object> CollectorTester<T,A,R>	of(Collector<T,A,R> collector, BiPredicate<? super R, ? super R> equivalence)	Creates a CollectorTester for the specified Collector.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

of

public static <T extends @Nullable Object, A extends @Nullable Object, R extends @Nullable Object>
CollectorTester<T,A,R> of(Collector<T,A,R> collector)

Creates a CollectorTester for the specified Collector. The result of the Collector will be compared to the expected value using Object.equals(java.lang.Object).

of

public static <T extends @Nullable Object, A extends @Nullable Object, R extends @Nullable Object>
CollectorTester<T,A,R> of(Collector<T,A,R> collector,
 BiPredicate<? super R, ? super R> equivalence)

Creates a CollectorTester for the specified Collector. The result of the Collector will be compared to the expected value using the specified equivalence.

expectCollects

@SafeVarargs
@CanIgnoreReturnValue
public final CollectorTester<T,A,R> expectCollects(R expectedResult,
 T... inputs)

Verifies that the specified expected result is always produced by collecting the specified inputs, regardless of how the elements are divided.