How to use flatMap method of org.assertj.core.api.AbstractOptionalAssert class

Best Assertj code snippet using org.assertj.core.api.AbstractOptionalAssert.flatMap

Source:AbstractOptionalAssert.java

...325    if (actual.get() != expectedValue) throwAssertionError(shouldContainSame(actual, expectedValue));326    return myself;327  }328  /**329   * Call {@link Optional#flatMap(Function) flatMap} on the {@code Optional} under test, assertions chained afterwards are performed on the {@code Optional} resulting from the flatMap call.330   * <p>331   * Examples:332   * <pre><code class='java'> Function&lt;String, Optional&lt;String&gt;&gt; UPPER_CASE_OPTIONAL_STRING = 333   *       s -&gt; s == null ? Optional.empty() : Optional.of(s.toUpperCase());334   * 335   * // assertions succeed336   * assertThat(Optional.of("something")).contains("something")337   *                                     .flatMap(UPPER_CASE_OPTIONAL_STRING)338   *                                     .contains("SOMETHING");339   *                                     340   * assertThat(Optional.&lt;String&gt;empty()).flatMap(UPPER_CASE_OPTIONAL_STRING)341   *                                     .isEmpty();342   *                                     343   * assertThat(Optional.&lt;String&gt;ofNullable(null)).flatMap(UPPER_CASE_OPTIONAL_STRING)344   *                                              .isEmpty();345   *                                     346   * // assertion fails347   * assertThat(Optional.of("something")).flatMap(UPPER_CASE_OPTIONAL_STRING)348   *                                     .contains("something");</code></pre>349   *350   * @param <U> the type wrapped in the {@link Optional} after the {@link Optional#flatMap(Function) flatMap} operation.351   * @param mapper the {@link Function} to use in the {@link Optional#flatMap(Function) flatMap} operation.352   * @return a new {@link AbstractOptionalAssert} for assertions chaining on the flatMap of the Optional.353   * @throws AssertionError if the actual {@link Optional} is null.354   * @since 3.6.0355   */356  @CheckReturnValue357  public <U> AbstractOptionalAssert<?, U> flatMap(Function<? super VALUE, Optional<U>> mapper) {358    isNotNull();359    return assertThat(actual.flatMap(mapper));360  }361  /**362   * Call {@link Optional#map(Function) map} on the {@code Optional} under test, assertions chained afterwards are performed on the {@code Optional} resulting from the map call.363   * <p>364   * Examples:365   * <pre><code class='java'> // assertions succeed 366   * assertThat(Optional.&lt;String&gt;empty()).map(String::length)367   *                                     .isEmpty();368   * 369   * assertThat(Optional.of("42")).contains("42")370   *                              .map(String::length)371   *                              .contains(2);372   *                              373   * // assertion fails...

flatMap

Using AI Code Generation

1import static org.assertj.core.api.Assertions.assertThat;2import java.util.Optional;3import org.junit.Test;4public class OptionalFlatMapTest {5    public void whenOptionalHasValue_thenFlatMapReturnsValue() {6        String name = "John";7        Optional<String> opt = Optional.of(name);8        assertThat(opt.flatMap(Optional::of)).isEqualTo(Optional.of(name));9    }10    public void whenOptionalEmpty_thenFlatMapReturnsEmpty() {11        Optional<String> opt = Optional.empty();12        assertThat(opt.flatMap(Optional::of)).isEqualTo(Optional.empty());13    }14}15import static org.assertj.core.api.Assertions.assertThat;16import java.util.Optional;17import org.junit.Test;18public class OptionalFlatMapTest {19    public void whenOptionalHasValue_thenFlatMapReturnsValue() {20        String name = "John";21        Optional<String> opt = Optional.of(name);22        assertThat(opt.flatMap(Optional::of)).isEqualTo(Optional.of(name));23    }24    public void whenOptionalEmpty_thenFlatMapReturnsEmpty() {25        Optional<String> opt = Optional.empty();26        assertThat(opt.flatMap(Optional::of)).isEqualTo(Optional.empty());27    }28}

flatMap

Using AI Code Generation

1import org.assertj.core.api.Assertions.assertThat2import org.junit.Test3import java.util.Optional4class OptionalTest {5    fun testOptional() {6        val optional = Optional.of("abc")7        assertThat(optional).isPresent8        assertThat(optional).hasValue("abc")9        assertThat(optional).hasValueSatisfying { it.length() == 3 }10        assertThat(optional).contains("abc")11        assertThat(optional).contains("a", "b", "c")

flatMap

Using AI Code Generation

1import org.assertj.core.api.Assertions.assertThat;2import java.util.Optional;3Optional<String> opt = Optional.of("value");4assertThat(opt).flatMap(x -> x).isEqualTo("value");5import org.assertj.core.api.Assertions.assertThat;6import java.util.Optional;7Optional<String> opt = Optional.of("value");8assertThat(opt).flatMap(x -> x).isEqualTo("value");

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