Add hasNullValue and doesNotHaveNullValue to AtomicReferenceAssert

Fix #2969

assertj-core/src/main/java/org/assertj/core/api/AtomicReferenceAssert.java

@@ -163,4 +163,39 @@ public AtomicReferenceAssert<V> hasValueSatisfying(Consumer<? super V> requireme
     return myself;
   }
 
+  /**
+   * Verifies that the atomic under test has the {@code null} value.
+   * <p>
+   * Example:
+   * <pre><code class='java'> // assertion succeeds
+   * assertThat(new AtomicReference(null)).hasNullValue();
+   *
+   * // assertion fails
+   * assertThat(new AtomicReference("foo")).hasNullValue();</code></pre>
+   *
+   * @return {@code this} assertion object.
+   * @throws AssertionError if the atomic under test does not have the null value.
+   * @since 3.25.0
+   */
+  public AtomicReferenceAssert<V> hasNullValue() {
+    return hasValue(null);
+  }
+
+  /**
+   * Verifies that the atomic under test does not have the {@code null} value.
+   * <p>
+   * Example:
+   * <pre><code class='java'> // assertion succeeds
+   * assertThat(new AtomicReference("foo")).doesNotHaveNullValue();
+   *
+   * // assertion fails
+   * assertThat(new AtomicReference(null)).doesNotHaveNullValue();</code></pre>
+   *
+   * @return {@code this} assertion object.
+   * @throws AssertionError if the atomic under test has the null value.
+   * @since 3.25.0
+   */
+  public AtomicReferenceAssert<V> doesNotHaveNullValue() {
+    return doesNotHaveValue(null);
+  }
 }

assertj-core/src/test/java/org/assertj/core/api/atomic/reference/AtomicReferenceAssert_doesNotHaveNullValue_Test.java

@@ -0,0 +1,43 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ * Copyright 2012-2023 the original author or authors.
+ */
+package org.assertj.core.api.atomic.reference;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.BDDAssertions.then;
+import static org.assertj.core.error.ShouldNotContainValue.shouldNotContainValue;
+import static org.assertj.core.util.AssertionsUtil.expectAssertionError;
+
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.junit.jupiter.api.Test;
+
+class AtomicReferenceAssert_doesNotHaveNullValue_Test {
+
+  @Test
+  void should_pass_when_actual_does_not_have_the_null_value() {
+    // GIVEN
+    AtomicReference<String> actual = new AtomicReference<>("foo");
+    // WHEN/THEN
+    then(actual).doesNotHaveNullValue();
+  }
+
+  @Test
+  void should_fail_when_actual_has_the_null_value() {
+    // GIVEN
+    AtomicReference<String> actual = new AtomicReference<>(null);
+    // WHEN
+    AssertionError assertionError = expectAssertionError(() -> assertThat(actual).doesNotHaveNullValue());
+    // THEN
+    then(assertionError).hasMessage(shouldNotContainValue(actual, null).create());
+  }
+}

assertj-core/src/test/java/org/assertj/core/api/atomic/reference/AtomicReferenceAssert_hasNullValue_Test.java

@@ -0,0 +1,43 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ * Copyright 2012-2023 the original author or authors.
+ */
+package org.assertj.core.api.atomic.reference;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.BDDAssertions.then;
+import static org.assertj.core.error.ShouldHaveValue.shouldHaveValue;
+import static org.assertj.core.util.AssertionsUtil.expectAssertionError;
+
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.junit.jupiter.api.Test;
+
+class AtomicReferenceAssert_hasNullValue_Test {
+
+  @Test
+  void should_pass_when_actual_has_the_null_value() {
+    // GIVEN
+    AtomicReference<String> actual = new AtomicReference<>(null);
+    // WHEN/THEN
+    then(actual).hasNullValue();
+  }
+
+  @Test
+  void should_fail_when_actual_does_not_have_the_null_value() {
+    // GIVEN
+    AtomicReference<String> actual = new AtomicReference<>("foo");
+    // WHEN
+    AssertionError assertionError = expectAssertionError(() -> assertThat(actual).hasNullValue());
+    // THEN
+    then(assertionError).hasMessage(shouldHaveValue(actual, null).create());
+  }
+}