Add requireState(..) assertion method to RedisAssertions.

Use RedisAssertions.requireState(..) in RedisAccessor.getRequiredConnectionFactory().

Closes spring-projects#2611

Author: jxblum

src/main/java/org/springframework/data/redis/core/RedisAccessor.java

@@ -19,6 +19,7 @@
 import org.apache.commons.logging.LogFactory;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.data.redis.connection.RedisConnectionFactory;
+import org.springframework.data.redis.util.RedisAssertions;
 import org.springframework.lang.NonNull;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
@@ -64,12 +65,7 @@ public RedisConnectionFactory getConnectionFactory() {
 	 */
 	@NonNull
 	public RedisConnectionFactory getRequiredConnectionFactory() {
-
-		RedisConnectionFactory connectionFactory = getConnectionFactory();
-
-		Assert.state(connectionFactory != null, "RedisConnectionFactory is required");
-
-		return connectionFactory;
+		return RedisAssertions.requireState(getConnectionFactory(), "RedisConnectionFactory is required");
 	}
 
 	/**

src/main/java/org/springframework/data/redis/util/RedisAssertions.java

@@ -56,4 +56,33 @@ public static <T> T requireObject(@Nullable T target, Supplier<String> message)
 		Assert.notNull(target, message);
 		return target;
 	}
+
+	/**
+	 * Asserts the given {@link Object} is not {@literal null}.
+	 *
+	 * @param <T> {@link Class type} of {@link Object} being asserted.
+	 * @param target {@link Object} to evaluate.
+	 * @param message {@link String} containing the message for the thrown exception.
+	 * @param arguments array of {@link Object} arguments used to format the {@link String message}.
+	 * @return the given {@link Object}.
+	 * @throws IllegalArgumentException if the {@link Object target} is {@literal null}.
+	 * @see #requireObject(Object, Supplier)
+	 */
+	public static <T> T requireState(@Nullable T target, String message, Object... arguments) {
+		return requireState(target, () -> String.format(message, arguments));
+	}
+
+	/**
+	 * Asserts the given {@link Object} is not {@literal null}.
+	 *
+	 * @param <T> {@link Class type} of {@link Object} being asserted.
+	 * @param target {@link Object} to evaluate.
+	 * @param message {@link Supplier} supplying the message for the thrown exception.
+	 * @return the given {@link Object}.
+	 * @throws IllegalArgumentException if the {@link Object target} is {@literal null}.
+	 */
+	public static <T> T requireState(@Nullable T target, Supplier<String> message) {
+		Assert.state(target != null, message);
+		return target;
+	}
 }

src/test/java/org/springframework/data/redis/util/RedisAssertionsUnitTests.java

@@ -17,6 +17,7 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
 import static org.mockito.Mockito.doReturn;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
@@ -79,4 +80,40 @@ public void requireObjectWithSupplierThrowsIllegalArgumentException() {
 		verify(this.mockSupplier, times(1)).get();
 		verifyNoMoreInteractions(this.mockSupplier);
 	}
+
+	@Test
+	public void requireStateWithMessageAndArgumentsIsSuccessful() {
+		assertThat(RedisAssertions.requireState("test", "Mock message")).isEqualTo("test");
+	}
+
+	@Test
+	public void requireStateWithMessageAndArgumentsThrowsIllegalStateException() {
+
+		assertThatIllegalStateException()
+			.isThrownBy(() -> RedisAssertions.requireState(null, "This is a %s", "test"))
+			.withMessage("This is a test")
+			.withNoCause();
+	}
+
+	@Test
+	public void requireStateWithSupplierIsSuccessful() {
+
+		assertThat(RedisAssertions.requireState("test", this.mockSupplier)).isEqualTo("test");
+
+		verifyNoInteractions(this.mockSupplier);
+	}
+
+	@Test
+	public void requiredStateWithSupplierThrowsIllegalStateException() {
+
+		doReturn("Mock message").when(this.mockSupplier).get();
+
+		assertThatIllegalStateException()
+			.isThrownBy(() -> RedisAssertions.requireState(null, this.mockSupplier))
+			.withMessage("Mock message")
+			.withNoCause();
+
+		verify(this.mockSupplier, times(1)).get();
+		verifyNoMoreInteractions(this.mockSupplier);
+	}
 }