Introduce unit tests for IntegerToEnumConverterFactory

Closes gh-25292

spring-web/src/test/java/org/springframework/core/convert/support/IntegerToEnumConverterFactoryTests.java

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2002-2020 the original author or authors.
+ *
+ * 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
+ *
+ *      https://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.
+ */
+
+package org.springframework.core.convert.support;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.AssertionsForClassTypes.assertThatExceptionOfType;
+
+/**
+ * @author Adilson Antunes
+ */
+class IntegerToEnumConverterFactoryTests {
+
+
+	enum Colors {
+		RED,
+		BLUE,
+		GREEN
+	}
+
+	@Test
+	void convertIntegerToEnum() {
+		final IntegerToEnumConverterFactory enumConverterFactory = new IntegerToEnumConverterFactory();
+		assertThat(enumConverterFactory.getConverter(Colors.class).convert(0)).isEqualTo(Colors.RED);
+		assertThat(enumConverterFactory.getConverter(Colors.class).convert(1)).isEqualTo(Colors.BLUE);
+		assertThat(enumConverterFactory.getConverter(Colors.class).convert(2)).isEqualTo(Colors.GREEN);
+	}
+
+	@Test
+	void throwsArrayIndexOutOfBoundsExceptionIfInvalidEnumInteger() {
+		final IntegerToEnumConverterFactory enumConverterFactory = new IntegerToEnumConverterFactory();
+		assertThatExceptionOfType(ArrayIndexOutOfBoundsException.class)
+				.isThrownBy(() -> enumConverterFactory.getConverter(Colors.class).convert(999));
+	}
+
+
+}