Merge branch '6.2.x'

spring-core/src/test/java/org/springframework/core/env/AbstractPropertyResolverTests.java

@@ -0,0 +1,120 @@
+/*
+ * Copyright 2002-2025 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.env;
+
+import java.util.stream.IntStream;
+
+import org.jspecify.annotations.Nullable;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.core.SpringProperties;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException;
+import static org.springframework.core.env.AbstractPropertyResolver.DEFAULT_PLACEHOLDER_ESCAPE_CHARACTER_PROPERTY_NAME;
+import static org.springframework.core.env.AbstractPropertyResolver.UNDEFINED_ESCAPE_CHARACTER;
+
+/**
+ * Unit tests for {@link AbstractPropertyResolver}.
+ *
+ * @author Sam Brannen
+ * @since 6.2.7
+ */
+class AbstractPropertyResolverTests {
+
+	@BeforeEach
+	void resetStateBeforeEachTest() {
+		resetState();
+	}
+
+	@AfterAll
+	static void resetState() {
+		AbstractPropertyResolver.defaultEscapeCharacter = UNDEFINED_ESCAPE_CHARACTER;
+		setSpringProperty(null);
+	}
+
+
+	@Test
+	void getDefaultEscapeCharacterWithSpringPropertySetToCharacterMinValue() {
+		setSpringProperty("" + Character.MIN_VALUE);
+
+		assertThatIllegalArgumentException()
+				.isThrownBy(AbstractPropertyResolver::getDefaultEscapeCharacter)
+				.withMessage("Value for property [%s] must not be Character.MIN_VALUE",
+						DEFAULT_PLACEHOLDER_ESCAPE_CHARACTER_PROPERTY_NAME);
+
+		assertThat(AbstractPropertyResolver.defaultEscapeCharacter).isEqualTo(UNDEFINED_ESCAPE_CHARACTER);
+	}
+
+	@Test
+	void getDefaultEscapeCharacterWithSpringPropertySetToXyz() {
+		setSpringProperty("XYZ");
+
+		assertThatIllegalArgumentException()
+				.isThrownBy(AbstractPropertyResolver::getDefaultEscapeCharacter)
+				.withMessage("Value [XYZ] for property [%s] must be a single character or an empty string",
+						DEFAULT_PLACEHOLDER_ESCAPE_CHARACTER_PROPERTY_NAME);
+
+		assertThat(AbstractPropertyResolver.defaultEscapeCharacter).isEqualTo(UNDEFINED_ESCAPE_CHARACTER);
+	}
+
+	@Test
+	void getDefaultEscapeCharacterWithSpringPropertySetToEmptyString() {
+		setSpringProperty("");
+		assertEscapeCharacter(null);
+	}
+
+	@Test
+	void getDefaultEscapeCharacterWithoutSpringPropertySet() {
+		assertEscapeCharacter('\\');
+	}
+
+	@Test
+	void getDefaultEscapeCharacterWithSpringPropertySetToBackslash() {
+		setSpringProperty("\\");
+		assertEscapeCharacter('\\');
+	}
+
+	@Test
+	void getDefaultEscapeCharacterWithSpringPropertySetToTilde() {
+		setSpringProperty("~");
+		assertEscapeCharacter('~');
+	}
+
+	@Test
+	void getDefaultEscapeCharacterFromMultipleThreads() {
+		setSpringProperty("~");
+
+		IntStream.range(1, 32).parallel().forEach(__ ->
+				assertThat(AbstractPropertyResolver.getDefaultEscapeCharacter()).isEqualTo('~'));
+
+		assertThat(AbstractPropertyResolver.defaultEscapeCharacter).isEqualTo('~');
+	}
+
+
+	private static void setSpringProperty(String value) {
+		SpringProperties.setProperty(DEFAULT_PLACEHOLDER_ESCAPE_CHARACTER_PROPERTY_NAME, value);
+	}
+
+	private static void assertEscapeCharacter(@Nullable Character expected) {
+		assertThat(AbstractPropertyResolver.getDefaultEscapeCharacter()).isEqualTo(expected);
+		assertThat(AbstractPropertyResolver.defaultEscapeCharacter).isEqualTo(expected);
+	}
+
+}