Enable all compiler warnings for Java test sources

Author: marcphilipp

gradle/plugins/common/src/main/kotlin/junitbuild.java-library-conventions.gradle.kts

@@ -274,8 +274,7 @@ tasks.compileJava {
 tasks.compileTestJava {
 	// See: https://docs.oracle.com/en/java/javase/12/tools/javac.html
 	options.compilerArgs.addAll(listOf(
-			"-Xlint", // Enables all recommended warnings.
-			"-Xlint:-overrides", // Disables "method overrides" warnings.
+			"-Xlint:all", // Enables all recommended warnings.
 			"-Werror", // Terminates compilation when warnings occur.
 			"-parameters" // Generates metadata for reflection on method parameters.
 	))

jupiter-tests/src/test/java/org/junit/jupiter/api/AssertEqualsAssertionsTests.java

@@ -752,6 +752,7 @@ void chars() {
 
 	// -------------------------------------------------------------------------
 
+	@SuppressWarnings("overrides")
 	private static class EqualsThrowsException {
 
 		@Override

jupiter-tests/src/test/java/org/junit/jupiter/api/AssertNotEqualsAssertionsTests.java

@@ -757,6 +757,7 @@ void chars() {
 
 	// -------------------------------------------------------------------------
 
+	@SuppressWarnings("overrides")
 	private static class EqualsThrowsExceptionClass {
 
 		@Override

platform-tests/src/test/java/org/junit/platform/commons/support/conversion/FallbackStringToObjectConverterTests.java

@@ -167,6 +167,11 @@ public boolean equals(Object obj) {
 			return Objects.equals(this.title, that.title);
 		}
 
+		@Override
+		public int hashCode() {
+			return Objects.hash(title);
+		}
+
 	}
 
 	static class Journal {
@@ -188,6 +193,11 @@ public boolean equals(Object obj) {
 			return Objects.equals(this.title, that.title);
 		}
 
+		@Override
+		public int hashCode() {
+			return Objects.hash(title);
+		}
+
 	}
 
 	static class Newspaper {
@@ -217,6 +227,11 @@ public boolean equals(Object obj) {
 			return Objects.equals(this.title, that.title);
 		}
 
+		@Override
+		public int hashCode() {
+			return Objects.hash(title);
+		}
+
 	}
 
 	static class Magazine {