#909: Update tests to JUnit 5

By: DerFrZocker <derrieple@gmail.com>

paper-api/src/test/java/org/bukkit/support/MatcherAssert.java

@@ -0,0 +1,36 @@
+package org.bukkit.support;
+
+import org.hamcrest.Matcher;
+
+/**
+ * Custom assertThat methods, where the reason is put at the end of the method call.
+ * To better match with JUnit 5 argument order and also help with readability for longer reasons.
+ * <br>
+ * <pre>
+ * assertThat(String.format("""
+ *         The block data created for the material %s is not an instance of the data class from that material.
+ *         """, material), blockData, is(instanceOf(expectedClass)));
+ * </pre>
+ * vs.
+ * <pre>
+ * assertThat(blockData, is(instanceOf(expectedClass)), String.format("""
+ *         The block data created for the material %s is not an instance of the data class from that material.
+ *         """, material));
+ * </pre>
+ */
+public final class MatcherAssert {
+
+    private MatcherAssert() {}
+
+    public static <T> void assertThat(T actual, Matcher<? super T> matcher) {
+        org.hamcrest.MatcherAssert.assertThat(actual, matcher);
+    }
+
+    public static <T> void assertThat(T actual, Matcher<? super T> matcher, String reason) {
+        org.hamcrest.MatcherAssert.assertThat(reason, actual, matcher);
+    }
+
+    public static void assertThat(boolean assertion, String reason) {
+        org.hamcrest.MatcherAssert.assertThat(reason, assertion);
+    }
+}