Adds test case for sealed interface recursion

equalsverifier-17/src/test/java/nl/jqno/equalsverifier/integration/extended_contract/SealedTypesRecursionTest.java

@@ -0,0 +1,63 @@
+package nl.jqno.equalsverifier.integration.extended_contract;
+
+import java.util.Objects;
+import nl.jqno.equalsverifier.EqualsVerifier;
+import nl.jqno.equalsverifier.Warning;
+import org.junit.jupiter.api.Test;
+
+class SealedTypesRecursionTest {
+
+    @Test
+    public void testEV() {
+        EqualsVerifier
+            .forClass(A.class)
+            .suppress(Warning.STRICT_INHERITANCE, Warning.NONFINAL_FIELDS)
+            .verify();
+    }
+
+    class A {
+
+        public I sealedClassField;
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(sealedClassField);
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (!(obj instanceof A)) {
+                return false;
+            }
+            A other = (A) obj;
+            return Objects.equals(sealedClassField, other.sealedClassField);
+        }
+    }
+
+    public sealed interface I permits E {}
+
+    public final class E implements I {
+
+        public A referenceToA;
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(referenceToA);
+        }
+
+        @Override
+        public boolean equals(Object obj) {
+            if (this == obj) {
+                return true;
+            }
+            if (!(obj instanceof E)) {
+                return false;
+            }
+            E other = (E) obj;
+            return Objects.equals(referenceToA, other.referenceToA);
+        }
+    }
+}