Fixes incorrect error with multiple permitted subtypes for sealed type

CHANGELOG.md

@@ -13,6 +13,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- Fixes incorrect error message when a sealed type has multiple permitted subtypes. ([Issue 786](https://github.com/jqno/equalsverifier/issues/786))
+
 ## [3.14] - 2023-02-27
 
 ### Added

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

@@ -64,6 +64,16 @@ public void fail_whenSealeadParentHasAnIncorrectImplementationOfEquals() {
             .assertFailure();
     }
 
+    @Test
+    void succeed_whenSealedParentHasTwoChildren_a() {
+        EqualsVerifier.forClass(SealedChildA.class).verify();
+    }
+
+    @Test
+    void succeed_whenSealedParentHasTwoChildren_b() {
+        EqualsVerifier.forClass(SealedChildB.class).verify();
+    }
+
     public abstract static sealed class SealedParentWithFinalChild permits FinalSealedChild {
 
         private final int i;
@@ -196,4 +206,46 @@ public IncorrectSealedChild(int i) {
             super(i);
         }
     }
+
+    public abstract static sealed class SealedParentWithTwoChildren {
+
+        final String value;
+
+        protected SealedParentWithTwoChildren(String value) {
+            this.value = value;
+        }
+
+        @Override
+        public boolean equals(Object other) {
+            return (
+                other != null &&
+                (this.getClass() == other.getClass()) &&
+                Objects.equals(this.value, ((SealedParentWithTwoChildren) other).value)
+            );
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hashCode(this.value);
+        }
+
+        @Override
+        public String toString() {
+            return getClass().getSimpleName() + " '" + value + "'";
+        }
+    }
+
+    public static final class SealedChildA extends SealedParentWithTwoChildren {
+
+        SealedChildA(String value) {
+            super(value);
+        }
+    }
+
+    public static final class SealedChildB extends SealedParentWithTwoChildren {
+
+        SealedChildB(String value) {
+            super(value);
+        }
+    }
 }

equalsverifier-core/src/main/java/nl/jqno/equalsverifier/internal/checkers/HierarchyChecker.java

@@ -62,7 +62,7 @@ public void check() {
 
     private void checkSuperclass() {
         ClassAccessor<? super T> superAccessor = classAccessor.getSuperAccessor();
-        if (superAccessor.isEqualsInheritedFromObject()) {
+        if (superAccessor.isEqualsInheritedFromObject() || superAccessor.isSealed()) {
             return;
         }