Merge pull request #770 from KyleAure/607-jsonbtypeadapter-records

test: jsonb type adapater on records

src/test/java/org/eclipse/yasson/records/RecordTest.java

diff --git a/src/test/java/org/eclipse/yasson/records/RecordTest.java b/src/test/java/org/eclipse/yasson/records/RecordTest.java
index 526b0d0..813120d 100644
--- a/src/test/java/org/eclipse/yasson/records/RecordTest.java
+++ b/src/test/java/org/eclipse/yasson/records/RecordTest.java
@@ -21,6 +21,8 @@
 import org.eclipse.yasson.internal.properties.Messages;
 import org.junit.jupiter.api.Test;
 
+import java.util.Set;
+
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.containsString;
 import static org.hamcrest.Matchers.is;
@@ -208,4 +210,31 @@
         assertThat(json, containsString("\"getDisplayName\":\"skoda (green)\""));
         assertThat(json, not(containsString("\"displayName\"")));
     }
+
+    // -----------------------------------------------------------------
+    // Issue #607 — @JsonbTypeAdapter on record components
+    // -----------------------------------------------------------------
+
+    /**
+     * Serialising a record whose component is annotated with {@code @JsonbTypeAdapter}
+     * must invoke the adapter and produce the adapted JSON value.
+     */
+    @Test
+    public void testRecordWithTypeAdapterSerialisation() {
+        RecordWithTypeAdapter record = new RecordWithTypeAdapter(Set.of("b", "a", "c"));
+        // SetToStringAdapter.adaptToJson sorts entries before joining
+        String json = Jsonbs.defaultJsonb.toJson(record);
+        assertThat(json, is("{\"entries\":\"a,b,c\"}"));
+    }
+
+    /**
+     * Deserialising into a record whose component is annotated with {@code @JsonbTypeAdapter}
+     * must invoke the adapter and reconstruct the original collection value.
+     */
+    @Test
+    public void testRecordWithTypeAdapterDeserialisation() {
+        String json = "{\"entries\":\"a,b,c\"}";
+        RecordWithTypeAdapter record = Jsonbs.defaultJsonb.fromJson(json, RecordWithTypeAdapter.class);
+        assertThat(record.entries(), is(Set.of("a", "b", "c")));
+    }
 }

src/test/java/org/eclipse/yasson/records/RecordWithTypeAdapter.java

diff --git a/src/test/java/org/eclipse/yasson/records/RecordWithTypeAdapter.java b/src/test/java/org/eclipse/yasson/records/RecordWithTypeAdapter.java
new file mode 100644
index 0000000..5b90e78
--- /dev/null
+++ b/src/test/java/org/eclipse/yasson/records/RecordWithTypeAdapter.java
@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2026 Contributors to the Eclipse Foundation
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0,
+ * or the Eclipse Distribution License v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ */
+
+package org.eclipse.yasson.records;
+
+import jakarta.json.bind.annotation.JsonbProperty;
+import jakarta.json.bind.annotation.JsonbTypeAdapter;
+
+import java.util.Set;
+
+/**
+ * Reproducer record for issue #607: {@code @JsonbTypeAdapter} annotated on a record component
+ * must be recognised and applied during both serialisation and deserialisation.
+ */
+public record RecordWithTypeAdapter(
+        @JsonbProperty("entries")
+        @JsonbTypeAdapter(SetToStringAdapter.class)
+        Set<String> entries) {
+}

src/test/java/org/eclipse/yasson/records/SetToStringAdapter.java

diff --git a/src/test/java/org/eclipse/yasson/records/SetToStringAdapter.java b/src/test/java/org/eclipse/yasson/records/SetToStringAdapter.java
new file mode 100644
index 0000000..ceb453d
--- /dev/null
+++ b/src/test/java/org/eclipse/yasson/records/SetToStringAdapter.java
@@ -0,0 +1,39 @@
+/*
+ * Copyright (c) 2026 Contributors to the Eclipse Foundation
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0,
+ * or the Eclipse Distribution License v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ */
+
+package org.eclipse.yasson.records;
+
+import jakarta.json.bind.adapter.JsonbAdapter;
+
+import java.util.Arrays;
+import java.util.LinkedHashSet;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+/**
+ * Adapter used to reproduce issue #607: {@code @JsonbTypeAdapter} on a record component
+ * must be recognised and invoked for both serialisation and deserialisation.
+ * <p>
+ * Converts a {@code Set<String>} to/from a comma-separated {@code String}.
+ */
+public class SetToStringAdapter implements JsonbAdapter<Set<String>, String> {
+
+    @Override
+    public String adaptToJson(Set<String> obj) {
+        return obj.stream().sorted().collect(Collectors.joining(","));
+    }
+
+    @Override
+    public Set<String> adaptFromJson(String obj) {
+        return new LinkedHashSet<>(Arrays.asList(obj.split(",")));
+    }
+}