From ca0af58ddd9f4427a2271d36fcf5bb5afbf93315 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Luk=C3=A1=C5=A1=20Ka=C5=88ka?= <kankaluk@fel.cvut.cz>
Date: Thu, 14 Nov 2024 15:07:34 +0100
Subject: [PATCH] [Enhancement kbss-cvut/termit-ui#528] Change
 TermDao#resolveVocabularyId to return optional URI instead of throwing when
 term is not found (not in a vocabulary).

---
 .../cz/cvut/kbss/termit/persistence/dao/TermDao.java | 12 ++++++------
 .../kbss/termit/persistence/dao/TermDaoTest.java     |  9 +++++++++
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/src/main/java/cz/cvut/kbss/termit/persistence/dao/TermDao.java b/src/main/java/cz/cvut/kbss/termit/persistence/dao/TermDao.java
index 052035b25..47180aa51 100644
--- a/src/main/java/cz/cvut/kbss/termit/persistence/dao/TermDao.java
+++ b/src/main/java/cz/cvut/kbss/termit/persistence/dao/TermDao.java
@@ -91,8 +91,8 @@ protected URI labelProperty() {
     @Override
     public Optional<Term> find(URI id) {
         try {
-            final Optional<Term> result = Optional.ofNullable(
-                    em.find(Term.class, id, descriptorFactory.termDescriptor(resolveVocabularyId(id))));
+            final Optional<Term> result = resolveVocabularyId(id).map(vocabulary ->
+                    em.find(Term.class, id, descriptorFactory.termDescriptor(vocabulary)));
             result.ifPresent(this::postLoad);
             return result;
         } catch (RuntimeException e) {
@@ -100,14 +100,14 @@ public Optional<Term> find(URI id) {
         }
     }
 
-    private URI resolveVocabularyId(URI termId) {
+    private Optional<URI> resolveVocabularyId(URI termId) {
         try {
-            return em.createNativeQuery("SELECT DISTINCT ?v WHERE { ?t ?inVocabulary ?v . }", URI.class)
+            return Optional.of(em.createNativeQuery("SELECT DISTINCT ?v WHERE { ?t ?inVocabulary ?v . }", URI.class)
                      .setParameter("t", termId)
                      .setParameter("inVocabulary", TERM_FROM_VOCABULARY)
-                     .getSingleResult();
+                     .getSingleResult());
         } catch (NoResultException | NoUniqueResultException e) {
-            throw new PersistenceException("Unable to resolve term vocabulary.", e);
+            return Optional.empty();
         }
     }
 
diff --git a/src/test/java/cz/cvut/kbss/termit/persistence/dao/TermDaoTest.java b/src/test/java/cz/cvut/kbss/termit/persistence/dao/TermDaoTest.java
index 036c8bcf4..75ac29892 100644
--- a/src/test/java/cz/cvut/kbss/termit/persistence/dao/TermDaoTest.java
+++ b/src/test/java/cz/cvut/kbss/termit/persistence/dao/TermDaoTest.java
@@ -82,6 +82,7 @@
 import static org.hamcrest.Matchers.lessThan;
 import static org.hamcrest.Matchers.not;
 import static org.hamcrest.Matchers.nullValue;
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertInstanceOf;
@@ -1394,4 +1395,12 @@ void findByIdLoadsTermFromVocabularyContextOnly() {
         assertTrue(result.isPresent());
         assertFalse(result.get().getProperties().containsKey(property));
     }
+
+    @Test
+    void findByIdReturnsOptionalEmptyWhenTermDoesNotExists() {
+        final Term term = Generator.generateTermWithId(vocabulary.getUri());
+        // trying to find a non-existing term
+        final Optional<Term> empty = assertDoesNotThrow(()-> sut.find(term.getUri()));
+        assertTrue(empty.isEmpty());
+    }
 }