Fix 176 Add the ability to choose the join type with ElementCollection (perplexhub#179)

Author: jfb-NRB

rsql-jpa/src/main/java/io/github/perplexhub/rsql/RSQLJPAPredicateConverter.java

@@ -144,7 +144,7 @@ private RSQLJPAContext findPropertyPathInternal(String propertyPath, Path startR
 					classMetadata = getManagedElementCollectionType(mappedProperty, classMetadata);
 					String keyJoin = getKeyJoin(root, mappedProperty);
 					log.debug("Create a element collection join between [{}] and [{}] using key [{}]", previousClass, classMetadata.getJavaType().getName(), keyJoin);
-					root = join(keyJoin, root, mappedProperty);
+					root = join(keyJoin, root, mappedProperty, joinHints.get(keyJoin));
 				} else if (JsonbSupport.isJsonType(mappedProperty, classMetadata)) {
 					root = root.get(mappedProperty);
 					attribute = RSQLVisitorBase.getAttribute(mappedProperty, classMetadata);

rsql-jpa/src/test/java/io/github/perplexhub/rsql/RSQLJPASupportTest.java

@@ -278,6 +278,26 @@ final void testElementCollection2() {
 		assertThat(rsql, count, is(4L));
 	}
 
+	@Test
+	final void testElementCollection1WithJoinHints() {
+		final Map<String, JoinType> joinHints = Map.of("Company.tags", JoinType.LEFT);
+		final String rsql = "tags!=tech,tags=na=";
+		final List<Company> companies = companyRepository.findAll(toSpecification(rsql, null, joinHints));
+		final long count = companies.size();
+		log.info("rsql: {} -> count: {}", rsql, count);
+		assertThat(rsql, count, is(4L));
+	}
+
+	@Test
+	final void testElementCollection2WithJoinHints() {
+		final Map<String, JoinType> joinHints = Map.of("Company.bigTags", JoinType.LEFT);
+		final String rsql = "bigTags.tag!=tech,bigTags.tag=na=";
+		final List<Company> companies = companyRepository.findAll(toSpecification(rsql, null, joinHints));
+		final long count = companies.size();
+		log.info("rsql: {} -> count: {}", rsql, count);
+		assertThat(rsql, count, is(4L));
+	}
+
 	@Test
 	final void testToComplexMultiValueMap() {
 		String rsql = "sites.trunks.id==2,id=na=2,company.id=='2',id=na=3,name==''";