DATAMONGO-2314 - Fix query by example on nested properties.

This fix allows using alike on nested properties.

new Criteria("nested").alike(Example.of(probe, matching().withIgnorePaths("_class"))));

Switch tests to AssertJ.

Original pull request: #771.

Author: christophstrobl

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/QueryMapper.java

@@ -307,16 +307,19 @@ protected Document getMappedKeyword(Field property, Keyword keyword) {
 		Object convertedValue = needsAssociationConversion ? convertAssociation(value, property)
 				: getMappedValue(property.with(keyword.getKey()), value);
 
+		if(keyword.isSample() && convertedValue instanceof Document) {
+			return (Document) convertedValue;
+		}
+
 		return new Document(keyword.key, convertedValue);
 	}
 
 	/**
 	 * Returns the mapped value for the given source object assuming it's a value for the given
 	 * {@link MongoPersistentProperty}.
 	 *
+	 * @param documentField the key the value will be bound to eventually
 	 * @param value the source object to be mapped
-	 * @param property the property the value is a value for
-	 * @param newKey the key the value will be bound to eventually
 	 * @return
 	 */
 	@Nullable
@@ -423,6 +426,10 @@ protected boolean isAssociationConversionNecessary(Field documentField, @Nullabl
 	@SuppressWarnings("unchecked")
 	protected Object convertSimpleOrDocument(Object source, @Nullable MongoPersistentEntity<?> entity) {
 
+		if(source instanceof Example) {
+			return exampleMapper.getMappedExample((Example)source, entity);
+		}
+
 		if (source instanceof List) {
 			return delegateConvertToMongoType(source, entity);
 		}

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/query/Criteria.java

@@ -597,7 +597,6 @@ public Criteria elemMatch(Criteria c) {
 	public Criteria alike(Example<?> sample) {
 
 		criteria.put("$example", sample);
-		this.criteriaChain.add(this);
 		return this;
 	}
 

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/QueryByExampleTests.java

@@ -15,13 +15,11 @@
  */
 package org.springframework.data.mongodb.core;
 
-import static org.hamcrest.Matchers.*;
-import static org.junit.Assert.*;
+import static org.assertj.core.api.Assertions.*;
 
 import lombok.EqualsAndHashCode;
 import lombok.ToString;
 
-import java.net.UnknownHostException;
 import java.util.List;
 
 import org.junit.Before;
@@ -50,7 +48,7 @@ public class QueryByExampleTests {
 	Person p1, p2, p3;
 
 	@Before
-	public void setUp() throws UnknownHostException {
+	public void setUp() {
 
 		operations = new MongoTemplate(new MongoClient(), "query-by-example");
 		operations.remove(new Query(), Person.class);
@@ -82,8 +80,7 @@ public void findByExampleShouldWorkForSimpleProperty() {
 		Query query = new Query(new Criteria().alike(Example.of(sample)));
 		List<Person> result = operations.find(query, Person.class);
 
-		assertThat(result, hasSize(2));
-		assertThat(result, hasItems(p1, p3));
+		assertThat(result).containsExactlyInAnyOrder(p1, p3);
 	}
 
 	@Test // DATAMONGO-1245
@@ -96,8 +93,7 @@ public void findByExampleShouldWorkForMultipleProperties() {
 		Query query = new Query(new Criteria().alike(Example.of(sample)));
 		List<Person> result = operations.find(query, Person.class);
 
-		assertThat(result, hasSize(1));
-		assertThat(result, hasItem(p3));
+		assertThat(result).containsExactly(p3);
 	}
 
 	@Test // DATAMONGO-1245
@@ -112,8 +108,7 @@ public void findByExampleShouldWorkForIdProperty() {
 		Query query = new Query(new Criteria().alike(Example.of(sample)));
 		List<Person> result = operations.find(query, Person.class);
 
-		assertThat(result, hasSize(1));
-		assertThat(result, hasItem(p4));
+		assertThat(result).containsExactly(p4);
 	}
 
 	@Test // DATAMONGO-1245
@@ -126,7 +121,7 @@ public void findByExampleShouldReturnEmptyListIfNotMatching() {
 		Query query = new Query(new Criteria().alike(Example.of(sample)));
 		List<Person> result = operations.find(query, Person.class);
 
-		assertThat(result, is(empty()));
+		assertThat(result).isEmpty();
 	}
 
 	@Test // DATAMONGO-1245
@@ -137,8 +132,7 @@ public void findByExampleShouldReturnEverythingWhenSampleIsEmpty() {
 		Query query = new Query(new Criteria().alike(Example.of(sample)));
 		List<Person> result = operations.find(query, Person.class);
 
-		assertThat(result, hasSize(3));
-		assertThat(result, hasItems(p1, p2, p3));
+		assertThat(result).containsExactlyInAnyOrder(p1, p2, p3);
 	}
 
 	@Test // DATAMONGO-1245
@@ -150,7 +144,7 @@ public void findByExampleWithCriteria() {
 		Query query = new Query(new Criteria().alike(Example.of(sample)).and("firstname").regex("^ary*"));
 
 		List<Person> result = operations.find(query, Person.class);
-		assertThat(result.size(), is(1));
+		assertThat(result).hasSize(1);
 	}
 
 	@Test // DATAMONGO-1459
@@ -163,8 +157,7 @@ public void findsExampleUsingAnyMatch() {
 		Query query = Query.query(Criteria.byExample(Example.of(probe, ExampleMatcher.matchingAny())));
 		List<Person> result = operations.find(query, Person.class);
 
-		assertThat(result, hasSize(2));
-		assertThat(result, hasItems(p1, p2));
+		assertThat(result).containsExactlyInAnyOrder(p1, p2);
 	}
 
 	@Test // DATAMONGO-1768
@@ -176,7 +169,7 @@ public void typedExampleMatchesNothingIfTypesDoNotMatch() {
 		Query query = new Query(new Criteria().alike(Example.of(probe)));
 		List<Person> result = operations.find(query, Person.class);
 
-		assertThat(result, hasSize(0));
+		assertThat(result).isEmpty();
 	}
 
 	@Test // DATAMONGO-1768
@@ -189,8 +182,7 @@ public void exampleIgnoringClassTypeKeyMatchesCorrectly() {
 				new Criteria().alike(Example.of(probe, ExampleMatcher.matching().withIgnorePaths("_class"))));
 		List<Person> result = operations.find(query, Person.class);
 
-		assertThat(result, hasSize(2));
-		assertThat(result, hasItems(p1, p3));
+		assertThat(result).containsExactlyInAnyOrder(p1, p3);
 	}
 
 	@Test // DATAMONGO-1768
@@ -202,8 +194,28 @@ public void untypedExampleMatchesCorrectly() {
 		Query query = new Query(new Criteria().alike(Example.of(probe, UntypedExampleMatcher.matching())));
 		List<Person> result = operations.find(query, Person.class);
 
-		assertThat(result, hasSize(2));
-		assertThat(result, hasItems(p1, p3));
+		assertThat(result).containsExactlyInAnyOrder(p1, p3);
+	}
+
+	@Test // DATAMONGO-2314
+	public void alikeShouldWorkOnNestedProperties() {
+
+		PersonWrapper source1 = new PersonWrapper();
+		source1.id = "with-child-doc-1";
+		source1.child = p1;
+
+		PersonWrapper source2 = new PersonWrapper();
+		source2.id = "with-child-doc-2";
+		source2.child = p2;
+
+		operations.save(source1);
+		operations.save(source2);
+
+		Query query = new Query(
+				new Criteria("child").alike(Example.of(p1, ExampleMatcher.matching().withIgnorePaths("_class"))));
+		List<PersonWrapper> result = operations.find(query, PersonWrapper.class);
+
+		assertThat(result).containsExactly(source1);
 	}
 
 	@Document("dramatis-personae")
@@ -223,4 +235,13 @@ static class NotAPersonButStillMatchingFields {
 		String firstname, middlename;
 		@Field("last_name") String lastname;
 	}
+
+	@Document("dramatis-personae")
+	@EqualsAndHashCode
+	@ToString
+	static class PersonWrapper {
+
+		@Id String id;
+		Person child;
+	}
 }