JPA @ManyToMany associated entity not returned in json results [DATAREST-795]

coolnodje opened DATAREST-795 and commented

When using a SampleRepository for a Sample entity, the @ManyToMany mapping doesn't appear in the return json when querying instance of Sample.

The mapping in Sample entity:
@ManyToMany(fetch = FetchType.EAGER)
@JoinTable(
name = "SAMPLE_AUTHORITY_INDEX",
joinColumns = {@JoinColumn(name = "sample_id", referencedColumnName = "id")},
inverseJoinColumns = {@JoinColumn(name = "authority_label", referencedColumnName = "label")})
private Set<Authority> authorities = new HashSet<>();

The Sample#1 has an authority called LABEL1 which won't show up when querying the rest-data api:

curl http://localhost:8080/samples/1
{
"name" : "john",
"authorities" : [ { } ],
"link" : {
"self" : {
"href" : "http://localhost:8080/samples/1"
},
"sample" : {
"href" : "http://localhost:8080/samples/1"
}
}
}
The equivalent :
curl http://localhost:8080/samples/search/findByName?name=john
{
"name" : "john",
"authorities" : [ { } ],
"link" : {
"self" : {
"href" : "http://localhost:8080/samples/1"
},
"sample" : {
"href" : "http://localhost:8080/samples/1"
}
}
}%

also return empty authorities.

Though when implementing my own endpoint calling the above mentioned 'findByName' on SampleRepository, I get the authority content:

curl http://localhost:8080/v1/find/john
{"id":1,"name":"john","authorities":[{"label":"LABEL1"}]}%

Looking at the controller that handles the request, RepositorySearchController.java on executeSearch(...) method on line 174 contains the authority collection when it return new ResponseEntity(...) on line 185. I don't understand what happens after that and why the collection content doesn't make it to the json output

Affects: 2.4.4 (Gosling SR4)