DATAREST-1356 - Fix for a bug around single link PUTs introduced in 554d6cb2

[bvulaj]

Fix for the change:

-				if (source.getLinks().size() != 1) {
+				if (source.getLinks().hasSingleLink()) {

554d6cb#diff-1d7c16fe1992fef13a47fa8ab8599718L317

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[bvulaj]

This is still a bug in 3.2 RC - any update on merging?

[lareferencia]

Sorry, but I am having problems with this issue.

Correct me if am wrong, but in line 321, the context is "check if is a single link since we are updating a property that is not a collection" so I think that the right line is

if ( ! source.getLinks().hasSingleLink() ) {
note the !

because the exception only must be throw if links is greater than 1

[gregturn]

Is there a test case that illustrates this? We can't move forward on a single line change that flips on a "!".

[lareferencia]

Sorry, I just discovered a pull request with the same proposal waiting to be approved.

#364

[bvulaj]

#364 is a duplicate of this PR.

[luvarqpp]

Try to have a look at git blame just before bug was introduced: https://github.com/spring-projects/spring-data-rest/blame/ce321da80715f9201a5fa12b4385264e3e861c31/spring-data-rest-webmvc/src/main/java/org/springframework/data/rest/webmvc/RepositoryPropertyReferenceController.java#L317

To test this problem (I would write some, having a time to learn how to make some unit test instead of integration one):

• prepare entity Comment with OneToOne association to User (createdBy association)
• prepare User entity
• try to associate some author to existing Comment

Sample code snippet for last step:

createCommentResponse = ...
userLink = ...

final String authorAssociationEndpoint = JsonPath.read(createCommentResponse.getResponseBody(), "$._links.createdBy.href");
log.info("Going to add single User to association endpoint for author (createdBy).");
        this.webClient.put().uri(authorAssociationEndpoint)
                .contentType(MediaType.valueOf("text/uri-list"))
                .accept(MediaTypes.HAL_JSON)
                .bodyValue(userLink)
                .exchange().expectStatus().value(is(204));

PS: If someone can point me to similar test, I will try to implement this one.

[lqforgithub]

if you are using spring boot 2.2.0.RELEASE, you'll have this bug. 2.1.4.RELEASE is fine.

[luvarqpp]

Is there a test case that illustrates this? We can't move forward on a single line change that flips on a "!".

I have created two tests. One positive and one negative. It is in my version of pull request #364 to this bug.

[gregturn]

Resolved via 202a8aa. Backported to 3.2.x via 87f9904.

Thanks everyone for working hard to bring this one home. I went ahead and used #364 as the final solution.

The solution is in both master branch (Neumann) as well as 3.2.x (Moore SR1).