Fix "is-a" ValueSet expansion and add "descendent-of" support

[ohetrifork]

Hi,

We're implementing validation for an custom implementation guide (IG) using HAPI FHIR. The IG contain ValueSets that are defined using "descendent-of" and "is-a" relations, using codes from a custom code system. To that end, we have identified a couple of issues with the HAPI FHIR ValueSet expansion:

1. The existing implementation of "is-a" (see

   hapi-fhir/hapi-fhir-jpaserver-base/src/main/java/ca/uhn/fhir/jpa/term/TermReadSvcImpl.java

   Line 1595 in 9e20659

   b.must(f.match().field("myParentPids").matching("" + code.getId()));

   ) is not correct. The validation rejects the actual code pointed to by the "is-a" definition although is should be allowed (along with its "child nodes" for that code). Actually, this is a correct implementation of the "descendent-of", which does not include the actual "root node" being pointed to. For definitions of "is-a" and "descendent-of" see https://build.fhir.org/valueset-filter-operator.html
2. For ValueSet expansion "descendent-of" is not supported. When ValueSet expansion runs, the error "HAPI-0894: Don't know how to handle op=DESCENDENTOF on property concept" happens.

So far we have solved the problem locally using a classpath override of the TermReadSvcImpl class, but we would like to avoid that going forward.

[tadgh]

Looks good to me. Going to have a few more people internally have a look, but its likely we can get this merged for 7.0.0. Can you please re-target this MR to rel_7_0 branch?

[tadgh]

Failures here:

12:45:15,091 [ERROR] Failures: 
12:45:15,091 [ERROR]   FhirResourceDaoDstu3TerminologyTest.testExpandWithIsAInExternalValueSet:507 
Expected: iterable with items ["childAA", "childAAA", "childAAB"] in any order
     but: no item matches: "childAA" in ["childAAA", "childAAB"]
12:45:15,091 [ERROR]   FhirResourceDaoDstu3TerminologyTest.testExpandWithIsAInExternalValueSetReindex:538 
Expected: iterable with items ["childAA", "childAAA", "childAAB"] in any order
     but: no item matches: "childAA" in ["childAAA", "childAAB"]
12:45:15,091 [ERROR] Errors: 
12:45:15,091 [ERROR]   FhirResourceDaoDstu3TerminologyTest.testExpandWithCodesAndDisplayFilterBlank:321 » InvalidRequest HAPI-0894: Don't know how to handle op=DESCENDENTOF on property concept
12:45:15,091 [ERROR]   FhirResourceDaoDstu3TerminologyTest.testIndexingIsDeferredForLargeCodeSystems:655 » InvalidRequest HAPI-0894: Don't know how to handle op=DESCENDENTOF on property concept
12:45:15,091 [ERROR]   ResourceProviderCustomSearchParamDstu3Test.testCreatingParamMarksCorrectResourcesForReindexing:204->BaseJpaTest.runInTransaction:591->lambda$testCreatingParamMarksCorrectResourcesForReindexing$0:205 » CannotCreateTransaction Could not open JPA EntityManager for transaction
12:45:15,091 [ERROR]   ResourceProviderDstu3ValueSetVersionedTest.testExpandInlineVsAgainstExternalCs:810 » InvalidRequest HTTP 400 Bad Request: HAPI-0894: Don't know how to handle op=DESCENDENTOF on property concept
12:45:15,091 [ERROR]   ResourceProviderDstu3ValueSetVersionedTest.testExpandLocalVsAgainstExternalCs:850 » InvalidRequest HTTP 400 Bad Request: HAPI-0894: Don't know how to handle op=DESCENDENTOF on property concept
12:45:15,091 [ERROR]   ResourceProviderDstu3ValueSetVersionedTest.testExpandLocalVsCanonicalAgainstExternalCs:889 » InvalidRequest HTTP 400 Bad Request: HAPI-0894: Don't know how to handle op=DESCENDENTOF on property concept
12:45:15,091 [INFO] 

[tadgh]

@ohetrifork I have cloned your work and made a repo-local copy(#5669) just for ease of merging as i deal with conflicts and spotless resolution. I have also attributed you in the changelog, and in our developers section. Please let me know if you do not want this, and I can remove your attribution. Otherwise I will get this merged ASAP

[tadgh]

Closing this as the other has merged.

[ohetrifork]

Cool @tadgh, thanks for helping out