History returns items in the wrong order

[rmeoc]

Describe the bug
The versions returned when retrieving history are sorted from old to new, while they should be from new to old. See the following section of the FHIR Specification (from http://hl7.org/fhir/http.html#history):

The return content is a Bundle with type set to history containing the specified version history, sorted with oldest versions last, and including deleted resources.

FHIR Version?
Stu3

Data provider?
I don't know. I have encountered the bug with the Azure Health Data Services FHIR service. I don't know what Data provider is used by that service.

To Reproduce
Steps to reproduce the behavior:

1. Invoke the history interaction, e.g. GET [base]/[type]/[id]/_history

Expected behavior
A bundle is returned containing the version history sorted with oldest versions last.

Actual behavior
A bundle is returned containing the version history sorted with oldest versions first.

AB#93193

[brendankowitz]

Hi @rmeoc, thanks for reporting this, we'll investigate

[brendankowitz]

Cosmos sorts correctly with _lastUpdated DESC:

fhir-server/src/Microsoft.Health.Fhir.CosmosDb/Features/Search/Queries/QueryBuilder.cs

Lines 142 to 147 in 4cfd7aa

	_queryBuilder
	.Append("ORDER BY ")
	#pragma warning disable CA1834 // Consider using 'StringBuilder.Append(char)' when applicable
	.Append(SearchValueConstants.RootAliasName).Append('.').Append(KnownResourceWrapperProperties.LastModified)
	#pragma warning restore CA1834 // Consider using 'StringBuilder.Append(char)' when applicable
	.AppendLine(" DESC");

The SQL Provider looks to be sorting incorrectly with:

fhir-server/src/Microsoft.Health.Fhir.SqlServer/Features/Search/SqlServerSearchService.cs

Lines 491 to 494 in 4cfd7aa

	newSearchOptions.Sort = new (SearchParameterInfo searchParameterInfo, SortOrder sortOrder)[]
	{
	(_fakeLastUpdate, SortOrder.Ascending),
	};

History tests should be updated to check ordering:

fhir-server/test/Microsoft.Health.Fhir.Shared.Tests.E2E/Rest/HistoryTests.cs

Lines 86 to 93 in 4cfd7aa

	[Fact]
	[Trait(Traits.Priority, Priority.One)]
	public async Task GivenNoType_WhenGettingSystemHistory_TheServerShouldReturnTheAppropriateBundleSuccessfully()
	{
	using FhirResponse<Bundle> readResponse = await _client.SearchAsync("_history");
	Assert.NotEmpty(readResponse.Resource.Entry);
	}

[EXPEkesheth]

@rmeoc Thanks for reporting the issue. The issue is fixed.
Reach out for any additional questions.