ResourceFingerprintVisitor fails to account for integer values

[lmsurpre]

Describe the bug
I found that the ResourceFingerprintVisitor is failing to add integer values to its digest.

Environment
main

To Reproduce

    @Test
    public void testUnequalResources_intVals() throws Exception {
        Patient patient = TestUtil.getMinimalResource(Patient.class).toBuilder()
                .multipleBirth(1)
                .build();

        ResourceFingerprintVisitor resourceFingerprintVisitor = new ResourceFingerprintVisitor();
        patient.accept(resourceFingerprintVisitor);
        SaltHash baseline = resourceFingerprintVisitor.getSaltAndHash();

        patient = patient.toBuilder()
                .multipleBirth(2)
                .build();
        resourceFingerprintVisitor = new ResourceFingerprintVisitor(baseline);
        patient.accept(resourceFingerprintVisitor);
        assertNotEquals(resourceFingerprintVisitor.getSaltAndHash(), baseline);
    }

Expected behavior
the test should succeed

Additional context
does the ByteBuffer need to get flipped before we add it to the digest?

    @Override
    public void visit(java.lang.String elementName, java.lang.Integer value) {
        ByteBuffer bb = ByteBuffer.allocate(4);
        bb.putInt(value);
        // flip here?
        digest.update(bb);
    }

[punktilious]

Defined a new extension search parameter:

{
    "resourceType": "Bundle",
    "type": "collection",
    "entry": [
                    {
                "fullUrl": "http://ibm.com/fhir/SearchParameter/Basic-favorite-number",
                "resource": {
                        "resourceType": "SearchParameter",
                        "id": "Basic-favorite-number",
                        "url": "http://ibm.com/fhir/SearchParameter/Basic-favorite-number",
                        "version": "4.0.0",
                        "name": "favorite-number",
                        "status": "draft",
                        "experimental": false,
                        "date": "2018-12-27T22:37:54+11:00",
                        "publisher": "IBM FHIR Server Test",
                        "contact": [{
                                "telecom": [{
                                        "system": "url",
                                        "value": "http://ibm.com/fhir"
                                }]
                        },
                        {
                                "telecom": [{
                                        "system": "url",
                                        "value": "http://ibm.com/fhir"
                                }]
                        }],
                        "description": "the patient's favorite number",
                        "code": "favorite-number",
                        "base": ["Basic"],
                        "type": "number",
                        "xpathUsage": "normal",
                        "xpath": "f:Basic/f:extension[@url='http://ibm.com/fhir/extension/Basic/favorite-number']/f:valueInteger",
                        "expression": "Basic.extension.where(url='http://ibm.com/fhir/extension/Basic/favorite-number').value.as(Integer)",
                        "multipleOr": true,
                        "multipleAnd": true,
                        "modifier": []
                }
        }
    ]
}

Create an instance of the resource:

{
  "resourceType": "Basic",
  "id": "basic1",
  "code": {
    "text": "test"
  },
  "extension": [
    {
      "url": "http://ibm.com/fhir/extension/Basic/favorite-number",
      "valueInteger": 12
    },
    {
      "url": "http://ibm.com/fhir/extension/Basic/favorite-decimal",
      "valueDecimal": 99.99
    },
    {
      "url": "http://ibm.com/fhir/extension/Basic/favorite-boolean",
      "valueBoolean": true
    },
    {
      "url": "http://ibm.com/fhir/extension/Basic/favorite-precision",
      "valueDecimal": 100.25
    }
  ]
}

Inspect the database to see the current parameter_hash value:

fhirdb=> select * from fhirdata.logical_resources where logical_id = 'basic1';
fhirdb=> select * from fhirdata.logical_resources where logical_id = 'basic1';
 logical_resource_id | resource_type_id | logical_id |   reindex_tstamp    | reindex_txid |        last_updated        | is_deleted |                parameter_hash                
---------------------+------------------+------------+---------------------+--------------+----------------------------+------------+----------------------------------------------
            85745130 |                8 | basic1     | 1970-01-01 00:00:00 |            0 | 2022-08-07 21:44:31.124855 | N          | L47pUAnksDJO9VVp8Ey00DP1gFgoMqzdfNdcOvYI0zQ=

And the stored search parameter value should be 12

fhirdb=> select * from fhirdata.basic_number_values where logical_resource_id = 85745130;
 parameter_name_id | number_value | logical_resource_id | number_value_low | number_value_high | composite_id 
-------------------+--------------+---------------------+------------------+-------------------+--------------
            239000 |           12 |            85745130 |               12 |                12 |             

Next UPDATE the resource using a different integer value then inspect the database:

fhirdb=> select * from fhirdata.logical_resources where logical_id = 'basic1';
 logical_resource_id | resource_type_id | logical_id |   reindex_tstamp    | reindex_txid |        last_updated        | is_deleted |                parameter_hash                
---------------------+------------------+------------+---------------------+--------------+----------------------------+------------+----------------------------------------------
            85745130 |                8 | basic1     | 1970-01-01 00:00:00 |            0 | 2022-08-07 21:45:15.992466 | N          | z2jgGWiFiBTOFTV94cJlUTxSksI4T2zhJlfU0PdqKao=
(1 row)

fhirdb=> select * from fhirdata.basic_number_values where logical_resource_id = 85745130;
 parameter_name_id | number_value | logical_resource_id | number_value_low | number_value_high | composite_id 
-------------------+--------------+---------------------+------------------+-------------------+--------------
            239000 |           42 |            85745130 |               42 |                42 |             

Note the new value is stored and the parameter_hash is different, as expected.

[punktilious]

Reviewed above with Lee and agreed we can close this.