From dc89a4abd7271c820ff86dcf5ff1e0d78e3333dc Mon Sep 17 00:00:00 2001
From: Nick Goupinets <nick.goupinets@smilecdr.com>
Date: Wed, 26 May 2021 15:13:43 -0400
Subject: [PATCH] Updated identifier matcher to only match on non-empty values

---
 .../fhir/mdm/rules/matcher/IdentifierMatcher.java    | 12 +++++++++++-
 .../mdm/rules/matcher/IdentifierMatcherR4Test.java   | 11 +++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/hapi-fhir-server-mdm/src/main/java/ca/uhn/fhir/mdm/rules/matcher/IdentifierMatcher.java b/hapi-fhir-server-mdm/src/main/java/ca/uhn/fhir/mdm/rules/matcher/IdentifierMatcher.java
index 40fcc4fe03d..66dcf389b8a 100644
--- a/hapi-fhir-server-mdm/src/main/java/ca/uhn/fhir/mdm/rules/matcher/IdentifierMatcher.java
+++ b/hapi-fhir-server-mdm/src/main/java/ca/uhn/fhir/mdm/rules/matcher/IdentifierMatcher.java
@@ -23,11 +23,11 @@ package ca.uhn.fhir.mdm.rules.matcher;
 import ca.uhn.fhir.context.FhirContext;
 import ca.uhn.fhir.mdm.util.CanonicalIdentifier;
 import ca.uhn.fhir.mdm.util.IdentifierUtil;
+import ca.uhn.fhir.model.primitive.StringDt;
 import org.hl7.fhir.instance.model.api.IBase;
 
 public class IdentifierMatcher implements IMdmFieldMatcher {
 	/**
-	 *
 	 * @return true if the two fhir identifiers are the same.  If @param theIdentifierSystem is not null, then the
 	 * matcher only returns true if the identifier systems also match this system.
 	 * @throws UnsupportedOperationException if either Base is not an Identifier instance
@@ -41,6 +41,16 @@ public class IdentifierMatcher implements IMdmFieldMatcher {
 			}
 		}
 		CanonicalIdentifier right = IdentifierUtil.identifierDtFromIdentifier(theRightBase);
+		if (isEmpty(left.getValueElement()) || isEmpty(right.getValueElement())) {
+			return false;
+		}
 		return left.equals(right);
 	}
+
+	private boolean isEmpty(StringDt theValue) {
+		if (theValue == null) {
+			return true;
+		}
+		return theValue.isEmpty();
+	}
 }
diff --git a/hapi-fhir-server-mdm/src/test/java/ca/uhn/fhir/mdm/rules/matcher/IdentifierMatcherR4Test.java b/hapi-fhir-server-mdm/src/test/java/ca/uhn/fhir/mdm/rules/matcher/IdentifierMatcherR4Test.java
index 5e6758af0a0..66666446f8a 100644
--- a/hapi-fhir-server-mdm/src/test/java/ca/uhn/fhir/mdm/rules/matcher/IdentifierMatcherR4Test.java
+++ b/hapi-fhir-server-mdm/src/test/java/ca/uhn/fhir/mdm/rules/matcher/IdentifierMatcherR4Test.java
@@ -46,6 +46,17 @@ public class IdentifierMatcherR4Test extends BaseMatcherR4Test {
 		assertFalse(fieldMatch.match(ourFhirContext, rightNoValue, left).match);
 	}
 
+	@Test
+	public void testIdentifierMatchWithNoValues() {
+		Identifier left = new Identifier().setSystem(MATCHING_SYSTEM);
+		Identifier right = new Identifier().setSystem(MATCHING_SYSTEM);
+
+		MdmMatcherJson matcher = new MdmMatcherJson().setAlgorithm(MdmMatcherEnum.IDENTIFIER).setIdentifierSystem(MATCHING_SYSTEM);
+		MdmFieldMatchJson fieldMatch = new MdmFieldMatchJson().setMatcher(matcher);
+
+		assertFalse(fieldMatch.match(ourFhirContext, left, right).match);
+	}
+
 	@Test
 	public void testIdentifierNamedSystemMatch() {
 		Identifier left = new Identifier().setSystem(MATCHING_SYSTEM).setValue(MATCHING_VALUE);