Fix aggregate function errors (#1375)

* Test cases

* Fix AllTrue and AnyTrue

* Fix standard deviation aggregators

* Tests

---------

Co-authored-by: JP <jonathan.i.percival@gmail.com>

Src/java/engine/src/main/java/org/opencds/cqf/cql/engine/elm/executing/AllTrueEvaluator.java

@@ -15,7 +15,7 @@ public class AllTrueEvaluator {
 
  public static Boolean allTrue(Object src) {
  if (src == null) {
- return null;
+ return true;
  }
 
  if (src instanceof Iterable) {

Src/java/engine/src/main/java/org/opencds/cqf/cql/engine/elm/executing/AnyTrueEvaluator.java

@@ -14,9 +14,8 @@
 public class AnyTrueEvaluator {
 
  public static Boolean anyTrue(Object src) {
-
  if (src == null) {
- return null;
+ return false;
  }
 
  if (src instanceof Iterable) {

Src/java/engine/src/main/java/org/opencds/cqf/cql/engine/elm/executing/PopulationStdDevEvaluator.java

@@ -31,6 +31,10 @@ public static Object popStdDev(Object source, State state) {
  }
 
  Object variance = PopulationVarianceEvaluator.popVariance(source, state);
+ // The cases in which PopulationVariance returns null are the same as those where PopulationStdDev does.
+ if(variance == null) {
+ return null;
+ }
 
  return variance instanceof BigDecimal
  ? PowerEvaluator.power(variance, new BigDecimal("0.5"))

Src/java/engine/src/main/java/org/opencds/cqf/cql/engine/elm/executing/StdDevEvaluator.java

@@ -31,6 +31,10 @@ public static Object stdDev(Object source, State state) {
  }
 
  Object variance = VarianceEvaluator.variance(source, state);
+ // The cases in which Variance returns null are the same as those where StdDev does.
+ if(variance == null) {
+ return null;
+ }
 
  return variance instanceof BigDecimal
  ? PowerEvaluator.power(variance, new BigDecimal("0.5"))

Src/java/engine/src/test/java/org/opencds/cqf/cql/engine/execution/CqlAggregateFunctionsTest.java

@@ -2,10 +2,13 @@
 
 import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.nullValue;
 import static org.junit.jupiter.api.Assertions.*;
 
 import java.math.BigDecimal;
 import java.util.Arrays;
+
+import org.hamcrest.core.IsNull;
 import org.junit.jupiter.api.Test;
 import org.opencds.cqf.cql.engine.elm.executing.AnyTrueEvaluator;
 import org.opencds.cqf.cql.engine.elm.executing.AvgEvaluator;
@@ -43,6 +46,9 @@ void all_aggregate_function_tests() {
  value = results.forExpression("AllTrueEmptyList").value();
  assertThat(value, is(true));
 
+ value = results.forExpression("AllTrueIsTrueWhenNull").value();
+ assertThat(value, is(true));
+
  value = results.forExpression("AnyTrueAllTrue").value();
  assertThat(value, is(true));
 
@@ -70,6 +76,10 @@ void all_aggregate_function_tests() {
  value = results.forExpression("AnyTrueEmptyList").value();
  assertThat(value, is(false));
 
+ value = results.forExpression("AnyTrueIsFalseWhenNull").value();
+ assertThat(value, is(false));
+
+
  try {
  value = AnyTrueEvaluator.anyTrue(Arrays.asList("this", "is", "error"));
  fail();
@@ -152,15 +162,24 @@ void all_aggregate_function_tests() {
  ((BigDecimal) value)
  .compareTo(new BigDecimal("1.41421356"))); // 23730951454746218587388284504413604736328125
 
+ value = results.forExpression("PopulationStdDevIsNull").value();
+ assertThat(value, is(nullValue()));
+
  value = results.forExpression("PopVarianceTest1").value();
  assertEquals(0, ((BigDecimal) value).compareTo(new BigDecimal("2.0")));
 
+ value = results.forExpression("PopVarianceIsNull").value();
+ assertThat(value, is(nullValue()));
+
  value = results.forExpression("StdDevTest1").value();
  assertEquals(
  0,
  ((BigDecimal) value)
  .compareTo(new BigDecimal("1.58113883"))); // 00841897613935316257993690669536590576171875
 
+ value = results.forExpression("StdDevIsNull").value();
+ assertThat(value, is(nullValue()));
+
  value = results.forExpression("SumTest1").value();
  assertThat(value, is(new BigDecimal("20.0")));
 

Src/java/engine/src/test/resources/org/opencds/cqf/cql/engine/execution/CqlAggregateFunctionsTest.cql

@@ -8,7 +8,7 @@ define AllTrueAllTrueFalseTrue : AllTrue({true,false,true})
 define AllTrueAllFalseTrueFalse : AllTrue({false,true,false})
 define AllTrueNullFirst : AllTrue({null,true,true})
 define AllTrueEmptyList : AllTrue({})
-
+define AllTrueIsTrueWhenNull : AllTrue(null)
 //AnyTrue
 define AnyTrueAllTrue : AnyTrue({true,true})
 define AnyTrueAllFalse : AnyTrue({false,false})
@@ -19,6 +19,7 @@ define AnyTrueFalseFirst : AnyTrue({false,true})
 define AnyTrueNullFirstThenTrue : AnyTrue({null,true})
 define AnyTrueNullFirstThenFalse : AnyTrue({null,false})
 define AnyTrueEmptyList : AnyTrue({})
+define AnyTrueIsFalseWhenNull : AnyTrue(null)
 
 //Avg
 define AvgTest1: Avg({ 1.0, 2.0, 3.0, 6.0 })
@@ -57,12 +58,15 @@ define ModeTestTime: Mode({ @T15:59:59.999, @T05:59:59.999, @T20:59:59.999, @T05
 
 //PopulationStdDev
 define PopStdDevTest1: PopulationStdDev({ 1.0, 2.0, 3.0, 4.0, 5.0 })
+define PopulationStdDevIsNull: PopulationStdDev({ null as Quantity, null as Quantity, null as Quantity })
 
 //PopulationVariance
 define PopVarianceTest1: PopulationVariance({ 1.0, 2.0, 3.0, 4.0, 5.0 })
+define PopVarianceIsNull: PopulationVariance({ null as Quantity, null as Quantity, null as Quantity })
 
 //StdDev
 define StdDevTest1: StdDev({ 1.0, 2.0, 3.0, 4.0, 5.0 })
+define StdDevIsNull: StdDev({ null as Quantity, null as Quantity, null as Quantity })
 
 //Sum
 define SumTest1: Sum({ 6.0, 2.0, 3.0, 4.0, 5.0 })