FHIRPath constant value null casting bug fix (#2012)

* Add null check for the retrieved value from a constant * Add new test and rename tests * Use safe casting * Use = instead of lambda --------- Co-authored-by: Francis Odhiambo Otieno <[email protected]>
google · Jun 7, 2023 · e322dd4 · e322dd4
1 parent f787d5b
commit e322dd4
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Showing 2 changed files with 11 additions and 6 deletions.
diff --git a/.../src/main/java/com/google/android/fhir/datacapture/fhirpath/FHIRPathEngineHostServices.kt b/.../src/main/java/com/google/android/fhir/datacapture/fhirpath/FHIRPathEngineHostServices.kt
@@ -25,10 +25,8 @@ import org.hl7.fhir.r4.utils.FHIRPathEngine
  * Resolves constants defined in the fhir path expressions beyond those defined in the specification
  */
 internal object FHIRPathEngineHostServices : FHIRPathEngine.IEvaluationContext {
-  override fun resolveConstant(appContext: Any?, name: String?, beforeContext: Boolean): Base? {
-    return if (appContext is Map<*, *> && appContext.containsKey(name)) appContext[name] as Base
-    else null
-  }
+  override fun resolveConstant(appContext: Any?, name: String?, beforeContext: Boolean): Base? =
+    (appContext as? Map<*, *>)?.get(name) as? Base
 
   override fun resolveConstantType(appContext: Any?, name: String?): TypeDetails {
     throw UnsupportedOperationException()

diff --git a/.../test/java/com/google/android/fhir/datacapture/fhirpath/FHIRPathEngineHostServicesTest.kt b/.../test/java/com/google/android/fhir/datacapture/fhirpath/FHIRPathEngineHostServicesTest.kt
@@ -27,19 +27,26 @@ import org.junit.Test
 class FHIRPathEngineHostServicesTest {
 
   @Test
-  fun testFHIRPathHostServices_resolveConstantValueNotPresent_returnsNull() {
+  fun testFHIRPathHostServices_resolveConstantKeyNotPresent_returnsNull() {
     val answer = FHIRPathEngineHostServices.resolveConstant(mapOf("A" to IntegerType(1)), "B", true)
 
     assertThat(answer).isNull()
   }
 
   @Test
-  fun testFHIRPathHostServices_resolveConstantValuePresent_returnsNotNull() {
+  fun testFHIRPathHostServices_resolveConstantKeyAndValuePresent_returnsNotNull() {
     val answer = FHIRPathEngineHostServices.resolveConstant(mapOf("A" to IntegerType(1)), "A", true)
 
     assertThat((answer as Type).asStringValue()).isEqualTo("1")
   }
 
+  @Test
+  fun testFHIRPathHostServices_resolveConstantKeyPresentAndValueNotPresent_returnsNull() {
+    val answer = FHIRPathEngineHostServices.resolveConstant(mapOf("A" to null), "A", true)
+
+    assertThat(answer).isNull()
+  }
+
   @Test
   fun testFHIRPathHostServices_resolveConstantNullAppContext_returnsNull() {
     val answer = FHIRPathEngineHostServices.resolveConstant(null, "A", true)