fix unsafe case, keep original default value and add tests

Author: typotter

features/dd-sdk-android-flags/src/main/kotlin/com/datadog/android/flags/internal/DatadogFlagsClient.kt

@@ -141,10 +141,15 @@ internal class DatadogFlagsClient(
      * @return The map value of the flag, or the default value if unavailable.
      */
     override fun resolveStructureValue(flagKey: String, defaultValue: Map<String, Any?>): Map<String, Any?> {
-        // Convert Map to JSONObject for resolution, then convert back to Map
         val jsonDefault = defaultValue.toJSONObject()
         val jsonResult = resolveValue(flagKey, jsonDefault)
-        return jsonResult.toMap()
+
+        // Preserve original default value on failure (avoids round-trip conversion)
+        return if (jsonResult === jsonDefault) {
+            defaultValue
+        } else {
+            jsonResult.toMap()
+        }
     }
 
     /**

features/dd-sdk-android-flags/src/main/kotlin/com/datadog/android/flags/internal/JsonExtensions.kt

@@ -119,7 +119,7 @@ internal fun List<Any?>.toJSONArray(): JSONArray {
  * Converts a Kotlin value to a JSON-compatible value.
  *
  * Recursively handles nested structures:
- * - Map<*, *> → JSONObject
+ * - Map<*, *> → JSONObject (non-String keys converted via toString())
  * - List<*> → JSONArray
  * - null → JSONObject.NULL
  * - Primitives → unchanged
@@ -129,8 +129,16 @@ internal fun List<Any?>.toJSONArray(): JSONArray {
  */
 private fun convertToJsonValue(value: Any?): Any = when (value) {
     null -> JSONObject.NULL
-    is Map<*, *> -> (value as Map<String, Any?>).toJSONObject()
-    is List<*> -> (value as List<Any?>).toJSONArray()
+    is Map<*, *> -> {
+        // Convert keys to String (supports non-String keys via toString())
+        @Suppress("UNCHECKED_CAST")
+        val stringMap = value.entries.associate { (k, v) -> k.toString() to v }
+        stringMap.toJSONObject()
+    }
+    is List<*> -> {
+        @Suppress("UNCHECKED_CAST")
+        (value as List<Any?>).toJSONArray()
+    }
     else -> value // Primitives: String, Int, Long, Double, Boolean
 }
 

features/dd-sdk-android-flags/src/test/kotlin/com/datadog/android/flags/internal/DatadogFlagsClientTest.kt

@@ -646,7 +646,8 @@ internal class DatadogFlagsClientTest {
         }
         val fakeFlag = forge.getForgery<PrecomputedFlag>().copy(
             variationType = VariationType.OBJECT.value,
-            variationValue = fakeFlagValue.toString()
+            variationValue = fakeFlagValue.toString(),
+            doLog = true
         )
         val fakeContext = EvaluationContext(
             targetingKey = forge.anAlphabeticalString(),
@@ -664,6 +665,13 @@ internal class DatadogFlagsClientTest {
         assertThat(result["nested"]).isInstanceOf(Map::class.java)
         val nested = result["nested"] as Map<*, *>
         assertThat(nested["city"]).isEqualTo("NYC")
+
+        // Verify exposure tracked
+        verify(mockProcessor).processEvent(
+            flagName = eq(fakeFlagKey),
+            context = eq(fakeContext),
+            data = eq(fakeFlag)
+        )
     }
 
     @Test
@@ -681,6 +689,7 @@ internal class DatadogFlagsClientTest {
 
         // Then
         assertThat(result).isEqualTo(fakeDefaultValue)
+        verifyNoInteractions(mockProcessor)
     }
 
     @Test
@@ -699,6 +708,45 @@ internal class DatadogFlagsClientTest {
         verifyNoInteractions(mockRumEvaluationLogger)
     }
 
+    @Test
+    fun `M return empty map W resolveStructureValue() {empty map default, flag not found}`(forge: Forge) {
+        // Given
+        val fakeFlagKey = forge.anAlphabeticalString()
+        val fakeDefaultValue = emptyMap<String, Any?>()
+        whenever(mockFlagsRepository.getPrecomputedFlagWithContext(fakeFlagKey)) doReturn null
+
+        // When
+        val result = testedClient.resolveStructureValue(fakeFlagKey, fakeDefaultValue)
+
+        // Then
+        assertThat(result).isEmpty()
+        assertThat(result).isSameAs(fakeDefaultValue) // Preserves original reference
+        verifyNoInteractions(mockProcessor)
+    }
+
+    @Test
+    fun `M return default map W resolveStructureValue() {map default, type mismatch}`(forge: Forge) {
+        // Given
+        val fakeFlagKey = forge.anAlphabeticalString()
+        val fakeDefaultValue = mapOf("key" to "value")
+        val fakeFlag = forge.getForgery<PrecomputedFlag>().copy(
+            variationType = VariationType.STRING.value,
+            variationValue = "not-an-object"
+        )
+        val fakeContext = EvaluationContext(
+            targetingKey = forge.anAlphabeticalString(),
+            attributes = emptyMap()
+        )
+        whenever(mockFlagsRepository.getPrecomputedFlagWithContext(fakeFlagKey)) doReturn (fakeFlag to fakeContext)
+
+        // When
+        val result = testedClient.resolveStructureValue(fakeFlagKey, fakeDefaultValue)
+
+        // Then
+        assertThat(result).isEqualTo(fakeDefaultValue)
+        verifyNoInteractions(mockProcessor) // No exposure tracked for type mismatch
+    }
+
     // endregion
 
     // region Constructor Logic

features/dd-sdk-android-flags/src/test/kotlin/com/datadog/android/flags/internal/JsonExtensionsTest.kt

@@ -367,6 +367,19 @@ internal class JsonExtensionsTest {
         assertThat(obj.getInt("age")).isEqualTo(30)
     }
 
+    @Test
+    fun `M preserve nulls W toJSONArray then toList() {null in list}`() {
+        // Given
+        val list = listOf("a", null, "b", null)
+
+        // When
+        val jsonArray = list.toJSONArray()
+        val result = jsonArray.toList()
+
+        // Then
+        assertThat(result).containsExactly("a", null, "b", null)
+    }
+
     // endregion
 
     // region Round-trip conversion