From 972b9388e3ab23bf01f884cf8a4978396ffa70d4 Mon Sep 17 00:00:00 2001
From: e551763 <alexander.nikonoff@sbb.ch>
Date: Thu, 31 Oct 2024 12:42:50 +0100
Subject: [PATCH] fix: proper error message on attempt to set single value into
 multi-value field and vice-versa

Refs: SchweizerischeBundesbahnen/ch.sbb.polarion.extension.diff-tool#83
---
 .../extension/generic/service/PolarionService.java   | 12 ++++++++++--
 .../generic/service/PolarionServiceTest.java         |  8 +++++++-
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/app/src/main/java/ch/sbb/polarion/extension/generic/service/PolarionService.java b/app/src/main/java/ch/sbb/polarion/extension/generic/service/PolarionService.java
index 010733f..a0c20d4 100644
--- a/app/src/main/java/ch/sbb/polarion/extension/generic/service/PolarionService.java
+++ b/app/src/main/java/ch/sbb/polarion/extension/generic/service/PolarionService.java
@@ -215,15 +215,23 @@ public void setFieldValue(@NotNull IPObject ipObject, @NotNull String fieldId, O
                 FieldMetadata.fromPrototype(ipObject.getPrototype(), fieldId) : FieldMetadata.fromCustomField(ipObject.getCustomFieldPrototype(fieldId));
         Object valueToSet = value == null ? null : Optional.ofNullable(IConverter.getSuitableConverter(value, fieldMetadata.getType()))
                 .map(converter -> converter.convert(value, ConverterContext.builder().contextId(ipObject.getContextId()).enumsMapping(enumsMapping).build(), fieldMetadata)).orElse(value);
+        boolean multiValueField = fieldMetadata.getType() instanceof IListType;
         if (valueToSet == null) {
             if (fieldMetadata.isRequired()) {
                 throw new IllegalArgumentException("Cannot set empty value to the required field");
-            } else if (fieldMetadata.getType() instanceof IListType) {
+            } else if (multiValueField) {
                 valueToSet = new ArrayList<>(); //Multi-value fields expect empty list in case of empty value
             }
         }
+
         if (valueToSet instanceof List<?> valuesList) {
-            valueToSet = new CustomTypedList(ipObject, (IListType) fieldMetadata.getType(), fieldMetadata.isRequired(), valuesList);
+            if (multiValueField) {
+                valueToSet = new CustomTypedList(ipObject, (IListType) fieldMetadata.getType(), fieldMetadata.isRequired(), valuesList);
+            } else {
+                throw new IllegalArgumentException("Cannot set multi-value into field '%s'".formatted(fieldId));
+            }
+        } else if (multiValueField) {
+            throw new IllegalArgumentException("Cannot set single value to the multi-value field '%s'".formatted(fieldId));
         }
         if (fieldMetadata.isCustom()) {
             ipObject.setCustomField(fieldId, valueToSet);
diff --git a/app/src/test/java/ch/sbb/polarion/extension/generic/service/PolarionServiceTest.java b/app/src/test/java/ch/sbb/polarion/extension/generic/service/PolarionServiceTest.java
index b0ae9c8..f46c886 100644
--- a/app/src/test/java/ch/sbb/polarion/extension/generic/service/PolarionServiceTest.java
+++ b/app/src/test/java/ch/sbb/polarion/extension/generic/service/PolarionServiceTest.java
@@ -324,8 +324,9 @@ void testSetFieldValue() {
             List<String> listValue = List.of("value1", "value2");
 
             // primitive fields cannot receive lists
-            assertThrows(ClassCastException.class,
+            IllegalArgumentException multiValueException = assertThrows(IllegalArgumentException.class,
                     () -> polarionService.setFieldValue(workItem, "genericFieldId", listValue, enumsMapping));
+            assertEquals("Cannot set multi-value into field 'genericFieldId'", multiValueException.getMessage());
 
             // lists must be supported
             genericFieldMetadata.setType(new ListType("listTypeId", FieldType.STRING.getType()));
@@ -333,6 +334,11 @@ void testSetFieldValue() {
             verify(workItem, times(3)).setValue(anyString(), any());
             verify(workItem, times(1)).setCustomField(anyString(), any());
 
+            // multi fields cannot receive single values
+            IllegalArgumentException singleValueException = assertThrows(IllegalArgumentException.class,
+                    () -> polarionService.setFieldValue(workItem, "genericFieldId", 42, enumsMapping));
+            assertEquals("Cannot set single value to the multi-value field 'genericFieldId'", singleValueException.getMessage());
+
             // nulls for list-typed fields must be converted to an empty list
             polarionService.setFieldValue(workItem, "genericFieldId", null, enumsMapping);
             verify(workItem, times(1)).setValue("genericFieldId", new ArrayList<>());