MB-57888: Added unit tests covering all update paths

 - Few changes to the deleted fields logic to accommodate edge cases
 - Added deletion logic to vector paths
 - Tweaked deletion logic in index path

Author: Likith101

index/scorch/optimize_knn.go

@@ -85,8 +85,15 @@ func (o *OptimizeVR) Finish() error {
 					wg.Done()
 				}()
 				for field, vrs := range o.vrs {
-					vecIndex, err := segment.InterpretVectorIndex(field,
-						o.requiresFiltering, origSeg.deleted)
+					var vecIndex segment_api.VectorIndex
+					var err error
+					if info, ok := o.snapshot.updatedFields[field]; ok && info.All || info.Index {
+						vecIndex, err = segment.InterpretVectorIndex("",
+							o.requiresFiltering, origSeg.deleted)
+					} else {
+						vecIndex, err = segment.InterpretVectorIndex(field,
+							o.requiresFiltering, origSeg.deleted)
+					}
 					if err != nil {
 						errorsM.Lock()
 						errors = append(errors, err)

index/scorch/snapshot_index.go

@@ -623,7 +623,7 @@ func (is *IndexSnapshot) TermFieldReader(ctx context.Context, term []byte, field
 			// Skip fields that are supposed to have no indexing
 			if info, ok := is.updatedFields[field]; ok &&
 				(info.Index || info.All) {
-				dict = nil
+				dict, err = s.segment.Dictionary("")
 			} else {
 				dict, err = s.segment.Dictionary(field)
 			}

index_update.go

@@ -104,6 +104,17 @@ func DeletedFields(ori, upd *mapping.IndexMappingImpl) (map[string]*index.FieldI
 		if !info.All && !info.Index && !info.DocValues && !info.Store {
 			delete(fieldInfo, name)
 		}
+		if info.All {
+			if upd.IndexDynamic {
+				return nil, fmt.Errorf("Mapping cannot be removed when index dynamic is true")
+			}
+			if upd.StoreDynamic {
+				return nil, fmt.Errorf("Mapping cannot be removed when store dynamic is true")
+			}
+			if upd.DocValuesDynamic {
+				return nil, fmt.Errorf("Mapping cannot be removed when docvalues dynamic is true")
+			}
+		}
 	}
 	return fieldInfo, nil
 }
@@ -112,7 +123,7 @@ func compareMappings(ori, upd *mapping.IndexMappingImpl) (*defaultInfo, error) {
 	rv := &defaultInfo{}
 
 	if ori.TypeField != upd.TypeField &&
-		len(ori.TypeMapping) != 0 || len(upd.TypeMapping) != 0 {
+		(len(ori.TypeMapping) != 0 || len(upd.TypeMapping) != 0) {
 		return nil, fmt.Errorf("type field cannot be changed when type mappings are present")
 	}
 
@@ -264,7 +275,7 @@ func addFieldInfo(fInfo map[string]*index.FieldInfo, ori, upd *pathInfo, default
 			if err != nil {
 				return err
 			}
-			err = validateFieldInfo(info, updated, fInfo, ori)
+			err = validateFieldInfo(info, updated, fInfo, ori, oriFMapInfo)
 			if err != nil {
 				return err
 			}
@@ -285,7 +296,7 @@ func addFieldInfo(fInfo map[string]*index.FieldInfo, ori, upd *pathInfo, default
 			if err != nil {
 				return err
 			}
-			err = validateFieldInfo(info, updated, fInfo, ori)
+			err = validateFieldInfo(info, updated, fInfo, ori, oriFMapInfo)
 			if err != nil {
 				return err
 			}
@@ -395,7 +406,7 @@ func compareFieldMapping(original, updated *mapping.FieldMapping, defaultChanges
 		}
 	}
 
-	if rv.All || rv.Index || rv.Store {
+	if rv.All || rv.Index || rv.Store || rv.DocValues {
 		return rv, true, nil
 	}
 	return rv, false, nil
@@ -404,13 +415,21 @@ func compareFieldMapping(original, updated *mapping.FieldMapping, defaultChanges
 // After identifying changes, validate against the existing changes incase of duplicate fields.
 // In such a situation, any conflicting changes found will abort the update process
 func validateFieldInfo(newInfo *index.FieldInfo, updated bool, fInfo map[string]*index.FieldInfo,
-	ori *pathInfo) error {
+	ori *pathInfo, oriFMapInfo *fieldMapInfo) error {
 
 	var name string
-	if ori.fieldMapInfo[0].parent.parentPath == "" {
-		name = ori.fieldMapInfo[0].fieldMapping.Name
+	if oriFMapInfo.parent.parentPath == "" {
+		if oriFMapInfo.fieldMapping.Name == "" {
+			name = oriFMapInfo.parent.path
+		} else {
+			name = oriFMapInfo.fieldMapping.Name
+		}
 	} else {
-		name = ori.fieldMapInfo[0].parent.parentPath + "." + ori.fieldMapInfo[0].fieldMapping.Name
+		if oriFMapInfo.fieldMapping.Name == "" {
+			name = oriFMapInfo.parent.parentPath + "." + oriFMapInfo.parent.path
+		} else {
+			name = oriFMapInfo.parent.parentPath + "." + oriFMapInfo.fieldMapping.Name
+		}
 	}
 	if updated {
 		if ori.dynamic {