try to use lwgeom to make valid; #88 (comment)

DESCRIPTION

@@ -26,7 +26,8 @@ Imports:
     sf (>= 0.5-2),
     shiny
 Suggests:
-    crayon
+    crayon,
+    lwgeom
 Enhances:
     geojsonio
 Encoding: UTF-8

R/edit.R

@@ -300,6 +300,21 @@ editFeatures.sf = function(
 
   merged <- dplyr::select_(merged, "-edit_id")
 
+  # check to see if the result is valid with lwgeom if available and make valid
+  #   if error then return the invalid merged with a warning
+  if(requireNamespace("lwgeom")) {
+    tryCatch(
+      {
+        merged <- st_make_valid(merged)
+      },
+      error = function(e) {
+        warn("unable to make valid with lwgeom; please inspect closely", call. = FALSE)
+      }
+    )
+  } else {
+    message("lwgeom package not available so could not test validity")
+  }
+
   # return merged features
   if(record==TRUE) {
     attr(merged, "recorder") <- attr(crud, "recorder", exact=TRUE)