Hopefully a fix for #404, null ref while giving suggestions

lefthandedgoat · Mar 3, 2018 · 77fc454 · 77fc454
1 parent 283dd19
commit 77fc454
Showing 1 changed file with 7 additions and 4 deletions.
diff --git a/src/canopy/canopy.fs b/src/canopy/canopy.fs
@@ -1,6 +1,7 @@
 [<AutoOpen>]
 module canopy.core
 
+open System.Collections.ObjectModel
 open OpenQA.Selenium.Firefox
 open OpenQA.Selenium
 open OpenQA.Selenium.Interactions
@@ -189,10 +190,12 @@ let private suggestOtherSelectors cssSelector =
 	            }
             }
             return texts;"""
-        let classes = js classesViaJs :?> System.Collections.ObjectModel.ReadOnlyCollection<System.Object> |> Seq.map (fun item -> "." + item.ToString()) |> Array.ofSeq
-        let ids = js idsViaJs :?> System.Collections.ObjectModel.ReadOnlyCollection<System.Object> |> Seq.map (fun item -> "#" + item.ToString()) |> Array.ofSeq
-        let values = js valuesViaJs :?> System.Collections.ObjectModel.ReadOnlyCollection<System.Object> |> Seq.map (fun item -> item.ToString()) |> Array.ofSeq
-        let texts = js textsViaJs :?> System.Collections.ObjectModel.ReadOnlyCollection<System.Object> |> Seq.map (fun item -> item.ToString()) |> Array.ofSeq
+        let safeSeq orig = if orig = null then Seq.empty else orig
+        let safeToString orig = if orig = null then "" else orig.ToString()
+        let classes = js classesViaJs :?> ReadOnlyCollection<System.Object> |> safeSeq |> Seq.map (fun item -> "." + safeToString item) |> Array.ofSeq
+        let ids = js idsViaJs :?> ReadOnlyCollection<System.Object> |> safeSeq |> Seq.map (fun item -> "#" + safeToString item) |> Array.ofSeq
+        let values = js valuesViaJs :?> ReadOnlyCollection<System.Object> |> safeSeq |> Seq.map (fun item -> safeToString item) |> Array.ofSeq
+        let texts = js textsViaJs :?> ReadOnlyCollection<System.Object> |> safeSeq |> Seq.map (fun item -> safeToString item) |> Array.ofSeq
 
         let results =
             Array.append classes ids