Fix crash in case of empty # output

src/DocTests.jl

@@ -239,7 +239,9 @@ function eval_script(block, sandbox, meta::Dict, doc::Documents.Document, page)
     #
     #
     #       to mark `input`/`output` separation.
-    input, output = split(block.code, "# output\n", limit = 2)
+
+    # Append "\n" before split in case of empty output
+    input, output = split(block.code*"\n", "# output\n", limit = 2)
     input  = rstrip(input, '\n')
     output = lstrip(output, '\n')
     result = Result(block, input, output, meta[:CurrentFile])

test/doctests/src/working.md

@@ -52,4 +52,11 @@ Comments at the start:
 # .. should be ignored.
 julia> 2 + 2
 4
-```
+```
+
+Empty output:
+
+```jldoctest
+nothing
+# output
+```