Check diagnostics for recursive and simultaneous bindings

test_errors.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+set -eu
+test_dir=$(mktemp -d)
+trap 'rm -rf "$test_dir"' EXIT HUP INT TERM
+for source in \
+  'let _ = let%continue rec x = f in x' \
+  'let _ = let%continue x = f and y = g in x' \
+  'let _ = [%continue 42]'
+do
+  printf '%s\n' "$source" > "$test_dir/invalid.ml"
+  if "${OCAMLC:-ocamlc}" -ppx ./continuum_ppx -c "$test_dir/invalid.ml" 2> "$test_dir/error"; then
+    echo "Unexpected success: $source" >&2
+    exit 1
+  fi
+  grep -q 'continuum_ppx: expected' "$test_dir/error"
+done
+echo 'continuum_ppx: invalid syntax checks passed'