fix: scan reads files passed on command-line

src/plcc/bin/scan

@@ -2,4 +2,4 @@
 source "$(dirname -- "${BASH_SOURCE[0]}" )/common.bash" && init
 
 assert_file_exists Java/Scan.class
-java Scan
+java Scan "$@"

tests/end-to-end/scan/reads-files-given-on-command-line.bats

@@ -0,0 +1,25 @@
+#!/usr/bin/env bats
+
+load '../relocate_to_temp.bash'
+
+@test "scan reads files passed on command-line" {
+  relocate_to_temp
+
+  cat << EOF > grammar
+skip WHITESPACE '\s'
+token FOO 'foo'
+token BAR 'bar'
+token ID '[A-Za-z]\w*'
+EOF
+
+  echo "foo bar \n foobar" > in.file
+
+  TOKENS="$(
+    plccmk -c grammar &&
+    scan in.file
+  )"
+
+  [[ "$TOKENS" =~ "FOO 'foo'" ]]
+  [[ "$TOKENS" =~ "BAR 'bar'" ]]
+  [[ "$TOKENS" =~ "ID 'foobar'" ]]
+}