diff --git a/bin/dcat.dart b/bin/dcat.dart
index c026f8e..fed17f8 100644
--- a/bin/dcat.dart
+++ b/bin/dcat.dart
@@ -113,13 +113,13 @@ Future<ArgParser> setupArgsParser() async {
       negatable: false,
       abbr: 's',
       help: 'suppress repeated empty output lines');
-  parser.addFlag(versionFlag,
-      negatable: false, help: 'output version information and exit');
   parser.addFlag('ignored', negatable: false, hide: true, abbr: 'u');
   parser.addFlag(showNonPrintingFlag,
       negatable: false,
       abbr: 'v',
       help: 'use ^ and M- notation, except for LFD and TAB');
+  parser.addFlag(versionFlag,
+      negatable: false, help: 'output version information and exit');
 
   return parser;
 }
diff --git a/lib/dcat.dart b/lib/dcat.dart
index 5bf9b96..40867de 100644
--- a/lib/dcat.dart
+++ b/lib/dcat.dart
@@ -36,8 +36,6 @@ class CatResult {
   /// The list of errors.
   final List<CatError> errors = [];
 
-  CatResult();
-
   /// Returns `true` if the [exitCode] is [exitFailure].
   bool get isFailure => exitCode == exitFailure;
 
@@ -47,11 +45,7 @@ class CatResult {
   /// Adds an error [message] and [path].
   void addError(String message, {String? path}) {
     exitCode = exitFailure;
-    if (path != null && path.isNotEmpty) {
-      errors.add(CatError(message, path: path));
-    } else {
-      errors.add(CatError(message));
-    }
+    errors.add(CatError(message, path: path));
   }
 }
 
@@ -147,11 +141,10 @@ Future<void> _copyStream(
               squeeze = 0;
             }
           }
-          if (showLineNumbers || numberNonBlank) {
-            if (!numberNonBlank || ch != _lineFeed) {
-              buff.addAll('${++lastLine.lineNumber}'.padLeft(6).codeUnits);
-              buff.add(tab);
-            }
+          if ((showLineNumbers || numberNonBlank) &&
+              (!numberNonBlank || ch != _lineFeed)) {
+            buff.addAll('${++lastLine.lineNumber}'.padLeft(6).codeUnits);
+            buff.add(tab);
           }
         }
         lastLine.lastChar = ch;
diff --git a/test.sh b/test.sh
index 9f6beaa..34747b3 100755
--- a/test.sh
+++ b/test.sh
@@ -5,18 +5,27 @@ TMPDCAT=/tmp/tmp-dcat
 RED='\033[0;31m'
 GREEN='\033[0;32m'
 
-for o in -A -b -e -E -n -s -t -T -v
+checkDiff () {
+    if  ! $(cmp -s $TMPCAT $TMPDCAT);
+    then
+        echo -e "${RED}Test failed: $1" >&2
+        exit
+    fi  
+}
+
+for o in '' -A -b -e -E -n -s -t -T -v '-Abs'
 do
     echo -e "Testing: cat $o"
     cat $o test/* > $TMPCAT
     bin/dcat $o test/* > $TMPDCAT
-    if  ! $(diff -q $TMPCAT $TMPDCAT);
-    then
-        echo -e "${RED}Test failed: $o" >&2
-        exit
-    fi
+    checkDiff "cat $o"
 done
 
+echo -e "Testing: cat -"
+echo "This is a test" | cat - test/* > $TMPCAT
+echo "This is a test" | bin/dcat - test/* > $TMPDCAT
+checkDiff "cat -"
+
 rm -rf $TMPCAT $TMPDCAT
 
 echo -e "${GREEN}All tests passed."
diff --git a/test/dcat_test.dart b/test/dcat_test.dart
index e7707b6..a9f477b 100644
--- a/test/dcat_test.dart
+++ b/test/dcat_test.dart
@@ -16,16 +16,16 @@ void main() {
   const sourceFile = 'bin/dcat.dart';
 
   int exitCode;
-  final tempDir = Directory.systemTemp.createTempSync();
+  final tmpDir = Directory.systemTemp.createTempSync();
 
   Stream<List<int>> mockStdin({String text = sampleText}) async* {
     yield text.codeUnits;
   }
 
   File makeTmpFile() =>
-      File("${tempDir.path}/tmp-${DateTime.now().millisecondsSinceEpoch}.txt");
+      File("${tmpDir.path}/${DateTime.now().millisecondsSinceEpoch}.txt");
 
-  tearDownAll(() => tempDir.delete(recursive: true));
+  tearDownAll(() => tmpDir.delete(recursive: true));
 
   group('app', () {
     test('--help', () async {