use executablesIds instead of listFiles

* _isDartExecutable is simplified as extension check is performed by executablesIds

Author: akhomchenko

lib/src/command/deps.dart

@@ -16,16 +16,12 @@ import '../utils.dart';
 
 /// Returns `true` if [path] looks like a Dart entrypoint.
 bool _isDartExecutable(String path) {
-  if (p.extension(path) == '.dart') {
-    try {
-      var unit = analyzer.parseDartFile(path, parseFunctionBodies: false);
-      return isEntrypoint(unit);
-    } on analyzer.AnalyzerErrorGroup {
-      return false;
-    }
+  try {
+    var unit = analyzer.parseDartFile(path, parseFunctionBodies: false);
+    return isEntrypoint(unit);
+  } on analyzer.AnalyzerErrorGroup {
+    return false;
   }
-
-  return false;
 }
 
 /// Handles the `deps` pub command.
@@ -277,10 +273,9 @@ class DepsCommand extends PubCommand {
   /// Lists all Dart files in the `bin` directory of the [package].
   ///
   /// Returns file names without extensions.
-  List<String> _getExecutablesFor(Package package) => package
-      .listFiles(beneath: 'bin', recursive: false)
-      .where(_isDartExecutable)
-      .map(p.basenameWithoutExtension);
+  List<String> _getExecutablesFor(Package package) => package.executableIds
+      .where((e) => _isDartExecutable(p.absolute(package.dir, e.path)))
+      .map((e) => p.basenameWithoutExtension(e.path));
 
   /// Returns formatted string that lists [executables] for the [packageName].
   /// Examples: