Add "pub run --list" command to show all available executables.

lib/src/command/run.dart

@@ -10,6 +10,8 @@ import 'package:path/path.dart' as p;
 import '../command.dart';
 import '../executable.dart';
 import '../io.dart';
+import '../log.dart' as log;
+import '../package.dart';
 import '../utils.dart';
 
 /// Handles the `run` pub command.
@@ -22,13 +24,20 @@ class RunCommand extends PubCommand {
   RunCommand() {
     argParser.addFlag("checked", abbr: "c",
         help: "Enable runtime type checks and assertions.");
+    argParser.addFlag('list', negatable: false,
+        help: 'List all available executables.');
     argParser.addOption("mode",
         help: 'Mode to run transformers in.\n'
               '(defaults to "release" for dependencies, "debug" for '
                 'entrypoint)');
   }
 
   Future run() async {
+    if (argResults['list']) {
+      _listExecutables();
+      return;
+    }
+
     if (argResults.rest.isEmpty) {
       usageException("Must specify an executable to run.");
     }
@@ -69,4 +78,58 @@ class RunCommand extends PubCommand {
         checked: argResults['checked'], mode: mode);
     await flushThenExit(exitCode);
   }
+
+  /// Lists all executables reachable from [entrypoint].
+  void _listExecutables() {
+    var packages = []
+      ..add(entrypoint.root)
+      ..addAll(entrypoint.root.immediateDependencies
+          .map((dep) => entrypoint.packageGraph.packages[dep.name]));
+
+    packages.forEach((Package package) {
+      var executables = _listExecutablesFor(package);
+      if (executables.isNotEmpty) {
+        log.message(_formatExecutables(package.name, executables.toList()));
+      }
+    });
+  }
+
+  /// Lists all Dart files in the `bin` directory of the [package].
+  ///
+  /// Returns file names without extensions.
+  List<String> _listExecutablesFor(Package package) {
+    return package
+        .listFiles(beneath: 'bin', recursive: false)
+        .where((executable) => p.extension(executable) == '.dart')
+        .map(p.basenameWithoutExtension);
+  }
+
+  /// Returns formatted string that lists [executables] for the [packageName].
+  /// Examples:
+  ///
+  ///     _formatExecutables('foo', ['foo'])        // -> 'foo'
+  ///     _formatExecutables('foo', ['bar'])        // -> 'foo:bar'
+  ///     _formatExecutables('foo', ['bar', 'foo']) // -> 'foo: foo, bar'
+  ///
+  /// Note the leading space before first executable and sorting order in the
+  /// last example.
+  String _formatExecutables(String packageName, List<String> executables) {
+    if (executables.length == 1) {
+      // If executable matches the package name omit the name of executable in
+      // the output.
+      return executables.first != packageName
+          ? '${log.bold(packageName)}:${executables.first}'
+          : log.bold(packageName);
+    } else {
+      // Sort executables to make executable that matches the package name to be
+      // the first in the list.
+      executables.sort((e1, e2) {
+        if (e1 == packageName) return -1;
+        else if (e2 == packageName) return 1;
+        else return e1.compareTo(e2);
+      });
+
+      return '${log.bold(packageName)}: ${executables.join(', ')}';
+    }
+  }
 }

test/run/errors_if_no_executable_is_given_test.dart

@@ -20,6 +20,7 @@ Must specify an executable to run.
 Usage: pub run <executable> [args...]
 -h, --help            Print this usage information.
 -c, --[no-]checked    Enable runtime type checks and assertions.
+    --list            List all available executables.
     --mode            Mode to run transformers in.
                       (defaults to "release" for dependencies, "debug" for entrypoint)
 

test/run/errors_if_path_in_dependency_test.dart

@@ -27,6 +27,7 @@ Cannot run an executable in a subdirectory of a dependency.
 Usage: pub run <executable> [args...]
 -h, --help            Print this usage information.
 -c, --[no-]checked    Enable runtime type checks and assertions.
+    --list            List all available executables.
     --mode            Mode to run transformers in.
                       (defaults to "release" for dependencies, "debug" for entrypoint)
 

test/run/list_test.dart

@@ -0,0 +1,134 @@
+// Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import '../descriptor.dart' as d;
+import '../test_pub.dart';
+
+main() {
+  integration("lists executables in entrypoint's bin", () {
+    d.dir(appPath, [
+      d.appPubspec(),
+      d.dir('bin', [
+        d.file('foo.dart'),
+        d.file('bar.dart')
+      ])
+    ]).create();
+
+    schedulePub(args: ['run', '--list'], output: 'myapp: bar, foo');
+  });
+
+  integration("doesn't list executables in bin's sub directories", () {
+    d.dir(appPath, [
+      d.appPubspec(),
+      d.dir('bin', [
+        d.file('foo.dart'),
+        d.dir('sub', [
+          d.file('bar.dart')
+        ])
+      ])
+    ]).create();
+
+    schedulePub(args: ['run', '--list'], output: 'myapp:foo');
+  });
+
+  integration('lists only Dart files', () {
+    d.dir(appPath, [
+      d.appPubspec(),
+      d.dir('bin', [
+        d.file('foo.dart'),
+        d.file('bar.sh')
+      ])
+    ]).create();
+
+    schedulePub(args: ['run', '--list'], output: 'myapp:foo');
+  });
+
+  integration('lists executables from a dependency', () {
+    d.dir('foo', [
+      d.libPubspec('foo', '1.0.0'),
+      d.dir('bin', [
+        d.file('bar.dart')
+      ])
+    ]).create();
+
+    d.dir(appPath, [
+      d.appPubspec({
+        'foo': {'path': '../foo'}
+      })
+    ]).create();
+
+    pubGet();
+    schedulePub(args: ['run', '--list'], output: 'foo:bar');
+  });
+
+  integration('lists executables only from immediate dependencies', () {
+    d.dir(appPath, [
+      d.appPubspec({
+        'foo': {'path': '../foo'}
+      })
+    ]).create();
+
+    d.dir('foo', [
+      d.libPubspec('foo', '1.0.0', deps: {
+        'baz': {'path': '../baz'}
+      }),
+      d.dir('bin', [
+        d.file('bar.dart')
+      ])
+    ]).create();
+
+    d.dir('baz', [
+      d.libPubspec('baz', '1.0.0'),
+      d.dir('bin', [
+        d.file('qux.dart')
+      ])
+    ]).create();
+
+
+    pubGet();
+    schedulePub(args: ['run', '--list'], output: 'foo:bar');
+  });
+
+  integration('applies formatting before printing executables', () {
+    d.dir(appPath, [
+      d.appPubspec({
+        'foo': {'path': '../foo'},
+        'bar': {'path': '../bar'}
+      }),
+      d.dir('bin', [
+        d.file('myapp.dart')
+      ])
+    ]).create();
+
+    d.dir('foo', [
+      d.libPubspec('foo', '1.0.0'),
+      d.dir('bin', [
+        d.file('baz.dart'),
+        d.file('foo.dart')
+      ])
+    ]).create();
+
+    d.dir('bar', [
+      d.libPubspec('bar', '1.0.0'),
+      d.dir('bin', [
+        d.file('qux.dart')
+      ])
+    ]).create();
+
+    pubGet();
+    schedulePub(args: ['run', '--list'], output: '''
+myapp
+bar:qux
+foo: foo, baz
+''');
+  });
+
+  integration('prints blank line when no executables found', () {
+    d.dir(appPath, [
+      d.appPubspec()
+    ]).create();
+
+    schedulePub(args: ['run', '--list'], output: '\n');
+  });
+}