Support running executables from dependencies.

sdk/lib/_internal/pub/lib/src/command/run.dart

Index: sdk/lib/_internal/pub/lib/src/command/run.dart
diff --git a/sdk/lib/_internal/pub/lib/src/command/run.dart b/sdk/lib/_internal/pub/lib/src/command/run.dart
index 73b62be8b425e433c0ab2575ae089b1623b2aa3a..5973ca78bc1ae743f63126694358719fba37edaf 100644
--- a/sdk/lib/_internal/pub/lib/src/command/run.dart
+++ b/sdk/lib/_internal/pub/lib/src/command/run.dart
@@ -39,6 +39,8 @@ class RunCommand extends PubCommand {
     }
 
     var environment;
+    var package = entrypoint.root.name;
+    var rootDir;
     var scriptPath;
     var args;
     return AssetEnvironment.create(entrypoint, BarbackMode.RELEASE,
@@ -55,40 +57,64 @@ class RunCommand extends PubCommand {
       var script = commandOptions.rest[0];
       args = commandOptions.rest.skip(1).toList();
 
+      // A command like "foo:bar" runs the "bar" script from the "foo" package.
+      // If there is no colon prefix, default to the root package.
+      if (script.contains(":")) {

[Sean Eagan, 2014/06/20 12:42:38]

Instead of inventing a syntax for this:

    pub run <package>:<path> [args...]

why not just use normal cli arguments:

    pub run [--package=<package>] <path> [args...]

?

[Bob Nystrom, 2014/06/20 17:35:27]

My hunch is that this will be a very common use case, so I wanted the syntax to
be lightweight. Something like:

$ pub run foo:bar arg arg

Having to do:

$ pub run --package foo bar arg arg

feels pretty painful to me.

+        var components = split1(script, ":");
+        package = components[0];
+        script = components[1];
+
+        var dep = entrypoint.root.immediateDependencies.firstWhere(
+            (dep) => dep.name == package, orElse: () => null);
+        if (dep == null) {
+          if (environment.graph.packages.containsKey(package)) {
+            dataError('Package "$package" is not an immediate dependency.\n'
+                'Cannot run executables in transitive dependencies.');
+          } else {
+            dataError('Could not find package "$package". Did you forget to '
+                'add a dependency?');
+          }
+        }
+      }
+
       // If the command has a path separator, then it's a path relative to the
       // root of the package. Otherwise, it's implicitly understood to be in
       // "bin".
-      var rootDir;
       var parts = path.split(script);
       if (parts.length > 1) {
-        scriptPath = "$script.dart";
+        if (package != entrypoint.root.name) {
+          usageError("Can not run an executable in a subdirectory of a "
+              "dependency.");
+        }
+
+        scriptPath = "${path.url.joinAll(parts.skip(1))}.dart";
         rootDir = parts.first;
       } else {
-        scriptPath = "bin/$script.dart";
+        scriptPath = "$script.dart";
         rootDir = "bin";
       }
 
-      // Serve the entire root-most directory containing the entrypoint. That
-      // ensures that, for example, things like `import '../../utils.dart';`
-      // will work from within some deeply nested script.
-      return environment.serveDirectory(rootDir);
+      if (package == entrypoint.root.name) {
+        // Serve the entire root-most directory containing the entrypoint. That
+        // ensures that, for example, things like `import '../../utils.dart';`
+        // will work from within some deeply nested script.
+        return environment.serveDirectory(rootDir);
+      } else {
+        // For other packages, always use the "bin" directory.
+        return environment.servePackageBinDirectory(package);
+      }
     }).then((server) {
       // Try to make sure the entrypoint script exists (or is generated) before
       // we spawn the process to run it.
       return environment.barback.getAssetById(
-          new AssetId(entrypoint.root.name, scriptPath)).then((_) {
-        return environment.getUrlsForAssetPath(scriptPath).then((urls) {
-          // Should only be bound to one port.
-          assert(urls.length == 1);
-
-          // Run in checked mode.
-          // TODO(rnystrom): Make this configurable.
-          args.insert(0, "--checked");
-
-          // The URL to the Dart entrypoint comes before the script arguments.
-          args.insert(1, urls[0].toString());
-          return Process.start(Platform.executable, args);
-        }).then((process) {
+          new AssetId(package, path.url.join(rootDir, scriptPath))).then((_) {
+
+        // Run in checked mode.
+        // TODO(rnystrom): Make this configurable.
+        var mode = "--checked";
+        args = [mode, server.url.resolve(scriptPath).toString()]..addAll(args);
+
+        return Process.start(Platform.executable, args).then((process) {
           // Note: we're not using process.std___.pipe(std___) here because
           // that prevents pub from also writing to the output streams.
           process.stderr.listen(stderr.add);
@@ -100,7 +126,12 @@ class RunCommand extends PubCommand {
       }).catchError((error, stackTrace) {
         if (error is! AssetNotFoundException) throw error;
 
-        log.error("Could not find $scriptPath.");
+        var message = "Could not find ${path.join(rootDir, scriptPath)}";
+        if (package != entrypoint.root.name) {
+          message += " in package $package";
+        }
+
+        log.error("$message.");
         log.fine(new Chain.forTrace(stackTrace));
         return flushThenExit(exit_codes.NO_INPUT);
       });