Fix DartRunner to work properly with --check-only cmdline flag

compiler/java/com/google/dart/runner/DartRunner.java

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2012, 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.
 
 package com.google.dart.runner;
 
 import com.google.common.base.Joiner;
 import com.google.common.collect.Lists;
 import com.google.common.io.CharStreams;
 import com.google.common.io.Files;
 import com.google.dart.compiler.Backend;
@@ skipping 139 matching lines @@
               + dir + ":  Permission denied.");
         }
       }
       try {
         Files.write(compiled.js, outFile, Charset.defaultCharset());
       } catch (IOException e) {
         throw new RunnerError(e);
       }
     }
 
-    if (!options.shouldCompileOnly()) {
+    if (!options.shouldCompileOnly() && !options.checkOnly()) {
       runApp(compiled, app.getName(), options, scriptArguments.toArray(new String[0]),
              stdout, stderr);
     }
   }
 
   private static void printUsageAndThrow(CmdLineParser cmdLineParser, String reason)
       throws RunnerError {
 
     StringBuilder usage = new StringBuilder();
     usage.append(reason);
@@ skipping 63 matching lines @@
 
   public static void compileAndRunApp(LibrarySource app,
                                       DartRunnerOptions options,
                                       CompilerConfiguration config,
                                       DartCompilerListener listener,
                                       String[] dartArguments,
                                       PrintStream stdout,
                                       PrintStream stderr)
       throws RunnerError {
     CompilationResult compiled = compileApp(
-        app, Collections.<LibrarySource>emptyList(), config, listener);
+        app, Collections.<LibrarySource>emptyList(), config, listener, options);
     runApp(compiled, app.getName(), options, dartArguments, stdout, stderr);
   }
 
   private static void runApp(CompilationResult compiled,
                              String sourceName,
                              DartRunnerOptions options,
                              String[] scriptArguments,
                              PrintStream stdout,
                              PrintStream stderr)
       throws RunnerError {
@@ skipping 30 matching lines @@
       @Override
       public boolean expectEntryPoint() {
         return true;
       }
 
       @Override
       public boolean typeErrorsAreFatal() {
         return options.typeErrorsAreFatal();
       }
     };
-    return compileApp(app, imports, config, listener);
+    return compileApp(app, imports, config, listener, options);
   }
 
   /**
    * Parses and compiles an application to Javascript.
    */
   private static CompilationResult compileApp(LibrarySource app,
                                               List<LibrarySource> imports,
                                               CompilerConfiguration config,
-                                              DartCompilerListener listener) throws RunnerError {
+                                              DartCompilerListener listener,
+                                              final DartRunnerOptions options) throws RunnerError {

[scheglov, 2012/02/06 13:09:54]

Would be good to use same order or arguments as in "compileAndRunApp": app,
options, config, listener.

[zundel, 2012/02/06 16:01:56]

Done.

     try {
       final RunnerDartArtifactProvider provider = new RunnerDartArtifactProvider();
       String errmsg = DartCompiler.compileLib(app, imports, config, provider, listener);
       if (errmsg != null) {
          throw new RunnerError(errmsg);
       }
       Backend backend = config.getBackends().get(0);
 
       SourceMapping mapping = null;
       if (config.getCompilerOptions().generateSourceMaps()) {
@@ skipping 14 matching lines @@
 
             });
           } catch (SourceMapParseException e) {
             throw new AssertionError(e);
           } finally {
             mr.close();
           }
         }
       }
 
-      Reader r = provider.getArtifactReader(app, "", backend.getAppExtension());
-      String js = CharStreams.toString(r);
-      r.close();
-      return new CompilationResult(js, mapping);
+      if (!options.checkOnly()) {
+        Reader r = provider.getArtifactReader(app, "", backend.getAppExtension());
+        String js = CharStreams.toString(r);
+        r.close();
+        return new CompilationResult(js, mapping);
+      }
+      return null;
     } catch (IOException e) {
       // This can't happen; it's just a StringWriter.
       throw new AssertionError(e);
     }
   }
 }