Work around exception when jshint accesses console

When checking multiple files, JSHint 1.1.0 runs into a condition where
it tries to access the console object, leading to a runtime exception.

The workaround is to fake a console object with no-ops.

See jshint/jshint#931

Author: ralfstx

bundles/com.eclipsesource.jshint/src/com/eclipsesource/jshint/JSHint.java

@@ -47,9 +47,9 @@ public class JSHint {
 
   private static final String DEFAULT_JSHINT_VERSION = "1.1.0";
   private static final int DEFAULT_JSHINT_INDENT = 4;
+  private Function fakeConsole;
   private Function jshint;
   private Object opts;
-  private ScriptableObject scope;
   private int indent = DEFAULT_JSHINT_INDENT;
 
   /**
@@ -171,8 +171,11 @@ public static String getDefaultLibraryVersion() {
   private void load( Reader reader ) throws IOException {
     Context context = Context.enter();
     try {
-      scope = context.initStandardObjects();
+      ScriptableObject scope = context.initStandardObjects();
       context.evaluateReader( scope, reader, "jshint library", 1, null );
+      String code = "fakeConsole = function(){ console = {log:function(){},error:function(){},trace:function(){}}; };";
+      context.evaluateString( scope, code, "fake console", 2, null );
+      fakeConsole = (Function)scope.get( "fakeConsole" );
       jshint = findJSHintFunction( scope );
     } catch( RhinoException exception ) {
       throw new IllegalArgumentException( "Could not evaluate JavaScript input", exception );
@@ -184,6 +187,8 @@ private void load( Reader reader ) throws IOException {
   private boolean checkCode( Context context, String code ) {
     try {
       Object[] args = new Object[] { code, opts };
+      ScriptableObject scope = context.initStandardObjects();
+      fakeConsole.call( context, scope, null, null );
       return ( (Boolean)jshint.call( context, scope, null, args ) ).booleanValue();
     } catch( JavaScriptException exception ) {
       String message = "JavaScript exception thrown by JSHint: " + exception.getMessage();

tests/com.eclipsesource.jshint.test/src/com/eclipsesource/jshint/JSHint_Test.java

@@ -35,7 +35,7 @@ public class JSHint_Test {
   @Before
   public void setUp() throws IOException {
     problems = new ArrayList<Problem>();
-    handler = new TestHandler();
+    handler = new TestHandler( problems );
     jsHint = new JSHint();
     jsHint.load();
   }
@@ -284,11 +284,63 @@ public void errorAtEndDoesNotThrowException() {
     jsHint.check( "var x = 1;\t#", handler );
   }
 
-  private class TestHandler implements ProblemHandler {
+  @Test
+  public void checkSameInputTwice() {
+    jsHint.configure( new Configuration().addOption( "undef", true ) );
+    LoggingHandler handler1 = new LoggingHandler();
+    LoggingHandler handler2 = new LoggingHandler();
+
+    jsHint.check( "var x = 1;\t#", handler1 );
+    jsHint.check( "var x = 1;\t#", handler2 );
+
+    assertTrue( handler1.toString().length() > 0 );
+    assertEquals( handler1.toString(), handler2.toString() );
+  }
+
+  @Test
+  public void checkMultipleFiles() {
+    // see https://github.com/jshint/jshint/issues/931
+    jsHint.configure( new Configuration().addOption( "undef", true ) );
+
+    jsHint.check( "var x = 1;\t#", handler );
+    jsHint.check( "var x = 1;\t#", handler );
+    jsHint.check( "var x = 1;\t#", handler );
+    jsHint.check( "var x = 1;\t#", handler );
+    jsHint.check( "var x = 1;\t#", handler );
+  }
+
+  private static class LoggingHandler implements ProblemHandler {
+
+    StringBuilder log = new StringBuilder();
+
+    public void handleProblem( Problem problem ) {
+      log.append( problem.getLine() );
+      log.append( ':' );
+      log.append( problem.getCharacter() );
+      log.append( ':' );
+      log.append( problem.getMessage() );
+      log.append( '\n' );
+    }
+
+    @Override
+    public String toString() {
+      return log.toString();
+    }
+
+  }
+
+  private static class TestHandler implements ProblemHandler {
+
+    private final List<Problem> problems;
+
+    public TestHandler( List<Problem> problems ) {
+      this.problems = problems;
+    }
 
     public void handleProblem( Problem problem ) {
       problems.add( problem );
     }
+
   }
 
 }