Fix for Saltarelle#423, allow state machine to rethrow errors

nippur72 · Jun 3, 2015 · 6d1d662 · 6d1d662
1 parent ea32c51
commit 6d1d662
Showing 1 changed file with 13 additions and 1 deletion.
diff --git a/Compiler/JSModel/StateMachineRewrite/StateMachineRewriter.cs b/Compiler/JSModel/StateMachineRewrite/StateMachineRewriter.cs
@@ -155,7 +155,9 @@ private JsBlockStatement ProcessAsyncMethod(JsBlockStatement statement, string s
 			if (taskCompletionSource != null)
 				body = JsStatement.Try(body, JsStatement.Catch(catchVariable, JsStatement.Block(makeSetException(JsExpression.Identifier(catchVariable)))), null);
 
-			IEnumerable<JsVariableDeclaration> declarations = new[] { JsStatement.Declaration(_stateVariableName, JsExpression.Number(0)) };
+			IEnumerable<JsVariableDeclaration> declarations = new[] { JsStatement.Declaration(_stateVariableName, JsExpression.Number(0)), 
+																						 JsStatement.Declaration("$$ex", null) 
+																					  };
 			if (taskCompletionSource != null)
 				declarations = declarations.Concat(new[] { taskCompletionSource });
 			declarations = declarations.Concat(hoistResult.Item2.Select(v => JsStatement.Declaration(v, null)));
@@ -499,6 +501,16 @@ private bool HandleTryStatement(JsTryStatement stmt, StackEntry location, Immuta
 					currentBlock.Add(newBlock);
 				}
 
+				// adds: if ($$ex !== undefined) throw $$ex;
+				var reThrow = JsStatement.If( JsExpression.NotSame(JsExpression.Identifier("$$ex"),JsExpression.Identifier("undefined")),
+															JsStatement.Throw(JsExpression.Identifier("$$ex")),null);
+
+				// rewrite 'guarded' putting 'reThrow' as first statement of the block
+				var newGuarded = new List<JsStatement>();
+				newGuarded.Add(reThrow);
+				newGuarded.AddRange(guarded.Statements);															
+				guarded = JsStatement.Block(newGuarded);
+
 				currentBlock.Add(JsStatement.Try(guarded, @catch, @finally));
 				return true;
 			}