JSInterp: fix switch instruction with condition inside it's branches (#149)

Author: LeoVgr

TestHScript.hx

@@ -125,15 +125,19 @@ class TestHScript extends TestCase {
 		assertScript("var f:(x:Int)->(Int, Int)->Int = (x:Int) -> (y:Int, z:Int) -> x + y + z; f(3)(1, 2)", 6, null, true);
 		assertScript("var a = 10; var b = 5; a - -b", 15);
 		assertScript("var a = 10; var b = 5; a - b / 2", 7.5);
-		assertScript("var a; a", null);
-		assertScript("var a = 1, b = 5; a + b;", 6);
-		assertScript("var a, b = 5; if (a == null) a = 2; a + b;", 7);
-		assertScript("var a:Int; a", null, null, true);
-		assertScript("var a:Int = 1, b:Int = 5; a + b;", 6, null, true);
-		assertScript("var a:Int, b:Int = 5; if (a == null) a = 2; a + b;", 7, null, true);
+		assertScript("var a; a", null);
+		assertScript("var a = 1, b = 5; a + b;", 6);
+		assertScript("var a, b = 5; if (a == null) a = 2; a + b;", 7);
+		assertScript("var a:Int; a", null, null, true);
+		assertScript("var a:Int = 1, b:Int = 5; a + b;", 6, null, true);
+		assertScript("var a:Int, b:Int = 5; if (a == null) a = 2; a + b;", 7, null, true);
 		assertScript("false && xxx", false);
 		assertScript("true || xxx", true);
 		assertScript("[for( x in arr ) switch( x ) { case 1: 55; case 3: 66; default: 0; }].join(':')",'55:0:66',{ arr : [1,2,3] });
+		assertScript("switch( x ) { case 1: 55; case 3: 66; default: 0; }",66 ,{ x : 3 });
+		assertScript("var a = 1; switch( b ) { default: a = 2; }; a", 2, { b : 2 });
+		assertScript("var a = 1; switch( b ) { case 2: a = 100; default: a = 2; }; a", 100, { b : 2 });
+		assertScript("var a = 3; switch( b ) { case 2: if (a == 1) { a = 100; } else { a = 99; }; default: a = 2; }; a", 99, { b : 2 });
 	}
 
 	function testNullFieldAccess():Void {
@@ -256,4 +260,4 @@ class TestHScript extends TestCase {
 		#end
 	}
 
-}
+}

hscript/JsInterp.hx

@@ -275,7 +275,7 @@ class JsInterp extends Interp {
 		case EIf(cond,e1,e2):
 			return 'if( ${exprCond(cond)} ) ${exprJS(e1)}'+(e2 == null ? "" : 'else ${exprJS(e2)}');
 		case ETernary(cond, e1, e2):
-			return '(${exprCond(cond)} ? ${exprValue(e1)} : ${exprValue(e2)})';
+			return '(${exprCond(cond)} ? ${exprValue(e1)} : ${e2 == null ? 'undefined' : exprValue(e2)})';
 		case EWhile(cond, e):
 			return 'while( ${exprValue(cond)} ) ${exprJS(e)}';
 		case EFor(v, it, e):