js: fix string.bytes codegen, readline, add tests for strings (#12060)

vlib/v/gen/js/builtin_types.v

@@ -111,10 +111,18 @@ fn (mut g JsGen) sym_to_js_typ(sym ast.TypeSymbol) string {
 	return styp
 }
 
+/*
 pub fn (mut g JsGen) base_type(t ast.Type) string {
 	mut styp := g.cc_type(t, true)
 	return styp
 }
+*/
+fn (mut g JsGen) base_type(_t ast.Type) string {
+	t := g.unwrap_generic(_t)
+	share := t.share()
+	mut styp := if share == .atomic_t { t.atomic_typename() } else { g.cc_type(t, true) }
+	return styp
+}
 
 pub fn (mut g JsGen) typ(t ast.Type) string {
 	sym := g.table.get_final_type_symbol(t)

vlib/v/gen/js/fn.v

@@ -106,7 +106,7 @@ fn (mut g JsGen) method_call(node ast.CallExpr) {
 		g.inc_indent()
 		g.writeln('try {')
 		g.inc_indent()
-		g.write('return builtin.unwrap(')
+		g.write('return unwrap(')
 	}
 	if node.name == 'str' {
 		mut rec_type := node.receiver_type

vlib/v/gen/js/infix.v

@@ -8,7 +8,8 @@ fn (mut g JsGen) gen_plain_infix_expr(node ast.InfixExpr) {
 	l_sym := g.table.get_final_type_symbol(it.left_type)
 	r_sym := g.table.get_final_type_symbol(it.right_type)
 	greater_typ := g.greater_typ(it.left_type, it.right_type)
-	g.write('new ${g.typ(greater_typ)}( ')
+	cast_ty := if greater_typ == it.left_type { l_sym.cname } else { r_sym.cname }
+	g.write('new ${g.js_name(cast_ty)}( ')
 	g.cast_stack << greater_typ
 	if (l_sym.kind == .i64 || l_sym.kind == .u64) || (r_sym.kind == .i64 || r_sym.kind == .u64) {
 		g.write('BigInt(')

vlib/v/gen/js/js.v

@@ -1398,7 +1398,7 @@ fn (mut g JsGen) gen_expr_stmt_no_semi(it ast.ExprStmt) {
 
 // cc_type whether to prefix 'struct' or not (C__Foo -> struct Foo)
 fn (mut g JsGen) cc_type(typ ast.Type, is_prefix_struct bool) string {
-	sym := g.table.get_final_type_symbol(g.unwrap_generic(typ))
+	sym := g.table.get_type_symbol(g.unwrap_generic(typ))
 	mut styp := sym.cname
 	match mut sym.info {
 		ast.Struct, ast.Interface, ast.SumType {
@@ -2306,10 +2306,10 @@ fn (mut g JsGen) gen_index_expr(expr ast.IndexExpr) {
 	left_typ := g.table.get_type_symbol(expr.left_type)
 	// TODO: Handle splice setting if it's implemented
 	if expr.index is ast.RangeExpr {
-		if left_typ.kind == .array {
-			g.write('array_slice(')
-		} else {
+		if left_typ.kind == .string {
 			g.write('string_slice(')
+		} else {
+			g.write('array_slice(')
 		}
 		g.expr(expr.left)
 		if expr.left_type.is_ptr() {