jsgen: fix map to string fails on rune keys (fix #24637) (#24638)

Author: gchumillas

vlib/v/gen/js/builtin_types.v

@@ -456,7 +456,7 @@ fn (mut g JsGen) gen_builtin_type_defs() {
 					value_of:      'this.val | 0'
 					to_string:     'new string(this.val + "")'
 					eq:            'new bool(self.valueOf() === other.valueOf())'
-					to_jsval:      '+this'
+					to_jsval:      'String.fromCharCode(+this)'
 				)
 			}
 			'f32', 'f64', 'float_literal' {

vlib/v/gen/js/js.v

@@ -900,11 +900,7 @@ fn (mut g JsGen) expr(node_ ast.Expr) {
 			// TODO
 		}
 		ast.CharLiteral {
-			if !node.val.is_pure_ascii() {
-				g.write("new rune('${node.val}'.charCodeAt())")
-			} else {
-				g.write("new u8('${node.val}')")
-			}
+			g.write("new rune('${node.val}')")
 		}
 		ast.Comment {}
 		ast.ComptimeCall {
@@ -1712,8 +1708,12 @@ fn (mut g JsGen) gen_for_in_stmt(it ast.ForInStmt) {
 
 			g.inc_indent()
 			g.writeln('let ${val} = ${tmp}.map[${tmp2}];')
-			g.writeln('let ${key} = ${tmp2};')
-
+			sym := g.table.sym(it.key_type)
+			if sym.is_number() {
+				g.writeln('let ${key} = new ${g.styp(it.key_type)}(+${tmp2})')
+			} else {
+				g.writeln('let ${key} = new ${g.styp(it.key_type)}(${tmp2})')
+			}
 			g.writeln('try { ')
 			g.inc_indent()
 			g.stmts(it.stmts)

vlib/v/gen/js/tests/map.v

@@ -226,11 +226,25 @@ fn test_map_len() {
 	assert items_2.len == 2
 }
 
+fn test_rune_keys() {
+	mut m := {
+		`!`: 2
+		`%`: 3
+	}
+	assert typeof(m).name == 'map[rune]int'
+	assert m[`!`] == 2
+	m[`@`] = 7
+	assert m.len == 3
+	println(m)
+	assert '${m}' == '{`!`: 2, `%`: 3, `@`: 7}'
+}
+
 fn main() {
 	test_values_method()
 	test_values_method_with_generic_constraints()
 	test_keys_method()
 	test_keys_method_with_generic_constraints()
 	test_direct_map_access()
 	test_map_len()
+	test_rune_keys()
 }