checker: fix match expr type mismatch (#11220)

Author: yuyi98

vlib/v/checker/checker.v

@@ -6091,7 +6091,8 @@ pub fn (mut c Checker) match_expr(mut node ast.MatchExpr) ast.Type {
 						}
 						stmt.typ = expr_type
 					} else if node.is_expr && ret_type != expr_type {
-						if !c.check_types(ret_type, expr_type) {
+						if !c.check_types(ret_type, expr_type)
+							&& !c.check_types(expr_type, ret_type) {
 							ret_sym := c.table.get_type_symbol(ret_type)
 							if !(node.is_expr && ret_sym.kind == .sum_type) {
 								c.error('return type mismatch, it should be `$ret_sym.name`',

vlib/v/checker/tests/if_match_expr.out

@@ -40,10 +40,3 @@ vlib/v/checker/tests/if_match_expr.vv:23:3: error: `match` expression branch has
       |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    24 |         _ = match true {true {1} else {-1}} // OK
    25 |         match true {true {1} else {-1}} // result
-vlib/v/checker/tests/if_match_expr.vv:25:3: error: return type mismatch, it should be `int`
-   23 |         match true {true {} else {}} // statement not expression
-   24 |         _ = match true {true {1} else {-1}} // OK
-   25 |         match true {true {1} else {-1}} // result
-      |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-   26 |     }
-   27 | }

vlib/v/tests/match_expr_with_promote_number_test.v

@@ -0,0 +1,34 @@
+struct Data {
+	x f64
+	y f64
+}
+
+fn (d Data) test(n int) f64 {
+	return match n {
+		0 { d.x }
+		1 { d.y }
+		else { 0 }
+	}
+}
+
+fn test1(n int) f64 {
+	return match n {
+		0 { 1 }
+		1 { 2 }
+		else { 0 }
+	}
+}
+
+fn test_match_expr_with_promote_number() {
+	d := Data{
+		x: 1
+		y: 2
+	}
+	ret1 := d.test(2)
+	println(ret1)
+	assert ret1 == 0
+
+	ret2 := test1(2)
+	println(ret2)
+	assert ret2 == 0
+}