From c51f83efba2d0c3c60d165672b6a3f217311e5c8 Mon Sep 17 00:00:00 2001
From: yuyi <yuyi98@163.com>
Date: Wed, 18 Aug 2021 13:52:01 +0800
Subject: [PATCH] checker: fix match expr type mismatch (#11220)

---
 vlib/v/checker/checker.v                      |  3 +-
 vlib/v/checker/tests/if_match_expr.out        |  7 ----
 .../match_expr_with_promote_number_test.v     | 34 +++++++++++++++++++
 3 files changed, 36 insertions(+), 8 deletions(-)
 create mode 100644 vlib/v/tests/match_expr_with_promote_number_test.v

diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index 881bcb694a..1e3eb79caf 100644
--- a/vlib/v/checker/checker.v
+++ b/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`',
diff --git a/vlib/v/checker/tests/if_match_expr.out b/vlib/v/checker/tests/if_match_expr.out
index 9c6597646b..81c13a7f69 100644
--- a/vlib/v/checker/tests/if_match_expr.out
+++ b/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 | }
diff --git a/vlib/v/tests/match_expr_with_promote_number_test.v b/vlib/v/tests/match_expr_with_promote_number_test.v
new file mode 100644
index 0000000000..572cd6d863
--- /dev/null
+++ b/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
+}