From 7878bad95e711cdce08319188e7a199a5ada9c34 Mon Sep 17 00:00:00 2001
From: yuyi <yuyi98@163.com>
Date: Fri, 11 Jun 2021 02:34:36 +0800
Subject: [PATCH] checker: check array type mismatch of array append (#10405)

---
 vlib/v/checker/check_types.v                               | 7 +++++++
 vlib/v/checker/checker.v                                   | 2 +-
 .../checker/tests/array_append_array_type_mismatch_err.out | 7 +++++++
 .../checker/tests/array_append_array_type_mismatch_err.vv  | 5 +++++
 4 files changed, 20 insertions(+), 1 deletion(-)
 create mode 100644 vlib/v/checker/tests/array_append_array_type_mismatch_err.out
 create mode 100644 vlib/v/checker/tests/array_append_array_type_mismatch_err.vv

diff --git a/vlib/v/checker/check_types.v b/vlib/v/checker/check_types.v
index 1c8874f486..524cc1f375 100644
--- a/vlib/v/checker/check_types.v
+++ b/vlib/v/checker/check_types.v
@@ -331,6 +331,13 @@ pub fn (mut c Checker) check_types(got ast.Type, expected ast.Type) bool {
 	return true
 }
 
+fn (mut c Checker) check_array_value_types(got ast.Type, expected ast.Type) bool {
+	if expected.is_number() && got.is_number() && expected != c.table.mktyp(got) {
+		return false
+	}
+	return c.check_types(got, expected)
+}
+
 pub fn (mut c Checker) check_expected(got ast.Type, expected ast.Type) ? {
 	if c.check_types(got, expected) {
 		return
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index a6456c2322..56047d34f2 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -1242,7 +1242,7 @@ pub fn (mut c Checker) infix_expr(mut node ast.InfixExpr) ast.Type {
 					return ast.void_type
 				}
 				if right_final.kind == .array
-					&& c.check_types(left_value_type, c.table.value_type(right_type)) {
+					&& c.check_array_value_types(left_value_type, c.table.value_type(right_type)) {
 					// []T << []T
 					return ast.void_type
 				}
diff --git a/vlib/v/checker/tests/array_append_array_type_mismatch_err.out b/vlib/v/checker/tests/array_append_array_type_mismatch_err.out
new file mode 100644
index 0000000000..0cd37f3d75
--- /dev/null
+++ b/vlib/v/checker/tests/array_append_array_type_mismatch_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/array_append_array_type_mismatch_err.vv:3:8: error: cannot append `[]int` to `[]byte`
+    1 | fn main() {
+    2 |     mut bc := []byte{}
+    3 |     bc << [0xCA, 0xFE, 0xBA, 0xBE]
+      |           ~~~~~~~~~~~~~~~~~~~~~~~~
+    4 |     println(bc)
+    5 | }
diff --git a/vlib/v/checker/tests/array_append_array_type_mismatch_err.vv b/vlib/v/checker/tests/array_append_array_type_mismatch_err.vv
new file mode 100644
index 0000000000..45de913508
--- /dev/null
+++ b/vlib/v/checker/tests/array_append_array_type_mismatch_err.vv
@@ -0,0 +1,5 @@
+fn main() {
+	mut bc := []byte{}
+	bc << [0xCA, 0xFE, 0xBA, 0xBE]
+	println(bc)
+}