checker: check error for arguments of array.contains() (#14102)

vlib/v/checker/fn.v

@@ -1893,6 +1893,17 @@ fn (mut c Checker) array_builtin_method_call(mut node ast.CallExpr, left_type as
 		node.return_type = ast.void_type
 	} else if method_name == 'contains' {
 		// c.warn('use `value in arr` instead of `arr.contains(value)`', node.pos)
+		if node.args.len != 1 {
+			c.error('`.contains()` expected 1 argument, but got $node.args.len', node.pos)
+		} else {
+			arg_typ := ast.mktyp(c.expr(node.args[0].expr))
+			elem_typ_str := c.table.type_to_str(elem_typ)
+			arg_typ_str := c.table.type_to_str(arg_typ)
+			if !left_sym.has_method('contains') && elem_typ_str != arg_typ_str {
+				c.error('`.contains()` expected `$elem_typ_str` argument, but got `$arg_typ_str`',
+					node.pos)
+			}
+		}
 		node.return_type = ast.bool_type
 	} else if method_name == 'index' {
 		node.return_type = ast.int_type

vlib/v/checker/tests/array_contains_args_err.out

@@ -0,0 +1,35 @@
+vlib/v/checker/tests/array_contains_args_err.vv:3:17: error: `.contains()` expected `int` argument, but got `[]int`
+    1 | fn main() {
+    2 |     arr := [0]
+    3 |     mut ret := [0].contains([0])
+      |                    ~~~~~~~~~~~~~
+    4 |     ret = [0].contains()
+    5 |     ret = [0, 1, 2].contains(0, 1, 2)
+vlib/v/checker/tests/array_contains_args_err.vv:4:12: error: `.contains()` expected 1 argument, but got 0
+    2 |     arr := [0]
+    3 |     mut ret := [0].contains([0])
+    4 |     ret = [0].contains()
+      |               ~~~~~~~~~~
+    5 |     ret = [0, 1, 2].contains(0, 1, 2)
+    6 |     ret = [0].contains('a')
+vlib/v/checker/tests/array_contains_args_err.vv:5:18: error: `.contains()` expected 1 argument, but got 3
+    3 |     mut ret := [0].contains([0])
+    4 |     ret = [0].contains()
+    5 |     ret = [0, 1, 2].contains(0, 1, 2)
+      |                     ~~~~~~~~~~~~~~~~~
+    6 |     ret = [0].contains('a')
+    7 |     ret = [0].contains(arr)
+vlib/v/checker/tests/array_contains_args_err.vv:6:12: error: `.contains()` expected `int` argument, but got `string`
+    4 |     ret = [0].contains()
+    5 |     ret = [0, 1, 2].contains(0, 1, 2)
+    6 |     ret = [0].contains('a')
+      |               ~~~~~~~~~~~~~
+    7 |     ret = [0].contains(arr)
+    8 |     println(ret)
+vlib/v/checker/tests/array_contains_args_err.vv:7:12: error: `.contains()` expected `int` argument, but got `[]int`
+    5 |     ret = [0, 1, 2].contains(0, 1, 2)
+    6 |     ret = [0].contains('a')
+    7 |     ret = [0].contains(arr)
+      |               ~~~~~~~~~~~~~
+    8 |     println(ret)
+    9 | }

vlib/v/checker/tests/array_contains_args_err.vv

@@ -0,0 +1,9 @@
+fn main() {
+	arr := [0]
+	mut ret := [0].contains([0])
+	ret = [0].contains()
+	ret = [0, 1, 2].contains(0, 1, 2)
+	ret = [0].contains('a')
+	ret = [0].contains(arr)
+	println(ret)
+}