checker: fix missing check for unwrapped shift operation (#18451)

Author: felipensp

vlib/v/checker/infix.v

@@ -457,7 +457,7 @@ fn (mut c Checker) infix_expr(mut node ast.InfixExpr) ast.Type {
 			} else if node.left !in [ast.Ident, ast.SelectorExpr, ast.ComptimeSelector]
 				&& (left_type.has_flag(.option) || right_type.has_flag(.option)) {
 				opt_comp_pos := if left_type.has_flag(.option) { left_pos } else { right_pos }
-				c.error('unwrapped option cannot be compared in an infix expression',
+				c.error('unwrapped Option cannot be compared in an infix expression',
 					opt_comp_pos)
 			}
 		}
@@ -471,6 +471,11 @@ fn (mut c Checker) infix_expr(mut node ast.InfixExpr) ast.Type {
 				if !node.is_stmt {
 					c.error('array append cannot be used in an expression', node.pos)
 				}
+				if left_type.has_flag(.option) && node.left is ast.Ident
+					&& (node.left as ast.Ident).or_expr.kind == .absent {
+					c.error('unwrapped Option cannot be used in an infix expression',
+						node.pos)
+				}
 				// `array << elm`
 				c.check_expr_opt_call(node.right, right_type)
 				node.auto_locked, _ = c.fail_if_immutable(node.left)
@@ -695,15 +700,15 @@ fn (mut c Checker) infix_expr(mut node ast.InfixExpr) ast.Type {
 		opt_infix_pos := if left_is_option { left_pos } else { right_pos }
 		if (node.left !in [ast.Ident, ast.SelectorExpr, ast.ComptimeSelector]
 			|| node.op in [.eq, .ne, .lt, .gt, .le, .ge]) && right_sym.kind != .none_ {
-			c.error('unwrapped option cannot be used in an infix expression', opt_infix_pos)
+			c.error('unwrapped Option cannot be used in an infix expression', opt_infix_pos)
 		}
 	}
 
 	left_is_result := left_type.has_flag(.result)
 	right_is_result := right_type.has_flag(.result)
 	if left_is_result || right_is_result {
 		opt_infix_pos := if left_is_result { left_pos } else { right_pos }
-		c.error('unwrapped result cannot be used in an infix expression', opt_infix_pos)
+		c.error('unwrapped Result cannot be used in an infix expression', opt_infix_pos)
 	}
 
 	// Dual sides check (compatibility check)

vlib/v/checker/tests/infix_compare_option_err.out

@@ -1,7 +1,7 @@
-vlib/v/checker/tests/infix_compare_option_err.vv:6:5: error: unwrapped option cannot be compared in an infix expression
-    4 |
+vlib/v/checker/tests/infix_compare_option_err.vv:6:5: error: unwrapped Option cannot be compared in an infix expression
+    4 | 
     5 | fn main() {
     6 |     if foo() > foo() {
       |        ~~~~~
     7 |     }
-    8 | }
+    8 | }

vlib/v/checker/tests/infix_err.out

@@ -17,17 +17,17 @@ vlib/v/checker/tests/infix_err.vv:9:9: error: `+` cannot be used with `?string`
     8 | _ = f() + ''
     9 | _ = f() + f()
       |         ^
-   10 |
+   10 | 
    11 | _ = 4 + g()
 vlib/v/checker/tests/infix_err.vv:11:7: error: `+` cannot be used with `?int`
     9 | _ = f() + f()
-   10 |
+   10 | 
    11 | _ = 4 + g()
       |       ^
    12 | _ = int(0) + g() // FIXME not detected
    13 | _ = g() + int(3)
-vlib/v/checker/tests/infix_err.vv:12:14: error: unwrapped option cannot be used in an infix expression
-   10 |
+vlib/v/checker/tests/infix_err.vv:12:14: error: unwrapped Option cannot be used in an infix expression
+   10 | 
    11 | _ = 4 + g()
    12 | _ = int(0) + g() // FIXME not detected
       |              ~~~
@@ -45,10 +45,10 @@ vlib/v/checker/tests/infix_err.vv:14:9: error: `+` cannot be used with `?int`
    13 | _ = g() + int(3)
    14 | _ = g() + 3
       |         ^
-   15 |
+   15 | 
    16 | // binary operands
 vlib/v/checker/tests/infix_err.vv:17:5: error: left operand for `&&` is not a boolean
-   15 |
+   15 | 
    16 | // binary operands
    17 | _ = 1 && 2
       |     ^
@@ -59,10 +59,10 @@ vlib/v/checker/tests/infix_err.vv:18:13: error: right operand for `||` is not a
    17 | _ = 1 && 2
    18 | _ = true || 2
       |             ^
-   19 |
+   19 | 
    20 | // boolean expressions
 vlib/v/checker/tests/infix_err.vv:21:22: error: ambiguous boolean expression. use `()` to ensure correct order of operations
-   19 |
+   19 | 
    20 | // boolean expressions
    21 | _ = 1 == 1 && 2 == 2 || 3 == 3
       |                      ~~
@@ -78,4 +78,4 @@ vlib/v/checker/tests/infix_err.vv:24:2: error: ambiguous boolean expression. use
    22 | _ = 1 == 1
    23 |     && 2 == 2 || 3 == 3
    24 |     && 4 == 4
-      |     ~~
+      |     ~~

vlib/v/checker/tests/option_wrapped_cmp_op_err.out

@@ -1,25 +1,25 @@
-vlib/v/checker/tests/option_wrapped_cmp_op_err.vv:3:10: error: unwrapped option cannot be used in an infix expression
+vlib/v/checker/tests/option_wrapped_cmp_op_err.vv:3:10: error: unwrapped Option cannot be used in an infix expression
     1 | fn main() {
     2 |     a := ?string("hi")
     3 |     println(a == 'hi')
       |             ^
     4 |     println('hi' == a)
     5 |     println(a != 'hi')
-vlib/v/checker/tests/option_wrapped_cmp_op_err.vv:4:18: error: unwrapped option cannot be used in an infix expression
+vlib/v/checker/tests/option_wrapped_cmp_op_err.vv:4:18: error: unwrapped Option cannot be used in an infix expression
     2 |     a := ?string("hi")
     3 |     println(a == 'hi')
     4 |     println('hi' == a)
       |                     ^
     5 |     println(a != 'hi')
     6 |     println('hi' != a)
-vlib/v/checker/tests/option_wrapped_cmp_op_err.vv:5:10: error: unwrapped option cannot be used in an infix expression
+vlib/v/checker/tests/option_wrapped_cmp_op_err.vv:5:10: error: unwrapped Option cannot be used in an infix expression
     3 |     println(a == 'hi')
     4 |     println('hi' == a)
     5 |     println(a != 'hi')
       |             ^
     6 |     println('hi' != a)
     7 | }
-vlib/v/checker/tests/option_wrapped_cmp_op_err.vv:6:18: error: unwrapped option cannot be used in an infix expression
+vlib/v/checker/tests/option_wrapped_cmp_op_err.vv:6:18: error: unwrapped Option cannot be used in an infix expression
     4 |     println('hi' == a)
     5 |     println(a != 'hi')
     6 |     println('hi' != a)

vlib/v/checker/tests/unwrapped_option_infix.out

@@ -1,5 +1,5 @@
-vlib/v/checker/tests/unwrapped_option_infix.vv:5:9: error: unwrapped option cannot be used in an infix expression
+vlib/v/checker/tests/unwrapped_option_infix.vv:5:9: error: unwrapped Option cannot be used in an infix expression
     3 | }
-    4 |
+    4 | 
     5 | println(test() == '')
-      |         ~~~~~~
+      |         ~~~~~~

vlib/v/checker/tests/unwrapped_result_infix_err.out

@@ -1,8 +1,7 @@
-vlib/v/checker/tests/unwrapped_result_infix_err.vv:7:9: error: unwrapped result cannot be used in an infix expression
+vlib/v/checker/tests/unwrapped_result_infix_err.vv:7:9: error: unwrapped Result cannot be used in an infix expression
     5 | fn g() ! {
     6 |     assert f('1')! == true
     7 |     assert f('1') == true
       |            ~~~~~~
     8 | }
     9 |
-

vlib/v/checker/tests/wrong_shift_left_option_err.out

@@ -0,0 +1,14 @@
+vlib/v/checker/tests/wrong_shift_left_option_err.vv:7:4: error: unwrapped Option cannot be used in an infix expression
+    5 | fn main() {
+    6 |     mut a := ?[]SomeStruct([SomeStruct{}, SomeStruct{}]) // struct type
+    7 |     a << []SomeStruct{len: 20}
+      |       ~~
+    8 |     mut b := ?[]int([2, 8]) // primitive type
+    9 |     b << [1, 3, 4]
+vlib/v/checker/tests/wrong_shift_left_option_err.vv:9:4: error: unwrapped Option cannot be used in an infix expression
+    7 |     a << []SomeStruct{len: 20}
+    8 |     mut b := ?[]int([2, 8]) // primitive type
+    9 |     b << [1, 3, 4]
+      |       ~~
+   10 |     dump(a?.len)
+   11 |     dump(b)

vlib/v/checker/tests/wrong_shift_left_option_err.vv

@@ -0,0 +1,12 @@
+pub struct SomeStruct {
+	i int
+}
+
+fn main() {
+	mut a := ?[]SomeStruct([SomeStruct{}, SomeStruct{}]) // struct type
+	a << []SomeStruct{len: 20}
+	mut b := ?[]int([2, 8]) // primitive type
+	b << [1, 3, 4]
+	dump(a?.len)
+	dump(b)
+}