From ce2ece667dac76f4aed41b7179ee4262d58c6cba Mon Sep 17 00:00:00 2001
From: Alexander Medvednikov <alexander@medvednikov.com>
Date: Wed, 15 Apr 2026 15:07:00 +0300
Subject: [PATCH] checker: fix missing compile time error for option selector
 in or block (fixes #17761)

---
 ...option_selector_ierror_in_or_block_err.out | 14 ++++++++++++++
 .../option_selector_ierror_in_or_block_err.vv | 19 +++++++++++++++++++
 2 files changed, 33 insertions(+)
 create mode 100644 vlib/v/checker/tests/option_selector_ierror_in_or_block_err.out
 create mode 100644 vlib/v/checker/tests/option_selector_ierror_in_or_block_err.vv

diff --git a/vlib/v/checker/tests/option_selector_ierror_in_or_block_err.out b/vlib/v/checker/tests/option_selector_ierror_in_or_block_err.out
new file mode 100644
index 000000000..f093de4aa
--- /dev/null
+++ b/vlib/v/checker/tests/option_selector_ierror_in_or_block_err.out
@@ -0,0 +1,14 @@
+vlib/v/checker/tests/option_selector_ierror_in_or_block_err.vv:11:15: error: to propagate the call, `check` must return an Option type
+    9 | fn (c SomeStruct) check() int {
+   10 |     some_fn_that_produce_err() or {
+   11 |         assert c.err? == err
+      |                     ^
+   12 |         return 0
+   13 |     }
+Details: vlib/v/checker/tests/option_selector_ierror_in_or_block_err.vv:9:27: details: prepend ? before the declaration of the return type of `check`
+    7 | }
+    8 | 
+    9 | fn (c SomeStruct) check() int {
+      |                           ~~~
+   10 |     some_fn_that_produce_err() or {
+   11 |         assert c.err? == err
diff --git a/vlib/v/checker/tests/option_selector_ierror_in_or_block_err.vv b/vlib/v/checker/tests/option_selector_ierror_in_or_block_err.vv
new file mode 100644
index 000000000..aedae6db3
--- /dev/null
+++ b/vlib/v/checker/tests/option_selector_ierror_in_or_block_err.vv
@@ -0,0 +1,19 @@
+struct SomeStruct {
+	err ?IError
+}
+
+fn some_fn_that_produce_err() ! {
+	return error('hey')
+}
+
+fn (c SomeStruct) check() int {
+	some_fn_that_produce_err() or {
+		assert c.err? == err
+		return 0
+	}
+	return 1
+}
+
+fn main() {
+	SomeStruct{}.check()
+}
-- 
2.39.5