test: Showcase warning detection false positives

test/bin/mdx-test/expect/warnings/test-case.md

@@ -29,3 +29,36 @@ Warning 9 [missing-record-field-pattern]: the following labels are not bound in
 y
 Either bind these labels explicitly or add '; _' to the pattern.
 ```
+
+Test against some false positives:
+
+```ocaml
+let x = [ "Warning" ]
+```
+```mdx-error
+val x : string list = ["Warning"]
+```
+
+```ocaml
+module Warning = struct
+  type t = Warning
+end
+
+let warning = Warning.Warning
+```
+```mdx-error
+module Warning : sig type t = Warning end
+val warning : Warning.t = Warning.Warning
+```
+
+Intended false positive:
+
+```ocaml
+let x =
+  if true then
+    prerr_endline "Warning: Assert failed";
+  [ "foo" ]
+```
+```mdx-error
+Warning: Assert failed
+```