iter 22b.3.6: call-site rewrite — same/cross module qualified names

crates/ail/tests/typeclass_22b3.rs

@@ -442,3 +442,37 @@ fn fixpoint_handles_chained_class_method_calls() {
          — multi-round fixpoint property"
     );
 }
+
+/// After the mono pass, the body of `main` in
+/// test_22b2_instance_present must reference `show#Int` instead
+/// of `show`.
+#[test]
+fn rewrite_replaces_class_method_var_with_mono_symbol_same_module() {
+    let entry = examples_dir().join("test_22b2_instance_present.ail.json");
+    let ws = ailang_core::load_workspace(&entry).expect("load");
+    let diags = ailang_check::check_workspace(&ws);
+    assert!(diags.is_empty(), "fixture must typecheck: {:?}", diags);
+
+    let ws = ailang_check::monomorphise_workspace(&ws).expect("mono");
+
+    let main_module = ws.modules.get("test_22b2_instance_present").unwrap();
+    let main_fn = main_module
+        .defs
+        .iter()
+        .find_map(|d| match d {
+            ailang_core::ast::Def::Fn(f) if f.name == "main" => Some(f),
+            _ => None,
+        })
+        .expect("main");
+
+    // The body is `App { fn: Var "show", args: [Lit 42] }`. After
+    // rewrite, the callee Var must be `show#Int`.
+    let callee_name: &str = match &main_fn.body {
+        ailang_core::ast::Term::App { callee, .. } => match callee.as_ref() {
+            ailang_core::ast::Term::Var { name } => name.as_str(),
+            other => panic!("callee is not Var: {:?}", other),
+        },
+        other => panic!("body is not App: {:?}", other),
+    };
+    assert_eq!(callee_name, "show#Int");
+}