iter 23.2.3: prelude — class Eq a + Eq Int/Bool/Str instances

crates/ailang-core/src/workspace.rs

@@ -920,6 +920,42 @@ mod tests {
             )),
             "prelude must contain Ordering type def"
         );
+
+        // Iter 23.2: prelude also ships the `Eq` class plus three
+        // primitive instances (Eq Int, Eq Bool, Eq Str).
+        assert!(
+            prelude.defs.iter().any(|d| matches!(
+                d,
+                crate::ast::Def::Class(c) if c.name == "Eq"
+            )),
+            "prelude must contain Eq class def"
+        );
+        let eq_instance_types: Vec<&str> = prelude
+            .defs
+            .iter()
+            .filter_map(|d| match d {
+                crate::ast::Def::Instance(i) if i.class == "Eq" => {
+                    if let crate::ast::Type::Con { name, .. } = &i.type_ {
+                        Some(name.as_str())
+                    } else {
+                        None
+                    }
+                }
+                _ => None,
+            })
+            .collect();
+        assert!(
+            eq_instance_types.contains(&"Int"),
+            "prelude must contain `instance Eq Int`; saw Eq instances on: {eq_instance_types:?}"
+        );
+        assert!(
+            eq_instance_types.contains(&"Bool"),
+            "prelude must contain `instance Eq Bool`; saw Eq instances on: {eq_instance_types:?}"
+        );
+        assert!(
+            eq_instance_types.contains(&"Str"),
+            "prelude must contain `instance Eq Str`; saw Eq instances on: {eq_instance_types:?}"
+        );
     }
 
     #[test]