Add test for duplicate variant check

schala-lang/language/src/symbol_table/mod.rs

@@ -1,4 +1,4 @@
-use std::collections::{hash_map::Entry, HashMap};
+use std::collections::{hash_map::Entry, HashMap, HashSet};
 use std::fmt;
 use std::rc::Rc;
 
@@ -85,6 +85,10 @@ pub enum SymbolError {
         prev_name: Fqsn,
         location: Location,
     },
+    DuplicateVariant {
+        type_fqsn: Fqsn,
+        name: String,
+    },
     DuplicateRecord {
         type_name: Fqsn,
         location: Location,
@@ -486,6 +490,30 @@ impl<'a> SymbolTableRunner<'a> {
         location: Location,
         scope_stack: &mut Vec<Scope>,
     ) -> Vec<SymbolError> {
+
+        let type_fqsn = Fqsn::from_scope_stack(scope_stack, type_name.name.clone());
+
+        let TypeBody(variants) = type_body;
+        let mut duplicates = HashSet::new();
+        let mut dup_errors = vec![];
+
+        for variant in variants {
+            if duplicates.contains(&variant.name) {
+                dup_errors.push(SymbolError::DuplicateVariant {
+                    type_fqsn: type_fqsn.clone(),
+                    name: variant.name.as_ref().to_string()
+                })
+            }
+            duplicates.insert(variant.name.clone());
+        }
+
+        if !dup_errors.is_empty() {
+            return dup_errors;
+        }
+
+
+
+
         let mut member_errors = vec![];
         let mut errors = vec![];
 
@@ -501,7 +529,6 @@ impl<'a> SymbolTableRunner<'a> {
             };
         };
 
-        let TypeBody(variants) = type_body;
         let new_scope = Scope::Name(type_name.name.clone());
         scope_stack.push(new_scope);
 

schala-lang/language/src/symbol_table/test.rs

@@ -89,6 +89,23 @@ fn no_type_definition_duplicates() {
     }
 }
 
+#[test]
+fn no_variant_duplicates() {
+    let source = r#"
+type Panda = FoolsGold | Kappa(i32) | Remix | Kappa | Thursday | Remix
+"#;
+    let (_, output) = add_symbols(source);
+    let errs = output.unwrap_err();
+    assert_eq!(errs.len(), 2);
+    assert_matches!(&errs[0], SymbolError::DuplicateVariant {
+        type_fqsn, name } if *type_fqsn == Fqsn::from_strs(&["Panda"]) &&
+        name == "Kappa");
+
+    assert_matches!(&errs[1], SymbolError::DuplicateVariant {
+        type_fqsn, name } if *type_fqsn == Fqsn::from_strs(&["Panda"]) &&
+        name == "Remix");
+}
+
 #[test]
 fn no_variable_definition_duplicates_in_function() {
     let source = r#"