Merge pull request #1185 from AleoHQ/bug/ternary-different-types

[Bugfix] Ternary Type Check

asg/src/error/mod.rs

@@ -204,6 +204,12 @@ impl AsgConvertError {
         Self::new_from_span(format!("array index out of bounds: '{}'", index), span)
     }
 
+    pub fn ternary_different_types(left: &str, right: &str, span: &Span) -> Self {
+        let message = format!("ternary sides had different types: left {}, right {}", left, right);
+
+        Self::new_from_span(message, span)
+    }
+
     pub fn unknown_array_size(span: &Span) -> Self {
         Self::new_from_span("array size cannot be inferred, add explicit types".to_string(), span)
     }

asg/src/expression/ternary.rs

@@ -79,6 +79,24 @@ impl<'a> FromAst<'a, leo_ast::TernaryExpression> for TernaryExpression<'a> {
         value: &leo_ast::TernaryExpression,
         expected_type: Option<PartialType<'a>>,
     ) -> Result<TernaryExpression<'a>, AsgConvertError> {
+        let if_true = Cell::new(<&Expression<'a>>::from_ast(
+            scope,
+            &*value.if_true,
+            expected_type.clone(),
+        )?);
+        let left: PartialType = if_true.get().get_type().unwrap().into();
+
+        let if_false = Cell::new(<&Expression<'a>>::from_ast(scope, &*value.if_false, expected_type)?);
+        let right = if_false.get().get_type().unwrap().into();
+
+        if left != right {
+            return Err(AsgConvertError::ternary_different_types(
+                &left.to_string(),
+                &right.to_string(),
+                &value.span,
+            ));
+        }
+
         Ok(TernaryExpression {
             parent: Cell::new(None),
             span: Some(value.span.clone()),
@@ -87,12 +105,8 @@ impl<'a> FromAst<'a, leo_ast::TernaryExpression> for TernaryExpression<'a> {
                 &*value.condition,
                 Some(Type::Boolean.partial()),
             )?),
-            if_true: Cell::new(<&Expression<'a>>::from_ast(
-                scope,
-                &*value.if_true,
-                expected_type.clone(),
-            )?),
-            if_false: Cell::new(<&Expression<'a>>::from_ast(scope, &*value.if_false, expected_type)?),
+            if_true,
+            if_false,
         })
     }
 }

tests/compiler/statements/assign_ternary.leo

@@ -0,0 +1,9 @@
+/*
+namespace: Compile
+expectation: Fail
+input_file: inputs/u32_3.in
+*/
+
+function main(x: u32) {
+    let x = true ? x: true;
+}

tests/expectations/compiler/compiler/statements/assign_ternary.leo.out

@@ -0,0 +1,5 @@
+---
+namespace: Compile
+expectation: Fail
+outputs:
+  - "    --> compiler-test:4:13\n     |\n   4 |     let x = true ? x: true;\n     |             ^^^^^^^^^^^^^^\n     |\n     = ternary sides had different types: left u32, right bool"