fixes eq for arrays with unspecified size

compiler/src/expression/relational/eq.rs

@@ -57,6 +57,11 @@ pub fn evaluate_eq<'a, F: PrimeField, G: GroupType<F>, CS: ConstraintSystem<F>>(
         }
         (ConstrainedValue::Array(arr_1), ConstrainedValue::Array(arr_2)) => {
             let mut current = ConstrainedValue::Boolean(Boolean::constant(true));
+
+            if arr_1.len() != arr_2.len() {
+                return Err(CompilerError::array_sizes_must_match_in_eq(arr_1.len(), arr_2.len(), span).into());
+            }
+
             for (i, (left, right)) in arr_1.into_iter().zip(arr_2.into_iter()).enumerate() {
                 let next = evaluate_eq(&mut cs.ns(|| format!("array[{}]", i)), left, right, span)?;
 

errors/src/compiler/compiler_errors.rs

@@ -163,7 +163,7 @@ create_errors!(
         help: None,
     }
 
-    /// For when the operation has no implmentation on the type of variable received.
+    /// For when the operation has no implementation on the type of variable received.
     @formatted
     incompatible_types {
         args: (operation: impl Display),
@@ -841,4 +841,11 @@ create_errors!(
         msg: "len() can only be called on an array value".to_string(),
         help: None,
     }
+
+    @formatted
+    array_sizes_must_match_in_eq {
+        args: (lhs: impl Display, rhs: impl Display),
+        msg: format!("array sizes must match for comparison; left: {}, right: {}", lhs, rhs),
+        help: None,
+    }
 );

tests/compiler/array_without_size/compare_fail.leo

@@ -0,0 +1,9 @@
+/*
+namespace: Compile
+expectation: Fail
+*/
+
+function main() {
+    let x: [u8; _] = [1u8,2];
+    let z: bool = x == [1u8,2,3]; // array size mismatch
+}

tests/expectations/compiler/compiler/array_without_size/compare_fail.leo.out

@@ -0,0 +1,5 @@
+---
+namespace: Compile
+expectation: Fail
+outputs:
+  - "Error [ECMP0376093]: array sizes must match for comparison; left: 2, right: 3\n    --> compiler-test:5:19\n     |\n   5 |     let z: bool = x == [1u8,2,3]; // array size mismatch\n     |                   ^^^^^^^^^^^^^^"