From a1aa5326ad0ac941dded6d51550c2889c530f0be Mon Sep 17 00:00:00 2001
From: damirka <damirka.ru@gmail.com>
Date: Tue, 28 Sep 2021 11:09:56 +0300
Subject: [PATCH] fixes eq for arrays with unspecified size

---
 compiler/src/expression/relational/eq.rs                 | 5 +++++
 errors/src/compiler/compiler_errors.rs                   | 9 ++++++++-
 tests/compiler/array_without_size/compare_fail.leo       | 9 +++++++++
 .../compiler/array_without_size/compare_fail.leo.out     | 5 +++++
 4 files changed, 27 insertions(+), 1 deletion(-)
 create mode 100644 tests/compiler/array_without_size/compare_fail.leo
 create mode 100644 tests/expectations/compiler/compiler/array_without_size/compare_fail.leo.out

diff --git a/compiler/src/expression/relational/eq.rs b/compiler/src/expression/relational/eq.rs
index 3fea711e53..7cd39de84f 100644
--- a/compiler/src/expression/relational/eq.rs
+++ b/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)?;
 
diff --git a/errors/src/compiler/compiler_errors.rs b/errors/src/compiler/compiler_errors.rs
index c66358a068..ede090dcdf 100644
--- a/errors/src/compiler/compiler_errors.rs
+++ b/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,
+    }
 );
diff --git a/tests/compiler/array_without_size/compare_fail.leo b/tests/compiler/array_without_size/compare_fail.leo
new file mode 100644
index 0000000000..2aa1ce8360
--- /dev/null
+++ b/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
+}
diff --git a/tests/expectations/compiler/compiler/array_without_size/compare_fail.leo.out b/tests/expectations/compiler/compiler/array_without_size/compare_fail.leo.out
new file mode 100644
index 0000000000..f3e1a96589
--- /dev/null
+++ b/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     |                   ^^^^^^^^^^^^^^"