Fix bug with empty arrays in match (#207)

air/src/execution_step/air/compare_matchable/comparator.rs

@@ -47,6 +47,11 @@ pub(crate) fn are_matchable_eq<'ctx>(
             compare_matchable(matchable, exec_ctx, make_string_comparator(value))
         }
 
+        (EmptyArray, EmptyArray) => Ok(true),
+        (EmptyArray, matchable) | (matchable, EmptyArray) => {
+            compare_matchable(matchable, exec_ctx, make_object_comparator(JValue::Array(vec![])))
+        }
+
         (Boolean(left_boolean), Boolean(right_boolean)) => Ok(left_boolean == right_boolean),
         (Boolean(value), matchable) | (matchable, Boolean(value)) => {
             compare_matchable(matchable, exec_ctx, make_object_comparator((*value).into()))
@@ -63,7 +68,6 @@ pub(crate) fn are_matchable_eq<'ctx>(
 
             Ok(left_value == right_value)
         }
-        _ => Ok(false),
     }
 }
 

air/tests/test_module/issues/issue_206.rs

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2021 Fluence Labs Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+use air_test_utils::prelude::*;
+
+use fstrings::f;
+use fstrings::format_args_f;
+
+#[test]
+// test for github.com/fluencelabs/aquavm/issues/206
+fn issue_206() {
+    let peer_1_id = "peer_1_id";
+    let mut peer_1 = create_avm(echo_call_service(), peer_1_id);
+
+    let script = f!(r#"
+    (new $result
+        (seq
+            (xor
+                (match $result []
+                    (xor
+                        (ap "is nil" $result)
+                        (call %init_peer_id% ("errorHandlingSrv" "error") [%last_error% 1])
+                    )
+                )
+                (ap "not" $result)
+            )
+            (call %init_peer_id% ("op" "identity") [$result] result-fix)
+        )
+    )
+    "#);
+
+    let result = checked_call_vm!(peer_1, peer_1_id, &script, "", "");
+
+    let actual_trace = trace_from_result(&result);
+    let expected_trace = vec![executed_state::ap(Some(0)), executed_state::scalar(json!(["is nil"]))];
+    assert_eq!(actual_trace, expected_trace);
+}

air/tests/test_module/issues/mod.rs

@@ -19,3 +19,4 @@ mod issue_173;
 mod issue_177;
 mod issue_178;
 mod issue_180;
+mod issue_206;