From 7c291158c2c48052467816fd5f2b563c214ac9df Mon Sep 17 00:00:00 2001
From: John David Pressman <jd@jdpressman.com>
Date: Wed, 6 Nov 2019 11:08:18 -0800
Subject: [PATCH] Finish balance operator and add test for CameLIGO

---
 src/passes/operators/operators.ml         |  2 ++
 src/test/contracts/balance_constant.mligo | 17 +++++++++++++++++
 src/test/integration_tests.ml             |  7 +++++++
 3 files changed, 26 insertions(+)
 create mode 100644 src/test/contracts/balance_constant.mligo

diff --git a/src/passes/operators/operators.ml b/src/passes/operators/operators.ml
index 04db39706..ac4d68bfc 100644
--- a/src/passes/operators/operators.ml
+++ b/src/passes/operators/operators.ml
@@ -751,6 +751,7 @@ module Typer = struct
       sender ;
       source ;
       unit ;
+      balance ;
       amount ;
       transaction ;
       get_contract ;
@@ -827,6 +828,7 @@ module Compiler = struct
     ("ABS" , simple_unary @@ prim I_ABS) ;
     ("CONS" , simple_binary @@ prim I_CONS) ;
     ("UNIT" , simple_constant @@ prim I_UNIT) ;
+    ("BALANCE" , simple_constant @@ prim I_BALANCE) ;
     ("AMOUNT" , simple_constant @@ prim I_AMOUNT) ;
     ("ADDRESS" , simple_constant @@ prim I_ADDRESS) ;
     ("NOW" , simple_constant @@ prim I_NOW) ;
diff --git a/src/test/contracts/balance_constant.mligo b/src/test/contracts/balance_constant.mligo
new file mode 100644
index 000000000..8ac584a40
--- /dev/null
+++ b/src/test/contracts/balance_constant.mligo
@@ -0,0 +1,17 @@
+(**
+
+This test makes sure that the balance is accessible in CameLIGO.
+It's there to detect a regression of: https://gitlab.com/ligolang/ligo/issues/61
+
+Which results in this error when you attempt to compile this contract:
+
+generated. unrecognized constant: {"constant":"BALANCE","location":"generated"}
+
+
+*)
+
+type storage = tez
+
+let main (p : unit) storage =
+  ([] : operation list), balance
+
diff --git a/src/test/integration_tests.ml b/src/test/integration_tests.ml
index f670f11c6..a971527aa 100644
--- a/src/test/integration_tests.ml
+++ b/src/test/integration_tests.ml
@@ -1150,6 +1150,12 @@ let website2_mligo () : unit result =
     e_pair (e_typed_list [] t_operation) (e_int (op 42 n)) in
   expect_eq_n program "main" make_input make_expected
 
+let balance_constant () : unit result =
+  let%bind program = mtype_file "./contracts/balance_constant.mligo" in
+  let input = e_tuple [e_unit () ; e_mutez 0]  in
+  let expected = e_tuple [e_list []; e_mutez 4000000000000] in
+  expect_eq program "main" input expected
+
 let main = test_suite "Integration (End to End)" [
     test "type alias" type_alias ;
     test "function" function_ ;
@@ -1230,4 +1236,5 @@ let main = test_suite "Integration (End to End)" [
     test "website1 ligo" website1_ligo ;
     test "website2 ligo" website2_ligo ;
     test "website2 (mligo)" website2_mligo ;
+    test "balance constant (mligo)" balance_constant ;
   ]