diff --git a/src/bin/expect_tests/code_insertion.ml b/src/bin/expect_tests/code_insertion.ml
index 0add86ac0..6962b27cb 100644
--- a/src/bin/expect_tests/code_insertion.ml
+++ b/src/bin/expect_tests/code_insertion.ml
@@ -8,19 +8,21 @@ let bad_contract basename =
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; bad_contract "bad_michelson_insertion_1.ligo" ; "main" ] ;
   [%expect{|
-    ligo: generated Michelson contract failed to typecheck: bad contract type
-          { parameter nat ;
-            storage nat ;
-            code { DUP ;
-                   LAMBDA (pair nat nat) nat ADD ;
-                   SWAP ;
-                   EXEC ;
-                   NIL operation ;
-                   PAIR ;
-                   DIP { DROP } } }
+    ligo: error
+    generated Michelson contract failed to typecheck : bad contract type
+    code:
+     { parameter nat ;
+      storage nat ;
+      code { DUP ;
+             LAMBDA (pair nat nat) nat ADD ;
+             SWAP ;
+             EXEC ;
+             NIL operation ;
+             PAIR ;
+             DIP { DROP } } }
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -30,11 +32,13 @@ let%expect_test _ =
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; bad_contract "bad_michelson_insertion_2.ligo" ; "main" ] ;
   [%expect{|
-    ligo: in file "bad_michelson_insertion_2.ligo", line 5, characters 32-40. different kinds:  {"a":"nat","b":"( nat * nat )"}
+    ligo: error
+    in file "bad_michelson_insertion_2.ligo", line 3, character 0 to line 5, character 41
+    Constant declaration 'main'
+    Bad types: expected nat got ( nat * nat )
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
diff --git a/src/bin/expect_tests/contract_tests.ml b/src/bin/expect_tests/contract_tests.ml
index 3c5a794e6..b27434981 100644
--- a/src/bin/expect_tests/contract_tests.ml
+++ b/src/bin/expect_tests/contract_tests.ml
@@ -29,11 +29,17 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-storage" ; contract "coase.ligo" ; "main" ; "Buy_single (record card_to_buy = 1n end)" ] ;
   [%expect {|
-    ligo: different kinds:  {"a":"record[card_patterns -> (type_operator: Map (nat,record[coefficient -> mutez , quantity -> nat])) ,\n       cards -> (type_operator: Map (nat,record[card_owner -> address , card_pattern -> nat])) ,\n       next_id -> nat]","b":"sum[Buy_single -> record[card_to_buy -> nat] ,\n    Sell_single -> record[card_to_sell -> nat] ,\n    Transfer_single -> record[card_to_transfer -> nat ,\n                              destination -> address]]"}
+    ligo: error
+    Provided storage type does not match contract storage type
+    Bad types: expected record[card_patterns -> (type_operator: Map (nat,record[coefficient -> mutez , quantity -> nat])) ,
+                               cards -> (type_operator: Map (nat,record[card_owner -> address , card_pattern -> nat])) ,
+                               next_id -> nat] got sum[Buy_single -> record[card_to_buy -> nat] ,
+                                                       Sell_single -> record[card_to_sell -> nat] ,
+                                                       Transfer_single -> record[card_to_transfer -> nat ,
+                                                                        destination -> address]]
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -42,11 +48,17 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-parameter" ; contract "coase.ligo" ; "main" ; "record cards = (map end : cards) ; card_patterns = (map end : card_patterns) ; next_id = 3n ; end" ] ;
   [%expect {|
-    ligo: different kinds:  {"a":"sum[Buy_single -> record[card_to_buy -> nat] ,\n    Sell_single -> record[card_to_sell -> nat] ,\n    Transfer_single -> record[card_to_transfer -> nat ,\n                              destination -> address]]","b":"record[card_patterns -> (type_operator: Map (nat,record[coefficient -> mutez , quantity -> nat])) ,\n       cards -> (type_operator: Map (nat,record[card_owner -> address , card_pattern -> nat])) ,\n       next_id -> nat]"}
+    ligo: error
+    Provided parameter type does not match contract parameter type
+    Bad types: expected sum[Buy_single -> record[card_to_buy -> nat] ,
+                            Sell_single -> record[card_to_sell -> nat] ,
+                            Transfer_single -> record[card_to_transfer -> nat ,
+                                                      destination -> address]] got record[card_patterns -> (type_operator: Map (nat,record[coefficient -> mutez , quantity -> nat])) ,
+                                                                        cards -> (type_operator: Map (nat,record[card_owner -> address , card_pattern -> nat])) ,
+                                                                        next_id -> nat]
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1321,10 +1333,12 @@ let%expect_test _ =
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; contract "bad_type_operator.ligo" ; "main" ] ;
   [%expect {|
-    ligo: bad type operator (type_operator: Map (binding)):
+    ligo: error
+    in file "bad_type_operator.ligo", line 4, characters 16-29
+    unrecognized type operator (type_operator: Map (binding))
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1334,11 +1348,12 @@ let%expect_test _ =
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; contract "bad_address_format.religo" ; "main" ] ;
   [%expect {|
-    ligo: in file "bad_address_format.religo", line 2, characters 26-48. Badly formatted literal: @"KT1badaddr" {"location":"in file \"bad_address_format.religo\", line 2, characters 26-48"}
+    ligo: error
+    in file "bad_address_format.religo", line 2, characters 26-48
+    Badly formatted literal: @"KT1badaddr"
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1348,11 +1363,12 @@ let%expect_test _ =
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; contract "bad_timestamp.ligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "bad_timestamp.ligo", line 7, characters 30-44. Badly formatted timestamp "badtimestamp":  {"location":"in file \"bad_timestamp.ligo\", line 7, characters 30-44"}
+    ligo: error
+    in file "bad_timestamp.ligo", line 7, characters 30-44
+    Badly formatted timestamp 'badtimestamp'
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1385,10 +1401,11 @@ let%expect_test _ =
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; bad_contract "self_in_lambda.mligo" ; "main" ] ;
   [%expect {|
-    ligo: Wrong SELF_ADDRESS location: SELF_ADDRESS is only allowed at top-level
+    ligo: error
+    SELF_ADDRESS is only allowed at top-level
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1410,10 +1427,13 @@ let%expect_test _ =
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; bad_contract "long_sum_type_names.ligo" ; "main" ] ;
   [%expect {|
-    ligo: Too long constructor 'Incrementttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttt': names length is limited to 32 (tezos limitation)
+    ligo: error
+    in file "long_sum_type_names.ligo", line 2, character 2 to line 4, character 18
+    Too long constructor 'Incrementttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttttt'
+    names length are limited to 32 (tezos limitation)
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1428,11 +1448,15 @@ let%expect_test _ =
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; bad_contract "redundant_constructors.mligo" ; "main" ] ;
   [%expect {|
-    ligo: redundant constructor:  {"constructor":"Add","environment":"- E[]\tT[union_a -> sum[Add -> int , Remove -> int]\nbool -> sum[false -> unit , true -> unit]]"}
+    ligo: error
+    in file "redundant_constructors.mligo", line 7, character 2 to line 9, character 15
+    Redundant constructor:
+    Add
+    - Env:[]	Type env:[union_a -> sum[Add -> int , Remove -> int]
+    bool -> sum[false -> unit , true -> unit]]
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1442,11 +1466,14 @@ let%expect_test _ =
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; bad_contract "create_contract_toplevel.mligo" ; "main" ] ;
   [%expect {|
-ligo: in file "create_contract_toplevel.mligo", line 4, character 35 to line 8, character 8. No free variable allowed in this lambda: variable 'store' {"expression":"CREATE_CONTRACT(lambda (#P:Some(( nat * string ))) : None return\n                let rhs#2 = #P in\n                let p = rhs#2.0 in\n                let s = rhs#2.1 in\n                ( LIST_EMPTY() : (type_operator: list(operation)) , store ) ,\n                NONE() : (type_operator: option(key_hash)) ,\n                300000000mutez ,\n                \"un\")","location":"in file \"create_contract_toplevel.mligo\", line 4, character 35 to line 8, character 8"}
+ligo: error
+in file "create_contract_toplevel.mligo", line 3, characters 0-3
+Constant declaration 'main'
+in file "create_contract_toplevel.mligo", line 4, character 35 to line 8, character 8
+Free variable 'store' is not allowed in CREATE_CONTRACT lambda
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1455,11 +1482,14 @@ ligo: in file "create_contract_toplevel.mligo", line 4, character 35 to line 8,
 
   run_ligo_bad [ "compile-contract" ; bad_contract "create_contract_var.mligo" ; "main" ] ;
   [%expect {|
-ligo: in file "create_contract_var.mligo", line 6, character 35 to line 10, character 5. No free variable allowed in this lambda: variable 'a' {"expression":"CREATE_CONTRACT(lambda (#P:Some(( nat * int ))) : None return\n                let rhs#2 = #P in\n                let p = rhs#2.0 in\n                let s = rhs#2.1 in\n                ( LIST_EMPTY() : (type_operator: list(operation)) , a ) ,\n                NONE() : (type_operator: option(key_hash)) ,\n                300000000mutez ,\n                1)","location":"in file \"create_contract_var.mligo\", line 6, character 35 to line 10, character 5"}
+ligo: error
+in file "create_contract_var.mligo", line 5, characters 0-3
+Constant declaration 'main'
+in file "create_contract_var.mligo", line 6, character 35 to line 10, character 5
+Free variable 'a' is not allowed in CREATE_CONTRACT lambda
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1468,11 +1498,13 @@ ligo: in file "create_contract_var.mligo", line 6, character 35 to line 10, char
 
   run_ligo_bad [ "compile-contract" ; bad_contract "create_contract_no_inline.mligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "create_contract_no_inline.mligo", line 3, characters 40-46. unbound type variable:  {"variable":"return","location":"in file \"create_contract_no_inline.mligo\", line 3, characters 40-46","in":"- E[foo -> int]\tT[bool -> sum[false -> unit , true -> unit]]","did_you_mean":"no suggestion"}
+    ligo: error
+    in file "create_contract_no_inline.mligo", line 3, characters 40-46
+    Unbound type variable 'return'
+    - Env:[foo -> int]	Type env:[bool -> sum[false -> unit , true -> unit]]
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1522,11 +1554,14 @@ ligo: in file "create_contract_var.mligo", line 6, character 35 to line 10, char
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; bad_contract "self_type_annotation.ligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "self_type_annotation.ligo", line 8, characters 41-64. bad self type: expected (type_operator: Contract (int)) but got (type_operator: Contract (nat)) {"location":"in file \"self_type_annotation.ligo\", line 8, characters 41-64"}
+    ligo: error
+    in file "self_type_annotation.ligo", line 8, characters 41-64
+    Bad self type
+    expected (type_operator: Contract (int))
+    got (type_operator: Contract (nat))
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1549,11 +1584,13 @@ let%expect_test _ =
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; bad_contract "bad_contract.mligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "bad_contract.mligo", line 4, characters 0-3. badly typed contract: unexpected entrypoint type {"location":"in file \"bad_contract.mligo\", line 4, characters 0-3","entrypoint":"main","entrypoint_type":"( nat * int ) -> int"}
+    ligo: error
+    in file "bad_contract.mligo", line 4, characters 0-3
+    Badly typed contract:
+    unexpected entrypoint type ( nat * int ) -> int
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1562,11 +1599,13 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; bad_contract "bad_contract2.mligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "bad_contract2.mligo", line 5, characters 0-3. bad return type: expected (type_operator: list(operation)), got string {"location":"in file \"bad_contract2.mligo\", line 5, characters 0-3","entrypoint":"main"}
+    ligo: error
+    in file "bad_contract2.mligo", line 5, characters 0-3
+    Badly typed contract:
+    expected (type_operator: list(operation)) but got string
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1575,11 +1614,15 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; bad_contract "bad_contract3.mligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "bad_contract3.mligo", line 5, characters 0-3. badly typed contract: expected {int} and {string} to be the same in the entrypoint type {"location":"in file \"bad_contract3.mligo\", line 5, characters 0-3","entrypoint":"main","entrypoint_type":"( nat * int ) -> ( (type_operator: list(operation)) * string )"}
+    ligo: error
+    in file "bad_contract3.mligo", line 5, characters 0-3
+    Badly typed contract main:
+    expected storage type as right member of a pair in the input and output, but got:
+    - int in the input
+    - string in the output
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1631,11 +1674,13 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; bad_contract "self_bad_entrypoint_format.ligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "self_bad_entrypoint_format.ligo", line 8, characters 52-58. bad entrypoint format: entrypoint "Toto" is badly formatted. We expect "%bar" for entrypoint Bar and "%default" when no entrypoint used {"location":"in file \"self_bad_entrypoint_format.ligo\", line 8, characters 52-58"}
+    ligo: error
+    in file "self_bad_entrypoint_format.ligo", line 8, characters 52-58
+    Bad entrypoint format 'Toto'
+    We expect '%bar' for entrypoint Bar and '%default' when no entrypoint used
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1644,11 +1689,12 @@ let%expect_test _ =
 
   run_ligo_bad ["compile-contract"; bad_contract "nested_bigmap_1.religo"; "main"];
   [%expect {|
-    ligo: It looks like you have nested a big map inside another big map. This is not supported. :  {}
+    ligo: error
+    in file "nested_bigmap_1.religo", line 1, characters 11-29
+    It looks like you have nested a big map inside another big map, this is not supported
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1657,11 +1703,12 @@ let%expect_test _ =
 
   run_ligo_bad ["compile-contract"; bad_contract "nested_bigmap_2.religo"; "main"];
   [%expect {|
-    ligo: It looks like you have nested a big map inside another big map. This is not supported. :  {}
+    ligo: error
+    in file "nested_bigmap_2.religo", line 2, characters 29-50
+    It looks like you have nested a big map inside another big map, this is not supported
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1670,11 +1717,12 @@ let%expect_test _ =
   
   run_ligo_bad ["compile-contract"; bad_contract "nested_bigmap_3.religo"; "main"];
   [%expect {|
-    ligo: It looks like you have nested a big map inside another big map. This is not supported. :  {}
+    ligo: error
+    in file "nested_bigmap_3.religo", line 1, characters 11-29
+    It looks like you have nested a big map inside another big map, this is not supported
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -1683,11 +1731,12 @@ let%expect_test _ =
 
   run_ligo_bad ["compile-contract"; bad_contract "nested_bigmap_4.religo"; "main"];
   [%expect {|
-    ligo: It looks like you have nested a big map inside another big map. This is not supported. :  {}
+    ligo: error
+    in file "nested_bigmap_4.religo", line 2, characters 39-60
+    It looks like you have nested a big map inside another big map, this is not supported
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
diff --git a/src/bin/expect_tests/error_messages_tests.ml b/src/bin/expect_tests/error_messages_tests.ml
index 5f39e05b0..c5254d7da 100644
--- a/src/bin/expect_tests/error_messages_tests.ml
+++ b/src/bin/expect_tests/error_messages_tests.ml
@@ -3,18 +3,18 @@ open Cli_expect
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/gitlab_111.religo" ; "main" ] ;
   [%expect {|
-    ligo: : Parse error in file "gitlab_111.religo", line 2, characters 0-3 at "let", after "=":
-          This is an incorrect let binding. 
-          -
-          Examples of correct let bindings: 
-          let a: int = 4;
-          let (a: int, b: int) = (1, 2);
-          let func = (a: int, b: int) => a + b;
-           {}
+    ligo: error
+    Parse error in file "gitlab_111.religo", line 2, characters 0-3 at "let", after "=":
+    This is an incorrect let binding.
+    -
+    Examples of correct let bindings:
+    let a: int = 4;
+    let (a: int, b: int) = (1, 2);
+    let func = (a: int, b: int) => a + b;
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -23,13 +23,13 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/missing_rpar.religo" ; "main" ] ;
   [%expect {|
-    ligo: : Parse error in file "missing_rpar.religo", line 5, characters 0-3 at "let", after "m":
-          Missing `)`.
-           {}
+    ligo: error
+    Parse error in file "missing_rpar.religo", line 5, characters 0-3 at "let", after "m":
+    Missing `)`.
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
diff --git a/src/bin/expect_tests/failwith_tests.ml b/src/bin/expect_tests/failwith_tests.ml
index 8c5819ca4..8af9d0175 100644
--- a/src/bin/expect_tests/failwith_tests.ml
+++ b/src/bin/expect_tests/failwith_tests.ml
@@ -12,7 +12,7 @@ let%expect_test _ =
 
   run_ligo_good [ "run-function" ; contract "failwith.ligo" ; "failer" ; "1" ; "--format=json" ] ;
   [%expect {|
-    {"status":"ok","content":"failwith(42)"} |}];
+    {"value":null,"failure":"failwith(42)"} |}];
 
 
   run_ligo_good [ "dry-run" ; contract "subtle_nontail_fail.mligo" ; "main" ; "()" ; "()" ] ;
diff --git a/src/bin/expect_tests/lexer_tests.ml b/src/bin/expect_tests/lexer_tests.ml
index 20d26ab11..412fe48f3 100644
--- a/src/bin/expect_tests/lexer_tests.ml
+++ b/src/bin/expect_tests/lexer_tests.ml
@@ -3,14 +3,14 @@ open Cli_expect
 let%expect_test _ =
     run_ligo_bad [ "compile-contract" ; "../../test/lexer/broken_string.ligo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "broken_string.ligo", line 1, characters 18-19:
-      The string starting here is interrupted by a line break.
-      Hint: Remove the break, close the string before or insert a backslash.
-       {}
+ligo: error
+Lexical error in file "broken_string.ligo", line 1, characters 18-19:
+The string starting here is interrupted by a line break.
+Hint: Remove the break, close the string before or insert a backslash.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -20,14 +20,14 @@ ligo: : Lexical error in file "broken_string.ligo", line 1, characters 18-19:
 
     run_ligo_bad [ "compile-contract" ; "../../test/lexer/broken_string.mligo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "broken_string.mligo", line 1, characters 8-9:
-      The string starting here is interrupted by a line break.
-      Hint: Remove the break, close the string before or insert a backslash.
-       {}
+ligo: error
+Lexical error in file "broken_string.mligo", line 1, characters 8-9:
+The string starting here is interrupted by a line break.
+Hint: Remove the break, close the string before or insert a backslash.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -37,14 +37,14 @@ ligo: : Lexical error in file "broken_string.mligo", line 1, characters 8-9:
 
  run_ligo_bad [ "compile-contract" ; "../../test/lexer/broken_string.religo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "broken_string.religo", line 1, characters 8-9:
-      The string starting here is interrupted by a line break.
-      Hint: Remove the break, close the string before or insert a backslash.
-       {}
+ligo: error
+Lexical error in file "broken_string.religo", line 1, characters 8-9:
+The string starting here is interrupted by a line break.
+Hint: Remove the break, close the string before or insert a backslash.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -54,14 +54,14 @@ ligo: : Lexical error in file "broken_string.religo", line 1, characters 8-9:
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/negative_byte_sequence.ligo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "negative_byte_sequence.ligo", line 1, characters 18-31:
-      Negative byte sequence.
-      Hint: Remove the leading minus sign.
-       {}
+ligo: error
+Lexical error in file "negative_byte_sequence.ligo", line 1, characters 18-31:
+Negative byte sequence.
+Hint: Remove the leading minus sign.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -71,14 +71,14 @@ ligo: : Lexical error in file "negative_byte_sequence.ligo", line 1, characters
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/negative_byte_sequence.mligo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "negative_byte_sequence.mligo", line 1, characters 8-21:
-      Negative byte sequence.
-      Hint: Remove the leading minus sign.
-       {}
+ligo: error
+Lexical error in file "negative_byte_sequence.mligo", line 1, characters 8-21:
+Negative byte sequence.
+Hint: Remove the leading minus sign.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -88,14 +88,14 @@ ligo: : Lexical error in file "negative_byte_sequence.mligo", line 1, characters
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/negative_byte_sequence.religo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "negative_byte_sequence.religo", line 1, characters 8-21:
-      Negative byte sequence.
-      Hint: Remove the leading minus sign.
-       {}
+ligo: error
+Lexical error in file "negative_byte_sequence.religo", line 1, characters 8-21:
+Negative byte sequence.
+Hint: Remove the leading minus sign.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -124,14 +124,14 @@ ligo: : Lexical error in file "reserved_name.ligo", line 1, characters 4-13:
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/reserved_name.religo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "reserved_name.religo", line 1, characters 4-7:
-      Reserved name: "end".
-      Hint: Change the name.
-       {}
+ligo: error
+Lexical error in file "reserved_name.religo", line 1, characters 4-7:
+Reserved name: "end".
+Hint: Change the name.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -141,14 +141,14 @@ ligo: : Lexical error in file "reserved_name.religo", line 1, characters 4-7:
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/reserved_name.mligo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "reserved_name.mligo", line 1, characters 4-10:
-      Reserved name: "object".
-      Hint: Change the name.
-       {}
+ligo: error
+Lexical error in file "reserved_name.mligo", line 1, characters 4-10:
+Reserved name: "object".
+Hint: Change the name.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -158,13 +158,13 @@ ligo: : Lexical error in file "reserved_name.mligo", line 1, characters 4-10:
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/unexpected_character.ligo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "unexpected_character.ligo", line 1, characters 18-19:
-      Unexpected character '\239'.
-       {}
+ligo: error
+Lexical error in file "unexpected_character.ligo", line 1, characters 18-19:
+Unexpected character '\239'.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -174,13 +174,13 @@ ligo: : Lexical error in file "unexpected_character.ligo", line 1, characters 18
 
  run_ligo_bad [ "compile-contract" ; "../../test/lexer/unexpected_character.mligo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "unexpected_character.mligo", line 1, characters 8-9:
-      Unexpected character '\239'.
-       {}
+ligo: error
+Lexical error in file "unexpected_character.mligo", line 1, characters 8-9:
+Unexpected character '\239'.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -190,13 +190,13 @@ ligo: : Lexical error in file "unexpected_character.mligo", line 1, characters 8
 
  run_ligo_bad [ "compile-contract" ; "../../test/lexer/unexpected_character.religo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "unexpected_character.religo", line 1, characters 8-9:
-      Unexpected character '\239'.
-       {}
+ligo: error
+Lexical error in file "unexpected_character.religo", line 1, characters 8-9:
+Unexpected character '\239'.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -206,13 +206,13 @@ ligo: : Lexical error in file "unexpected_character.religo", line 1, characters
 
  run_ligo_bad [ "compile-contract" ; "../../test/lexer/unterminated_comment.mligo" ; "main" ] ;
   [%expect {|
-ligo: : Preprocessing error in file "../../test/lexer/unterminated_comment.mligo", line 1, characters 0-2:
-      Unterminated comment.
-      Hint: Close with "*)". {}
+ligo: error
+Preprocessing error in file "../../test/lexer/unterminated_comment.mligo", line 1, characters 0-2:
+Unterminated comment.
+Hint: Close with "*)".
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -222,14 +222,14 @@ ligo: : Preprocessing error in file "../../test/lexer/unterminated_comment.mligo
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/invalid_symbol.ligo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "invalid_symbol.ligo", line 1, characters 17-20:
-      Invalid symbol.
-      Hint: Check the LIGO syntax you use.
-       {}
+ligo: error
+Lexical error in file "invalid_symbol.ligo", line 1, characters 17-20:
+Invalid symbol.
+Hint: Check the LIGO syntax you use.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -239,14 +239,14 @@ ligo: : Lexical error in file "invalid_symbol.ligo", line 1, characters 17-20:
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/invalid_symbol.mligo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "invalid_symbol.mligo", line 1, characters 10-13:
-      Invalid symbol.
-      Hint: Check the LIGO syntax you use.
-       {}
+ligo: error
+Lexical error in file "invalid_symbol.mligo", line 1, characters 10-13:
+Invalid symbol.
+Hint: Check the LIGO syntax you use.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -256,14 +256,14 @@ ligo: : Lexical error in file "invalid_symbol.mligo", line 1, characters 10-13:
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/invalid_symbol.religo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "invalid_symbol.religo", line 1, characters 10-11:
-      Invalid symbol.
-      Hint: Check the LIGO syntax you use.
-       {}
+ligo: error
+Lexical error in file "invalid_symbol.religo", line 1, characters 10-11:
+Invalid symbol.
+Hint: Check the LIGO syntax you use.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -273,14 +273,14 @@ ligo: : Lexical error in file "invalid_symbol.religo", line 1, characters 10-11:
 
  run_ligo_bad [ "compile-contract" ; "../../test/lexer/missing_break.ligo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "missing_break.ligo", line 1, characters 18-18:
-      Missing break.
-      Hint: Insert some space.
-       {}
+ligo: error
+Lexical error in file "missing_break.ligo", line 1, characters 18-18:
+Missing break.
+Hint: Insert some space.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -290,14 +290,14 @@ ligo: : Lexical error in file "missing_break.ligo", line 1, characters 18-18:
 
  run_ligo_bad [ "compile-contract" ; "../../test/lexer/missing_break.mligo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "missing_break.mligo", line 1, characters 11-11:
-      Missing break.
-      Hint: Insert some space.
-       {}
+ligo: error
+Lexical error in file "missing_break.mligo", line 1, characters 11-11:
+Missing break.
+Hint: Insert some space.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -307,14 +307,14 @@ ligo: : Lexical error in file "missing_break.mligo", line 1, characters 11-11:
 
  run_ligo_bad [ "compile-contract" ; "../../test/lexer/missing_break.religo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "missing_break.religo", line 1, characters 11-11:
-      Missing break.
-      Hint: Insert some space.
-       {}
+ligo: error
+Lexical error in file "missing_break.religo", line 1, characters 11-11:
+Missing break.
+Hint: Insert some space.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -324,14 +324,14 @@ ligo: : Lexical error in file "missing_break.religo", line 1, characters 11-11:
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/invalid_character_in_string.ligo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "invalid_character_in_string.ligo", line 1, characters 19-20:
-      Invalid character in string.
-      Hint: Remove or replace the character.
-       {}
+ligo: error
+Lexical error in file "invalid_character_in_string.ligo", line 1, characters 19-20:
+Invalid character in string.
+Hint: Remove or replace the character.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -341,14 +341,14 @@ ligo: : Lexical error in file "invalid_character_in_string.ligo", line 1, charac
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/invalid_character_in_string.mligo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "invalid_character_in_string.mligo", line 1, characters 9-10:
-      Invalid character in string.
-      Hint: Remove or replace the character.
-       {}
+ligo: error
+Lexical error in file "invalid_character_in_string.mligo", line 1, characters 9-10:
+Invalid character in string.
+Hint: Remove or replace the character.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -358,14 +358,14 @@ ligo: : Lexical error in file "invalid_character_in_string.mligo", line 1, chara
 
 run_ligo_bad [ "compile-contract" ; "../../test/lexer/invalid_character_in_string.religo" ; "main" ] ;
   [%expect {|
-ligo: : Lexical error in file "invalid_character_in_string.religo", line 1, characters 9-10:
-      Invalid character in string.
-      Hint: Remove or replace the character.
-       {}
+ligo: error
+Lexical error in file "invalid_character_in_string.religo", line 1, characters 9-10:
+Invalid character in string.
+Hint: Remove or replace the character.
 
 
- If you're not sure how to fix this error, you can
- do one of the following:
+
+If you're not sure how to fix this error, you can do one of the following:
 
 * Visit our documentation: https://ligolang.org/docs/intro/introduction
 * Ask a question on our Discord: https://discord.gg/9rhYaEt
diff --git a/src/bin/expect_tests/literals.ml b/src/bin/expect_tests/literals.ml
index aebe463e3..e265b2437 100644
--- a/src/bin/expect_tests/literals.ml
+++ b/src/bin/expect_tests/literals.ml
@@ -7,11 +7,12 @@ let%expect_test _ =
 let%expect_test _ =
   run_ligo_bad ["interpret" ; "(\"thisisnotasignature\":signature)" ; "--syntax=pascaligo"] ;
   [%expect {|
-    ligo: in file "", line 0, characters 0-33. Badly formatted literal: Signature thisisnotasignature {"location":"in file \"\", line 0, characters 0-33"}
+    ligo: error
+    in file "", line 0, characters 0-33
+    Badly formatted literal: Signature thisisnotasignature
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -25,11 +26,12 @@ let%expect_test _ =
 let%expect_test _ =
   run_ligo_bad ["interpret" ; "(\"thisisnotapublickey\":key)" ; "--syntax=pascaligo"] ;
   [%expect {|
-    ligo: in file "", line 0, characters 0-27. Badly formatted literal: key thisisnotapublickey {"location":"in file \"\", line 0, characters 0-27"}
+    ligo: error
+    in file "", line 0, characters 0-27
+    Badly formatted literal: key thisisnotapublickey
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
diff --git a/src/bin/expect_tests/michelson_converter.ml b/src/bin/expect_tests/michelson_converter.ml
index b8a6cd90e..b3a2a18c0 100644
--- a/src/bin/expect_tests/michelson_converter.ml
+++ b/src/bin/expect_tests/michelson_converter.ml
@@ -8,10 +8,13 @@ let bad_contract basename =
 let%expect_test _ =
   run_ligo_bad [ "interpret" ; "--init-file="^(bad_contract "michelson_converter_no_annotation.mligo") ; "l4"] ;
   [%expect {|
-    ligo: in file "michelson_converter_no_annotation.mligo", line 4, characters 9-39. can't retrieve type declaration order in the converted record, you need to annotate it
+    ligo: error
+    in file "michelson_converter_no_annotation.mligo", line 4, characters 9-39
+    Constant declaration 'l4'
+    Can't retrieve type declaration order in the converted record, you need to annotate it
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -20,10 +23,14 @@ let%expect_test _ =
 
   run_ligo_bad [ "interpret" ; "--init-file="^(bad_contract "michelson_converter_short_record.mligo") ; "l1"] ;
   [%expect {|
-    ligo: in file "michelson_converter_short_record.mligo", line 4, characters 9-44. converted record must have at least two elements
+    ligo: error
+    in file "michelson_converter_short_record.mligo", line 4, characters 9-44
+    Constant declaration 'l1'
+    in file "michelson_converter_short_record.mligo", line 1, characters 10-23
+    Converted record must have at least two elements
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
diff --git a/src/bin/expect_tests/michelson_or_tests.ml b/src/bin/expect_tests/michelson_or_tests.ml
index 66c49dcc0..92b7c9554 100644
--- a/src/bin/expect_tests/michelson_or_tests.ml
+++ b/src/bin/expect_tests/michelson_or_tests.ml
@@ -29,11 +29,14 @@ let%expect_test _ =
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; bad_contract "bad_michelson_or.mligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "bad_michelson_or.mligo", line 6, characters 12-27. michelson_or types must be annotated:  {"constructor":"M_right","location":"in file \"bad_michelson_or.mligo\", line 6, characters 12-27"}
+    ligo: error
+    in file "bad_michelson_or.mligo", line 5, characters 0-3
+    Constant declaration 'main'
+    in file "bad_michelson_or.mligo", line 6, characters 12-27
+    michelson_or contructor M_right must be annotated with a sum type
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
diff --git a/src/bin/expect_tests/misc_cli_commands.ml b/src/bin/expect_tests/misc_cli_commands.ml
index ee67b18e0..2cbae54b0 100644
--- a/src/bin/expect_tests/misc_cli_commands.ml
+++ b/src/bin/expect_tests/misc_cli_commands.ml
@@ -13,10 +13,46 @@ let%expect_test _ =
 (* list-declarations *)
 let%expect_test _ =
   run_ligo_good [ "list-declarations" ; "../../test/contracts/loop.ligo" ] ;
-  [%expect {| {"source_file":"../../test/contracts/loop.ligo","declarations":["inner_capture_in_conditional_block","dummy","nested_for_collection_local_var","nested_for_collection","for_collection_map_k","for_collection_map_kv","for_collection_empty","for_collection_with_patches","for_collection_comp_with_acc","for_collection_proc_call","for_collection_rhs_capture","for_collection_if_and_local_var","for_collection_set","for_collection_list","for_sum_step","for_sum","while_sum","counter"]} |} ];
+  [%expect {|
+    ../../test/contracts/loop.ligo declarations:
+    inner_capture_in_conditional_block
+    dummy
+    nested_for_collection_local_var
+    nested_for_collection
+    for_collection_map_k
+    for_collection_map_kv
+    for_collection_empty
+    for_collection_with_patches
+    for_collection_comp_with_acc
+    for_collection_proc_call
+    for_collection_rhs_capture
+    for_collection_if_and_local_var
+    for_collection_set
+    for_collection_list
+    for_sum_step
+    for_sum
+    while_sum
+    counter |} ];
+
+  run_ligo_good [ "list-declarations" ; "../../test/contracts/loop.mligo" ; "--format=json" ] ;
+  [%expect {|
+    {"source_file":"../../test/contracts/loop.mligo","declarations":["counter_nest","aux_nest","counter","counter_simple","aux_simple"]} |} ];
+
 
   run_ligo_good [ "list-declarations" ; "../../test/contracts/loop.mligo" ] ;
-  [%expect {| {"source_file":"../../test/contracts/loop.mligo","declarations":["counter_nest","aux_nest","counter","counter_simple","aux_simple"]} |} ];
+  [%expect {|
+    ../../test/contracts/loop.mligo declarations:
+    counter_nest
+    aux_nest
+    counter
+    counter_simple
+    aux_simple |} ];
 
   run_ligo_good [ "list-declarations" ; "../../test/contracts/loop.religo" ] ;
-  [%expect {| {"source_file":"../../test/contracts/loop.religo","declarations":["counter_nest","aux_nest","counter","counter_simple","aux_simple"]} |} ];
+  [%expect {|
+    ../../test/contracts/loop.religo declarations:
+    counter_nest
+    aux_nest
+    counter
+    counter_simple
+    aux_simple |} ];
diff --git a/src/bin/expect_tests/syntax_error_tests.ml b/src/bin/expect_tests/syntax_error_tests.ml
index 0968c1d5b..7b1bcb09d 100644
--- a/src/bin/expect_tests/syntax_error_tests.ml
+++ b/src/bin/expect_tests/syntax_error_tests.ml
@@ -3,12 +3,12 @@ open Cli_expect
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_syntax.ligo" ; "main" ] ;
   [%expect {|
-    ligo: : Parse error in file "error_syntax.ligo", line 1, characters 16-17 at "-", after "bar":
-          16: <syntax error> {}
+    ligo: error
+    Parse error in file "error_syntax.ligo", line 1, characters 16-17 at "-", after "bar":
+    16: <syntax error>
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -17,17 +17,18 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_function_arguments.religo" ; "main" ] ;
   [%expect {|
-    ligo: in file "error_function_arguments.religo", line 1, characters 14-27. : It looks like you are defining a function, however we do not
-          understand the parameters declaration.
-          Examples of valid functions:
-          let x = (a: string, b: int) : int => 3;
-          let tuple = ((a, b): (int, int)) => a + b; 
-          let x = (a: string) : string => "Hello, " ++ a;
-           {"location":"in file \"error_function_arguments.religo\", line 1, characters 14-27"}
-      
+    ligo: error
+    in file "error_function_arguments.religo", line 1, characters 14-27
+    It looks like you are defining a function, however we do not
+    understand the parameters declaration.
+    Examples of valid functions:
+    let x = (a: string, b: int) : int => 3;
+    let tuple = ((a, b): (int, int)) => a + b;
+    let x = (a: string) : string => "Hello, " ++ a;
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+
+
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
diff --git a/src/bin/expect_tests/typer_error_tests.ml b/src/bin/expect_tests/typer_error_tests.ml
index c8690a3e5..182b54235 100644
--- a/src/bin/expect_tests/typer_error_tests.ml
+++ b/src/bin/expect_tests/typer_error_tests.ml
@@ -3,11 +3,13 @@ open Cli_expect
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_function_annotation_1.mligo"; "main"];
   [%expect {|
-    ligo: in file "error_function_annotation_1.mligo", line 1, characters 0-3. different type constructors: Expected these two constant type constructors to be the same, but they're different {"a":"unit","b":"int"}
+    ligo: error
+    in file "error_function_annotation_1.mligo", line 1, characters 0-3
+    Constant declaration 'main'
+    Bad types: expected int -> unit got int -> int
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -16,11 +18,13 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_function_annotation_2.mligo"; "f"];
   [%expect {|
-    ligo: in file "error_function_annotation_2.mligo", line 1, characters 14-43. different kinds:  {"a":"int","b":"( int * int ) -> int"}
+    ligo: error
+    in file "error_function_annotation_2.mligo", line 1, characters 14-43
+    Constant declaration 'f'
+    Bad types: expected int got ( int * int ) -> int
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -29,11 +33,18 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_function_annotation_3.mligo"; "f"];
   [%expect {|
-    ligo: in file "error_function_annotation_3.mligo", line 6, characters 0-3. different kinds:  {"a":"( (type_operator: list(operation)) * sum[Add -> int , Sub -> int] )","b":"sum[Add -> int , Sub -> int]"}
+    ligo: error
+    in file "error_function_annotation_3.mligo", line 6, characters 0-3
+    Constant declaration 'main'
+    Bad types: expected ( int * sum[Add -> int , Sub -> int] ) -> ( (type_operator: list(operation)) *
+                                                                    sum[Add -> int ,
+                                                                        Sub -> int] ) got ( int *
+                                                                        sum[Add -> int ,
+                                                                        Sub -> int] ) -> sum[Add -> int ,
+                                                                        Sub -> int]
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -42,11 +53,12 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_no_tail_recursive_function.mligo"; "f"];
   [%expect {|
-    ligo: in file "error_no_tail_recursive_function.mligo", line 2, characters 14-21. Recursion must be achieved through tail-calls only:  {"function":"unvalid","location":"in file \"error_no_tail_recursive_function.mligo\", line 2, characters 14-21"}
+    ligo: error
+    in file "error_no_tail_recursive_function.mligo", line 2, characters 14-21
+    Recursion must be achieved through tail-calls only
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -55,10 +67,15 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_type.ligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "error_type.ligo", line 3, characters 18-28. Adding modulo with wrong types: Expected arguments with one of the following combinations of types: add(nat , nat) or add(int , int) or add(mutez , mutez) or add(nat , int) or add(int , nat) or add(timestamp , int) or add(int , timestamp) but got this combination instead: add(int , string)
+    ligo: error
+    in file "error_type.ligo", line 3, characters 18-28
+    Constant declaration 'foo'
+    Expected arguments with one of the following combinations of type:
+    (nat , nat) or (int , int) or (mutez , mutez) or (nat , int) or (int , nat) or (timestamp , int) or (int , timestamp)
+    but got int , string
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -67,11 +84,13 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_typer_1.mligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "error_typer_1.mligo", line 3, characters 19-27. different type constructors: Expected these two constant type constructors to be the same, but they're different {"a":"string","b":"int"}
+    ligo: error
+    in file "error_typer_1.mligo", line 3, characters 19-27
+    Constant declaration 'foo'
+    Bad types: expected string got int
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -80,11 +99,13 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_typer_2.mligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "error_typer_2.mligo", line 3, characters 24-39. different type constructors: Expected these two n-ary type constructors to be the same, but they're different {"a":"(type_operator: list(string))","b":"(type_operator: option(int))"}
+    ligo: error
+    in file "error_typer_2.mligo", line 3, characters 24-39
+    Constant declaration 'foo'
+    Bad types: expected (type_operator: list(string)) got (type_operator: option(int))
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -93,11 +114,14 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_typer_3.mligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "error_typer_3.mligo", line 3, characters 34-53. tuples have different sizes: Expected these two types to be the same, but they're different (both are tuples, but with a different number of arguments) {"a":"( int * string * sum[false -> unit , true -> unit] )","b":"( int * string )"}
+    ligo: error
+    in file "error_typer_3.mligo", line 3, characters 34-53
+    Constant declaration 'foo'
+    Bad types: expected ( int * string * sum[false -> unit , true -> unit] ) got ( int *
+                                                                        string )
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -106,11 +130,18 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_typer_4.mligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "error_typer_4.mligo", line 4, characters 17-56. different keys in records:  {"key_a":"c","key_b":"b","a":"record[a -> int , c -> sum[false -> unit , true -> unit] , d -> string]","b":"record[a -> int , b -> string , c -> sum[false -> unit , true -> unit]]"}
+    ligo: error
+    in file "error_typer_4.mligo", line 4, characters 17-56
+    Constant declaration 'foo'
+    Bad types: expected record[a -> int ,
+                               c -> sum[false -> unit , true -> unit] ,
+                               d -> string] got record[a -> int ,
+                                                       b -> string ,
+                                                       c -> sum[false -> unit ,
+                                                                true -> unit]]
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -119,11 +150,13 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_typer_5.mligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "error_typer_5.mligo", line 1, characters 10-17. unbound type variable:  {"variable":"boolean","location":"in file \"error_typer_5.mligo\", line 1, characters 10-17","in":"- E[]\tT[bool -> sum[false -> unit , true -> unit]]","did_you_mean":"bool"}
+    ligo: error
+    in file "error_typer_5.mligo", line 1, characters 10-17
+    Unbound type variable 'boolean'
+    - Env:[]	Type env:[bool -> sum[false -> unit , true -> unit]]
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -132,11 +165,13 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_typer_6.mligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "error_typer_6.mligo", line 1, characters 30-64. different kinds:  {"a":"string","b":"sum[false -> unit , true -> unit]"}
+    ligo: error
+    in file "error_typer_6.mligo", line 1, characters 30-64
+    Constant declaration 'foo'
+    Bad types: expected (type_operator: Map (int,string)) got (type_operator: Map (int,sum[false -> unit , true -> unit]))
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -145,11 +180,16 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_typer_7.mligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "error_typer_7.mligo", line 4, characters 18-48. records have different sizes: Expected these two types to be the same, but they're different (both are records, but with a different number of arguments) {"a":"record[a -> int , b -> string]","b":"record[a -> int , b -> string , c -> sum[false -> unit , true -> unit]]"}
+    ligo: error
+    in file "error_typer_7.mligo", line 4, characters 17-56
+    Constant declaration 'foo'
+    Bad types: expected record[a -> int , b -> string] got record[a -> int ,
+                                                                  b -> string ,
+                                                                  c -> sum[false -> unit ,
+                                                                        true -> unit]]
 
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -158,12 +198,16 @@ let%expect_test _ =
 
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/id.mligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "id.mligo", line 45, characters 4-51. Expected a different type: Expected the type option but got the type record[controller -> address ,
-                                                           owner -> address ,
-                                                           profile -> bytes]
+    ligo: error
+    in file "id.mligo", line 28, characters 0-3
+    Constant declaration 'buy'
+    in file "id.mligo", line 3, character 18 to line 7, character 1
+    Expected an option but got record[controller -> address ,
+                                      owner -> address ,
+                                      profile -> bytes]
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -181,10 +225,11 @@ let%expect_test _ =
 
   run_ligo_bad [ "interpret" ; "Set.literal [ (1,2,3) ; (2,3,4) ]" ; "--syntax=cameligo" ] ;
   [%expect {|
-    ligo: not a comparable type: pair (use (a,(b,c)) instead of (a,b,c))
+    ligo: error
+    pair does not have a comparable structure. (hint: use (a,(b,c)) instead of (a,b,c))
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
@@ -194,10 +239,15 @@ let%expect_test _ =
 let%expect_test _ =
   run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/failwith_wrong_type.ligo" ; "main" ] ;
   [%expect {|
-    ligo: in file "failwith_wrong_type.ligo", line 2, characters 19-46. Failwith with disallowed type: Expected arguments with one of the following combinations of types: failwith(string) or failwith(nat) or failwith(int) but got this combination instead: failwith((type_operator: list(int)))
+    ligo: error
+    in file "failwith_wrong_type.ligo", line 2, characters 19-46
+    Constant declaration 'bad'
+    Expected arguments with one of the following combinations of type:
+    (string) or (nat) or (int)
+    but got (type_operator: list(int))
 
-     If you're not sure how to fix this error, you can
-     do one of the following:
+
+    If you're not sure how to fix this error, you can do one of the following:
 
     * Visit our documentation: https://ligolang.org/docs/intro/introduction
     * Ask a question on our Discord: https://discord.gg/9rhYaEt
diff --git a/src/passes/01-parser/formatter.ml b/src/passes/01-parser/formatter.ml
index 14a16b7aa..9d43eb119 100644
--- a/src/passes/01-parser/formatter.ml
+++ b/src/passes/01-parser/formatter.ml
@@ -2,7 +2,7 @@ open Display
 
 let ppx_ppformat ~display_format f (buf,_) =
   match display_format with
-  | Human_readable | Dev -> Format.fprintf f "%s\n" (Buffer.contents buf)
+  | Human_readable | Dev -> Format.fprintf f "%s" (Buffer.contents buf)
 
 let ppx_jsonformat (buf,_) : json =
   let s = Format.asprintf "%s" (Buffer.contents buf) in