Instant unification error on arguments count mismatch (#225)

* Instant unification error on arguments count mismatch

* add testcase

* Add newline

src/aeso_ast_infer_types.erl

@@ -2072,7 +2072,8 @@ unify1(_Env, {qcon, _, Name}, {qcon, _, Name}, _When) ->
     true;
 unify1(_Env, {bytes_t, _, Len}, {bytes_t, _, Len}, _When) ->
     true;
-unify1(Env, {fun_t, _, Named1, Args1, Result1}, {fun_t, _, Named2, Args2, Result2}, When) ->
+unify1(Env, {fun_t, _, Named1, Args1, Result1}, {fun_t, _, Named2, Args2, Result2}, When)
+    when length(Args1) == length(Args2) ->
     unify(Env, Named1, Named2, When) andalso
     unify(Env, Args1, Args2, When) andalso unify(Env, Result1, Result2, When);
 unify1(Env, {app_t, _, {Tag, _, F}, Args1}, {app_t, _, {Tag, _, F}, Args2}, When)

test/aeso_compiler_tests.erl

@@ -623,6 +623,28 @@ failing_contracts() ->
            "Empty record/map update\n"
            "  r {}">>
         ])
+    , ?TYPE_ERROR(bad_number_of_args,
+                  [<<?Pos(3, 39)
+                     "Cannot unify () => unit\n"
+                     "         and (int) => 'a\n",
+                     "when checking the application at line 3, column 39 of\n"
+                     "  f : () => unit\n"
+                     "to arguments\n"
+                     "  1 : int">>,
+                   <<?Pos(4, 20)
+                     "Cannot unify (int, string) => 'e\n"
+                     "         and (int) => 'd\n"
+                     "when checking the application at line 4, column 20 of\n"
+                     "  g : (int, string) => 'e\n"
+                     "to arguments\n"
+                     "  1 : int">>,
+                   <<?Pos(5, 20)
+                     "Cannot unify (int, string) => 'c\n"
+                     "         and (string) => 'b\n"
+                     "when checking the application at line 5, column 20 of\n"
+                     "  g : (int, string) => 'c\nto arguments\n"
+                     "  \"Litwo, ojczyzno moja\" : string">>
+                  ])
     ].
 
 -define(Path(File), "code_errors/" ??File).

test/contracts/bad_number_of_args.aes

@@ -0,0 +1,6 @@
+contract Test =
+  entrypoint f() = ()
+  entrypoint g(x : int, y : string) = f(1)
+  entrypoint h() = g(1)
+  entrypoint i() = g("Litwo, ojczyzno moja")
+