fix: do not error when using algopy.arc4.abi_call with a method sel…

…ector string containing no arguments

examples/sizes.txt

@@ -111,8 +111,8 @@
   tuple_support/NestedTuples                       956       613    343       613      0 
   tuple_support/TupleComparisons                   136        68     68        68      0 
   tuple_support/TupleSupport                       696       409    287       409      0 
-  typed_abi_call/Greeter                          2852      2437    415      2437      0 
-  typed_abi_call/Logger                            882       748    134       748      0 
+  typed_abi_call/Greeter                          3007      2588    419      2588      0 
+  typed_abi_call/Logger                            914       778    136       778      0 
   unary/Unary                                      130        67     63        67      0 
   unassigned_expression/Unassigned                 132       107     25       107      0 
   undefined_phi_args/Baddie                        324       284     40       284      0 

src/puya/awst_build/eb/arc4/_utils.py

@@ -161,7 +161,7 @@ def _split_signature(
         if remaining:
             if not name:
                 name = remaining
-            elif not args:
+            elif args is None:
                 raise CodeError(
                     f"invalid signature, args not well defined: {name=}, {remaining=}", location
                 )

test_cases/typed_abi_call/logger.py

@@ -22,6 +22,10 @@ class Logger(ARC4Contract):
     def echo(self, value: arc4.String) -> arc4.String:
         return "echo: " + value
 
+    @arc4.abimethod
+    def no_args(self) -> UInt64:
+        return UInt64(42)
+
     @arc4.abimethod(name=LOG_METHOD_NAME)
     def log_uint64(self, value: arc4.UInt64) -> None:
         log(value)

test_cases/typed_abi_call/out/Greeter.approval.teal

@@ -4,7 +4,7 @@ test_cases.typed_abi_call.typed_c2c.Greeter.approval_program:
     // typed_abi_call/typed_c2c.py:17
     // class Greeter(ARC4Contract):
     txn NumAppArgs
-    bz main_bare_routing@15
+    bz main_bare_routing@16
     method "test_method_selector_kinds(application)void"
     method "test_method_overload(application)void"
     method "test_arg_conversion(application)void"
@@ -16,8 +16,9 @@ test_cases.typed_abi_call.typed_c2c.Greeter.approval_program:
     method "test_native_uint64(application)void"
     method "test_native_biguint(application)void"
     method "test_native_tuple(application)void"
+    method "test_no_args(application)void"
     txna ApplicationArgs 0
-    match main_test_method_selector_kinds_route@2 main_test_method_overload_route@3 main_test_arg_conversion_route@4 main_test_15plus_args_route@5 main_test_void_route@6 main_test_ref_types_route@7 main_test_native_string_route@8 main_test_native_bytes_route@9 main_test_native_uint64_route@10 main_test_native_biguint_route@11 main_test_native_tuple_route@12
+    match main_test_method_selector_kinds_route@2 main_test_method_overload_route@3 main_test_arg_conversion_route@4 main_test_15plus_args_route@5 main_test_void_route@6 main_test_ref_types_route@7 main_test_native_string_route@8 main_test_native_bytes_route@9 main_test_native_uint64_route@10 main_test_native_biguint_route@11 main_test_native_tuple_route@12 main_test_no_args_route@13
     err // reject transaction
 
 main_test_method_selector_kinds_route@2:
@@ -232,7 +233,26 @@ main_test_native_tuple_route@12:
     int 1
     return
 
-main_bare_routing@15:
+main_test_no_args_route@13:
+    // typed_abi_call/typed_c2c.py:215
+    // @arc4.abimethod()
+    txn OnCompletion
+    !
+    assert // OnCompletion is NoOp
+    txn ApplicationID
+    assert // is not creating
+    // typed_abi_call/typed_c2c.py:17
+    // class Greeter(ARC4Contract):
+    txna ApplicationArgs 1
+    btoi
+    txnas Applications
+    // typed_abi_call/typed_c2c.py:215
+    // @arc4.abimethod()
+    callsub test_no_args
+    int 1
+    return
+
+main_bare_routing@16:
     // typed_abi_call/typed_c2c.py:17
     // class Greeter(ARC4Contract):
     txn OnCompletion
@@ -1589,3 +1609,93 @@ test_native_tuple:
     ==
     assert
     retsub
+
+
+// test_cases.typed_abi_call.typed_c2c.Greeter.test_no_args(app: uint64) -> void:
+test_no_args:
+    // typed_abi_call/typed_c2c.py:215-216
+    // @arc4.abimethod()
+    // def test_no_args(self, app: Application) -> None:
+    proto 1 0
+    // typed_abi_call/typed_c2c.py:217
+    // result, _txn = arc4.abi_call(Logger.no_args, app_id=app)
+    itxn_begin
+    frame_dig -1
+    itxn_field ApplicationID
+    method "no_args()uint64"
+    itxn_field ApplicationArgs
+    int appl
+    itxn_field TypeEnum
+    int 0
+    itxn_field Fee
+    itxn_submit
+    itxn LastLog
+    dup
+    extract 4 0
+    swap
+    extract 0 4
+    byte 0x151f7c75
+    ==
+    assert // ARC4 prefix is valid
+    btoi
+    // typed_abi_call/typed_c2c.py:218
+    // assert result == 42
+    int 42
+    ==
+    assert
+    // typed_abi_call/typed_c2c.py:219
+    // arc4_result, _txn = arc4.abi_call[arc4.UInt64]("no_args()uint64", app_id=app)
+    itxn_begin
+    frame_dig -1
+    itxn_field ApplicationID
+    method "no_args()uint64"
+    itxn_field ApplicationArgs
+    int appl
+    itxn_field TypeEnum
+    int 0
+    itxn_field Fee
+    itxn_submit
+    itxn LastLog
+    dup
+    extract 4 0
+    swap
+    extract 0 4
+    byte 0x151f7c75
+    ==
+    assert // ARC4 prefix is valid
+    // typed_abi_call/typed_c2c.py:220
+    // assert arc4_result == 42
+    byte 0x000000000000002a
+    b==
+    assert
+    // typed_abi_call/typed_c2c.py:222
+    // arc4.abi_call(Logger.no_args, app_id=app)
+    itxn_begin
+    frame_dig -1
+    itxn_field ApplicationID
+    method "no_args()uint64"
+    itxn_field ApplicationArgs
+    int appl
+    itxn_field TypeEnum
+    int 0
+    itxn_field Fee
+    itxn_submit
+    itxn LastLog
+    extract 0 4
+    byte 0x151f7c75
+    ==
+    assert // ARC4 prefix is valid
+    // typed_abi_call/typed_c2c.py:223
+    // assert arc4.UInt64.from_log(op.ITxn.last_log()) == 42
+    itxn LastLog
+    dup
+    extract 4 0
+    swap
+    extract 0 4
+    byte 0x151f7c75
+    ==
+    assert // ARC4 prefix is valid
+    byte 0x000000000000002a
+    b==
+    assert
+    retsub

test_cases/typed_abi_call/out/Greeter.destructured.ir

@@ -3,10 +3,10 @@ contract test_cases.typed_abi_call.typed_c2c.Greeter:
         subroutine test_cases.typed_abi_call.typed_c2c.Greeter.approval_program() -> bool:
             block@0: // L17
                 let tmp%0#0: bool = (txn NumAppArgs)
-                goto tmp%0#0 ? block@1 : block@15
+                goto tmp%0#0 ? block@1 : block@16
             block@1: // abi_routing_L17
                 let tmp%1#0: bytes = (txna ApplicationArgs 0)
-                switch tmp%1#0 {method "test_method_selector_kinds(application)void" => block@2, method "test_method_overload(application)void" => block@3, method "test_arg_conversion(application)void" => block@4, method "test_15plus_args(application)void" => block@5, method "test_void(application)void" => block@6, method "test_ref_types(application,asset)void" => block@7, method "test_native_string(application)void" => block@8, method "test_native_bytes(application)void" => block@9, method "test_native_uint64(application)void" => block@10, method "test_native_biguint(application)void" => block@11, method "test_native_tuple(application)void" => block@12, * => fail // reject transaction}
+                switch tmp%1#0 {method "test_method_selector_kinds(application)void" => block@2, method "test_method_overload(application)void" => block@3, method "test_arg_conversion(application)void" => block@4, method "test_15plus_args(application)void" => block@5, method "test_void(application)void" => block@6, method "test_ref_types(application,asset)void" => block@7, method "test_native_string(application)void" => block@8, method "test_native_bytes(application)void" => block@9, method "test_native_uint64(application)void" => block@10, method "test_native_biguint(application)void" => block@11, method "test_native_tuple(application)void" => block@12, method "test_no_args(application)void" => block@13, * => fail // reject transaction}
             block@2: // test_method_selector_kinds_route_L18
                 let tmp%2#0: uint64 = (txn OnCompletion)
                 let tmp%3#0: bool = (! tmp%2#0)
@@ -131,13 +131,24 @@ contract test_cases.typed_abi_call.typed_c2c.Greeter:
                 let tmp%70#0: uint64 = ((txnas Applications) tmp%69#0)
                 test_cases.typed_abi_call.typed_c2c.Greeter.test_native_tuple(tmp%70#0)
                 return 1u
-            block@15: // bare_routing_L17
+            block@13: // test_no_args_route_L215
                 let tmp%71#0: uint64 = (txn OnCompletion)
-                let not%tmp%71#0: bool = (! tmp%71#0)
-                (assert not%tmp%71#0) // reject transaction
-                let tmp%72#0: bool = (txn ApplicationID)
-                let tmp%73#0: bool = (! tmp%72#0)
-                (assert tmp%73#0) // is creating
+                let tmp%72#0: bool = (! tmp%71#0)
+                (assert tmp%72#0) // OnCompletion is NoOp
+                let tmp%73#0: bool = (txn ApplicationID)
+                (assert tmp%73#0) // is not creating
+                let tmp%74#0: bytes = (txna ApplicationArgs 1)
+                let tmp%75#0: uint64 = (btoi tmp%74#0)
+                let tmp%76#0: uint64 = ((txnas Applications) tmp%75#0)
+                test_cases.typed_abi_call.typed_c2c.Greeter.test_no_args(tmp%76#0)
+                return 1u
+            block@16: // bare_routing_L17
+                let tmp%77#0: uint64 = (txn OnCompletion)
+                let not%tmp%77#0: bool = (! tmp%77#0)
+                (assert not%tmp%77#0) // reject transaction
+                let tmp%78#0: bool = (txn ApplicationID)
+                let tmp%79#0: bool = (! tmp%78#0)
+                (assert tmp%79#0) // is creating
                 return 1u
 
         subroutine test_cases.typed_abi_call.typed_c2c.Greeter.test_method_selector_kinds(app: uint64) -> void:
@@ -709,6 +720,54 @@ contract test_cases.typed_abi_call.typed_c2c.Greeter:
                 let tmp%18#0: bool = (== result1#0 result3#0)
                 (assert tmp%18#0)
                 return 
+
+        subroutine test_cases.typed_abi_call.typed_c2c.Greeter.test_no_args(app: uint64) -> void:
+            block@0: // L215
+                itxn_begin
+                ((itxn_field ApplicationID) app#0)
+                ((itxn_field ApplicationArgs) method "no_args()uint64")
+                ((itxn_field TypeEnum) appl)
+                ((itxn_field Fee) 0u)
+                itxn_submit
+                let awst_tmp%0#0: bytes = (itxn LastLog)
+                let tmp%0#0: bytes = ((extract 4 0) awst_tmp%0#0)
+                let tmp%1#0: bytes = ((extract 0 4) awst_tmp%0#0)
+                let tmp%2#0: bool = (== tmp%1#0 0x151f7c75)
+                (assert tmp%2#0) // ARC4 prefix is valid
+                let result#0: uint64 = (btoi tmp%0#0)
+                let tmp%3#0: bool = (== result#0 42u)
+                (assert tmp%3#0)
+                itxn_begin
+                ((itxn_field ApplicationID) app#0)
+                ((itxn_field ApplicationArgs) method "no_args()uint64")
+                ((itxn_field TypeEnum) appl)
+                ((itxn_field Fee) 0u)
+                itxn_submit
+                let awst_tmp%1#0: bytes = (itxn LastLog)
+                let arc4_result#0: bytes = ((extract 4 0) awst_tmp%1#0)
+                let tmp%5#0: bytes = ((extract 0 4) awst_tmp%1#0)
+                let tmp%6#0: bool = (== tmp%5#0 0x151f7c75)
+                (assert tmp%6#0) // ARC4 prefix is valid
+                let tmp%7#0: bool = (b== arc4_result#0 0x000000000000002a)
+                (assert tmp%7#0)
+                itxn_begin
+                ((itxn_field ApplicationID) app#0)
+                ((itxn_field ApplicationArgs) method "no_args()uint64")
+                ((itxn_field TypeEnum) appl)
+                ((itxn_field Fee) 0u)
+                itxn_submit
+                let awst_tmp%2#0: bytes = (itxn LastLog)
+                let tmp%9#0: bytes = ((extract 0 4) awst_tmp%2#0)
+                let tmp%10#0: bool = (== tmp%9#0 0x151f7c75)
+                (assert tmp%10#0) // ARC4 prefix is valid
+                let awst_tmp%3#0: bytes = (itxn LastLog)
+                let tmp%12#0: bytes = ((extract 4 0) awst_tmp%3#0)
+                let tmp%13#0: bytes = ((extract 0 4) awst_tmp%3#0)
+                let tmp%14#0: bool = (== tmp%13#0 0x151f7c75)
+                (assert tmp%14#0) // ARC4 prefix is valid
+                let tmp%15#0: bool = (b== tmp%12#0 0x000000000000002a)
+                (assert tmp%15#0)
+                return 
 
     program clear-state:
         subroutine test_cases.typed_abi_call.typed_c2c.Greeter.clear_state_program() -> bool: