chore(frontend-python): add test for runtime compiled function

frontends/concrete-python/tests/dtypes/test_tfhers.py

@@ -5,11 +5,14 @@ Tests of `TFHERSIntegerType` data type.
 import json
 import os
 import tempfile
+from functools import partial
+from types import FunctionType
 
 import numpy as np
 import pytest
 
 from concrete.fhe import tfhers
+from concrete.fhe.compilation.compiler import Compiler
 
 DEFAULT_TFHERS_PARAM = tfhers.CryptoParams(
     909,
@@ -198,3 +201,50 @@ def test_load_tfhers_params_file(params_dict):
 
     tfhers.get_type_from_params(fpath, True, 8)
     os.unlink(fpath)
+
+
+@pytest.mark.parametrize("n_args", [1, 3])
+def test_compile_runtime_defined_function(n_args):
+    arg_names = [chr(v) for v in range(ord("a"), ord("a") + n_args)]
+    proxy_func_arg_string = ", ".join(arg_names)
+    proxy_func_name = "_proxy"
+
+    dtype = tfhers.uint8_2_2(DEFAULT_TFHERS_PARAM)
+
+    def function_to_proxy_3(a, b, c):
+        return a + b + c
+
+    def function_to_proxy_1(a):
+        return a + a
+
+    func_to_proxy_str = "function_to_proxy_1" if n_args == 1 else "function_to_proxy_3"
+
+    function_to_proxy_code_str = (
+        f"def {proxy_func_name}({proxy_func_arg_string}): \n"
+        f"  from concrete.fhe import tfhers\n"
+        f"  native_inputs = tuple((tfhers.to_native(v) for v in [{proxy_func_arg_string}]))\n"
+        f"  res = {func_to_proxy_str}(*native_inputs)\n"
+        f"  out = tuple((tfhers.from_native(v, dtype) for v in res)) if isinstance(res, tuple) else tfhers.from_native(res, dtype) \n"
+        f"  return out"
+    )
+
+    function_proxy_code = compile(
+        function_to_proxy_code_str,
+        __file__,
+        mode="exec",
+    )
+    function_proxy = FunctionType(function_proxy_code.co_consts[0], locals(), proxy_func_name)
+
+    inputs_encryption_status = {v: "encrypted" for v in arg_names}
+
+    compiler = Compiler(
+        function_proxy,
+        parameter_encryption_statuses=inputs_encryption_status,
+    )
+
+    input_vals = list(range(1, n_args + 1))
+    inputset = [tuple(tfhers.TFHERSInteger(dtype, v) for v in input_vals)]
+
+    compiler.compile(
+        inputset,
+    )