Delay actually loading the runtime to fix property setting (#63)

* Delay actually loading the runtime to fix property setting
* Launch test for properties in separate process

clr_loader/hostfxr.py

@@ -20,9 +20,8 @@ def __init__(self, runtime_config: Path, dotnet_root: Path, **params: str):
 
         self._dotnet_root = Path(dotnet_root)
         self._dll = load_hostfxr(self._dotnet_root)
-        self._is_initialized = False
         self._handle = _get_handle(self._dll, self._dotnet_root, runtime_config)
-        self._load_func = _get_load_func(self._dll, self._handle)
+        self._load_func = None
 
         for key, value in params.items():
             self[key] = value
@@ -36,7 +35,7 @@ def dotnet_root(self) -> Path:
 
     @property
     def is_initialized(self) -> bool:
-        return self._is_initialized
+        return self._load_func is not None
 
     @property
     def is_shutdown(self) -> bool:
@@ -81,18 +80,23 @@ def __iter__(self) -> Generator[Tuple[str, str], None, None]:
         for i in range(size_ptr[0]):
             yield (decode(keys_ptr[i]), decode(values_ptr[i]))
 
+    def _get_load_func(self):
+        if self._load_func is None:
+            self._load_func = _get_load_func(self._dll, self._handle)
+
+        return self._load_func
+
     def _get_callable(self, assembly_path: StrOrPath, typename: str, function: str):
         # TODO: Maybe use coreclr_get_delegate as well, supported with newer API
         # versions of hostfxr
-        self._is_initialized = True
 
         # Append assembly name to typename
         assembly_path = Path(assembly_path)
         assembly_name = assembly_path.stem
         typename = f"{typename}, {assembly_name}"
 
         delegate_ptr = ffi.new("void**")
-        res = self._load_func(
+        res = self._get_load_func()(
             encode(str(assembly_path)),
             encode(typename),
             encode(function),
@@ -103,12 +107,6 @@ def _get_callable(self, assembly_path: StrOrPath, typename: str, function: str):
         check_result(res)
         return ffi.cast("component_entry_point_fn", delegate_ptr[0])
 
-    def _check_initialized(self) -> None:
-        if self._handle is None:
-            raise RuntimeError("Runtime is shut down")
-        elif not self._is_initialized:
-            raise RuntimeError("Runtime is not initialized")
-
     def shutdown(self) -> None:
         if self._handle is not None:
             self._dll.hostfxr_close(self._handle)

tests/test_common.py

@@ -18,7 +18,7 @@ def example_netcore(tmpdir_factory):
 
 def build_example(tmpdir_factory, framework):
     out = Path(tmpdir_factory.mktemp(f"example-{framework}"))
-    proj_path = Path(__file__).parent.parent / "example"
+    proj_path = Path(__file__).parent.parent / "example" / "example.csproj"
 
     check_call(["dotnet", "build", str(proj_path), "-o", str(out), "-f", framework])
 
@@ -75,6 +75,19 @@ def test_coreclr(example_netcore: Path):
     run_tests(asm)
 
 
+def test_coreclr_properties(example_netcore: Path):
+    from multiprocessing import get_context
+
+    p = get_context("spawn").Process(
+        target=_do_test_coreclr_autogenerated_runtimeconfig,
+        args=(example_netstandard,),
+        kwargs=dict(properties=dict(APP_CONTEXT_BASE_DIRECTORY=str(example_netcore))),
+    )
+    p.start()
+    p.join()
+    p.close()
+
+
 def test_coreclr_autogenerated_runtimeconfig(example_netstandard: Path):
     from multiprocessing import get_context
 
@@ -86,10 +99,12 @@ def test_coreclr_autogenerated_runtimeconfig(example_netstandard: Path):
     p.close()
 
 
-def _do_test_coreclr_autogenerated_runtimeconfig(example_netstandard: Path):
+def _do_test_coreclr_autogenerated_runtimeconfig(
+    example_netstandard: Path, **properties
+):
     from clr_loader import get_coreclr
 
-    coreclr = get_coreclr()
+    coreclr = get_coreclr(properties=properties)
     asm = coreclr.get_assembly(example_netstandard / "example.dll")
 
     run_tests(asm)