Fix circular imports for wiring.intercept

Strangely, I can't seem to reproduce this error in
the test suite.

Author: scottzach1

pif/providers/__init__.py

@@ -1,5 +1,6 @@
+# isort: skip_file
+from pif.providers.provider import Provider
 from pif.providers.blank import Blank
 from pif.providers.existing_singleton import ExistingSingleton
 from pif.providers.factory import Factory
-from pif.providers.provider import Provider
 from pif.providers.singleton import Singleton

pif/providers/factory.py

@@ -12,7 +12,7 @@
 from typing import Callable
 
 from pif.providers.provider import Provider
-from pif.wiring import intercept
+from pif.providers.util import intercept_args
 
 
 class Factory[T](Provider):
@@ -23,7 +23,7 @@ class Factory[T](Provider):
     __slots__ = ("_func", "_depends")
 
     def __init__(self, func: Callable[[...], T], *args, **kwargs):
-        self._func = functools.partial(intercept(func), *args, **kwargs)
+        self._func = functools.partial(intercept_args(func), *args, **kwargs)
 
     def _evaluate(self) -> T:
         return self._func()

pif/providers/provider.py

@@ -47,7 +47,7 @@ def override_existing[U](self, value: U) -> Override[Provider[T]]:
         """
         Override the current provider with an existing singleton.
         """
-        from .existing_singleton import ExistingSingleton
+        from pif.providers.existing_singleton import ExistingSingleton
 
         return self.override(ExistingSingleton(value))
 

pif/providers/singleton.py

@@ -12,7 +12,7 @@
 from typing import Callable
 
 from pif.providers.provider import Provider
-from pif.wiring import intercept
+from pif.providers.util import intercept_args
 
 UNSET = object()
 
@@ -27,7 +27,7 @@ class Singleton[T](Provider):
     __slots__ = ("_func", "_func", "_result", "_depends")
 
     def __init__(self, func: Callable[[...], T], *args, **kwargs):
-        self._func = functools.partial(intercept(func), *args, **kwargs)
+        self._func = functools.partial(intercept_args(func), *args, **kwargs)
         self._result = UNSET
 
     def _evaluate(self) -> T:

pif/providers/util.py

@@ -0,0 +1,20 @@
+import functools
+
+from pif.providers.provider import Provider
+
+
+def intercept_args(func):
+    """
+    Intercepts the args and kwargs at runtime evaluating any Provider values.
+
+    Kept separate to wiring.py to avoid circular imports.
+    """
+
+    @functools.wraps(func)
+    def wrapper(*args, **kwargs):
+        return func(
+            *(a() if isinstance(a, Provider) else a for a in args),
+            **{k: v() if isinstance(v, Provider) else v for k, v in kwargs.items()},
+        )
+
+    return wrapper