Add recognition of previous partial args/kwargs when chaining (#1209)

* Add recognition of previous partial args/kwargs when chaining

Repeat use of functools.partial on the same function would only
keep the args & kwargs locked in by the last call to partial.
By checking if the wrapped function is itself a partial, and
including its filled args/kwargs if it is, we can keep track
of all locked args/kwargs across any number of nested partial
calls.

Co-authored-by: Pierre Sassoulas <pierre.sassoulas@gmail.com>

1 files changed, 11 insertions, 1 deletions

diff --git a/astroid/objects.py b/astroid/objects.py
index 4241c170..ba2e4178 100644
--- a/astroid/objects.py
+++ b/astroid/objects.py
@@ -265,10 +265,20 @@ class PartialFunction(scoped_nodes.FunctionDef):
         # A typical FunctionDef automatically adds its name to the parent scope,
         # but a partial should not, so defer setting parent until after init
         self.parent = parent
-        self.filled_positionals = len(call.positional_arguments[1:])
         self.filled_args = call.positional_arguments[1:]
         self.filled_keywords = call.keyword_arguments
 
+        wrapped_function = call.positional_arguments[0]
+        inferred_wrapped_function = next(wrapped_function.infer())
+        if isinstance(inferred_wrapped_function, PartialFunction):
+            self.filled_args = inferred_wrapped_function.filled_args + self.filled_args
+            self.filled_keywords = {
+                **inferred_wrapped_function.filled_keywords,
+                **self.filled_keywords,
+            }
+
+        self.filled_positionals = len(self.filled_args)
+
     def infer_call_result(self, caller=None, context=None):
         if context:
             current_passed_keywords = {