Add better type deduction to use-pathlib-is-funcs and `use-pathlib-…

…stat` checks

refurb/checks/pathlib/getsize.py

@@ -1,8 +1,8 @@
 from dataclasses import dataclass
 
-from mypy.nodes import BytesExpr, CallExpr, NameExpr, RefExpr, StrExpr, Var
+from mypy.nodes import CallExpr, RefExpr
 
-from refurb.checks.common import is_same_type, normalize_os_path
+from refurb.checks.common import get_mypy_type, is_same_type, normalize_os_path
 from refurb.checks.pathlib.util import is_pathlike
 from refurb.error import Error
 
@@ -52,21 +52,14 @@ def check(node: CallExpr, errors: list[Error]) -> None:
                 return
 
             if is_pathlike(arg):
-                replace = f"x.{new_name}"
+                new = f"x.{new_name}"
 
-            else:
-                match arg:
-                    case BytesExpr() | StrExpr():
-                        pass
-
-                    case NameExpr(node=Var(type=ty)) if is_same_type(ty, str, bytes):
-                        pass
+            elif is_same_type(get_mypy_type(arg), str, bytes):
+                new = f"Path(x).{new_name}"
 
-                    case _:
-                        return
+            else:
+                return
 
-                replace = f"Path(x).{new_name}"
+            msg = f"Replace `{normalized_name}(x)` with `{new}`"
 
-            errors.append(
-                ErrorInfo.from_node(node, f"Replace `{normalized_name}(x)` with `{replace}`")
-            )
+            errors.append(ErrorInfo.from_node(node, msg))

refurb/checks/pathlib/is_file.py

@@ -1,8 +1,8 @@
 from dataclasses import dataclass
 
-from mypy.nodes import BytesExpr, CallExpr, NameExpr, RefExpr, StrExpr, Var
+from mypy.nodes import CallExpr, RefExpr
 
-from refurb.checks.common import is_same_type, normalize_os_path
+from refurb.checks.common import get_mypy_type, is_same_type, normalize_os_path
 from refurb.checks.pathlib.util import is_pathlike
 from refurb.error import Error
 
@@ -51,21 +51,14 @@ def check(node: CallExpr, errors: list[Error]) -> None:
                 return
 
             if is_pathlike(arg):
-                replace = f"x.{new_name}()"
+                new = f"x.{new_name}()"
 
-            else:
-                match arg:
-                    case BytesExpr() | StrExpr():
-                        pass
-
-                    case NameExpr(node=Var(type=ty)) if is_same_type(ty, str, bytes):
-                        pass
+            elif is_same_type(get_mypy_type(arg), str, bytes):
+                new = f"Path(x).{new_name}()"
 
-                    case _:
-                        return
+            else:
+                return
 
-                replace = f"Path(x).{new_name}()"
+            msg = f"Replace `{normalized_name}(x)` with `{new}`"
 
-            errors.append(
-                ErrorInfo.from_node(node, f"Replace `{normalized_name}(x)` with `{replace}`")
-            )
+            errors.append(ErrorInfo.from_node(node, msg))

test/data/err_146.py

@@ -38,6 +38,12 @@
 isfile("filename")
 islink("filename")
 
+class C:
+    p: str
+
+isfile(C().p)
+
+
 # these should not
 
 os.path.ismount("somefile")

test/data/err_146.txt

@@ -22,3 +22,4 @@ test/data/err_146.py:36:1 [FURB146]: Replace `os.path.isabs(x)` with `Path(x).is
 test/data/err_146.py:37:1 [FURB146]: Replace `os.path.isdir(x)` with `Path(x).is_dir()`
 test/data/err_146.py:38:1 [FURB146]: Replace `os.path.isfile(x)` with `Path(x).is_file()`
 test/data/err_146.py:39:1 [FURB146]: Replace `os.path.islink(x)` with `Path(x).is_symlink()`
+test/data/err_146.py:44:1 [FURB146]: Replace `os.path.isfile(x)` with `Path(x).is_file()`

test/data/err_155.py

@@ -25,5 +25,11 @@
 os.path.getsize(__file__)
 getsize("filename")
 
+class C:
+    s: str
+
+getsize(C().s)
+
+
 # this should not match
 os.path.getsize(1)

test/data/err_155.txt

@@ -15,3 +15,4 @@ test/data/err_155.py:23:1 [FURB155]: Replace `os.path.getsize(x)` with `Path(x).
 test/data/err_155.py:24:1 [FURB155]: Replace `os.path.getsize(x)` with `x.stat().st_size`
 test/data/err_155.py:25:1 [FURB155]: Replace `os.path.getsize(x)` with `Path(x).stat().st_size`
 test/data/err_155.py:26:1 [FURB155]: Replace `os.path.getsize(x)` with `Path(x).stat().st_size`
+test/data/err_155.py:31:1 [FURB155]: Replace `os.path.getsize(x)` with `Path(x).stat().st_size`