Ignore string literals in f-strings #3548 (#3551)

Co-authored-by: marat <[email protected]>

Author: F0RRZZ

CHANGELOG.md

@@ -30,6 +30,10 @@ Semantic versioning in our case means:
 
 - Adds `WPS365`: match statement can be simplified to `if`, #3520
 
+### Bugfixes
+
+- Fixes `WPS226` false-positive on fstring parts, #3548
+
 
 ## 1.4.0
 

tests/test_visitors/test_ast/test_complexity/test_overuses/test_overused_string.py

@@ -96,6 +96,16 @@ def function() -> Dict[int, {0}]:
     ...
 """
 
+fstring_same_prefix1 = """
+x = f'Hello, {pattern}'
+y = f'Hello, {pattern}'
+"""
+
+fstring_same_prefix2 = """
+x = f'{pattern}-postfix'
+y = f'{pattern}-postfix'
+"""
+
 EXPECTED_LOCATION = (2, 8)
 
 
@@ -257,3 +267,25 @@ def test_common_strings_allowed(
     visitor.run()
 
     assert_errors(visitor, [])
+
+
+@pytest.mark.parametrize(
+    'strings',
+    [
+        fstring_same_prefix1,
+        fstring_same_prefix2,
+    ],
+)
+def test_fstring_strings_not_counted(
+    assert_errors,
+    parse_ast_tree,
+    options,
+    strings,
+):
+    """Ensures that string literals inside f-strings are not overused."""
+    tree = parse_ast_tree(strings)
+    option_values = options(max_string_usages=1)
+    visitor = StringOveruseVisitor(option_values, tree=tree)
+    visitor.run()
+
+    assert_errors(visitor, [])

wemake_python_styleguide/visitors/ast/complexity/overuses.py

@@ -81,6 +81,10 @@ def _check_string_constant(self, node: ast.Constant) -> None:
         if annotations.is_annotation(node):
             return
 
+        # Part of the f-string:
+        if walk.get_closest_parent(node, parents=(ast.JoinedStr,)):
+            return
+
         # Some strings are so common, that it makes no sense to check if
         # they are overused.
         if (