[flake8-bugbear] Implement quoted-fstring-value (B907)

crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B907.py

@@ -0,0 +1,200 @@
+def foo():
+ return "hello"
+
+
+var = var2 = "hello"
+
+# warnings
+f"begin '{var}' end"
+f"'{var}' end"
+f"begin '{var}'"
+
+f'begin "{var}" end'
+f'"{var}" end'
+f'begin "{var}"'
+
+f'a "{"hello"}" b'
+f'a "{foo()}" b'
+
+# fmt: off
+k = (f'"'
+ f'{var}'
+ f'"'
+ f'"')
+
+k = (f'"'
+ f'{var}'
+ '"'
+ f'"')
+
+k = ('"'
+ f'{var}'
+ '"')
+
+k = ('a'
+ f'{var}' # no warning
+ '"'
+ f'{var2}' # warning
+ '"')
+
+k = ('\''
+ f'{var}'
+ "'")
+
+k = ('"'
+ f'{var}'
+ "\"")
+
+k = (r'\"'
+ f'{var}'
+ r'"')
+# fmt: on
+
+f'{"hello"}"{var}"' # warn for var and not hello
+f'"{var}"{"hello"}' # warn for var and not hello
+f'"{var}" and {"hello"} and "{var2}"' # warn for var and var2
+f'"{var}" and "{var2}"' # warn for both
+f'"{var}""{var2}"' # warn for both
+
+# check that pre-quote & variable is reset if no post-quote is found
+f'"{var}abc "{var2}"' # warn on var2
+
+# check for escaped quotes
+f'\'{var}\''
+f'\"{var}\"'
+f"\'{var}\'"
+f"\"{var}\""
+
+# check formatting on different contained types
+f'"{var}"'
+f'"{var.__str__}"'
+f'"{var.__str__.__repr__}"'
+f'"{3+5}"'
+f'"{foo()}"'
+f'"{None}"'
+f'"{...}"' # although f'"{...!r}"' == 'Ellipsis'
+f'"{True}"'
+
+# various format strings
+# with "add type hint" suggestion
+f'"{var:}"'
+f'"{var:<}"'
+f'"{var:>}"'
+f'"{var:^}"'
+f'"{var:h<}"'
+f'"{var:h>}"'
+f'"{var:h^}"'
+f'"{var:s<}"'
+f'"{var:s>}"'
+f'"{var:s^}"'
+f'"{var:9}"'
+f'"{var:<9}"'
+f'"{var:>9}"'
+f'"{var:^9}"'
+f'"{var:h<9}"'
+f'"{var:19}"'
+f'"{var:<19}"'
+f'"{var:>19}"'
+f'"{var:^19}"'
+f'"{var:h<19}"'
+f'"{var:.}"'
+f'"{var:<.}"'
+f'"{var:>.}"'
+f'"{var:^.}"'
+f'"{var:h<.}"'
+f'"{var:9.}"'
+f'"{var:19.}"'
+f'"{var:.9}"'
+f'"{var:.19}"'
+# with "add !s" suggestion
+f'"{var:s}"'
+f'"{var:<s}"'
+f'"{var:>s}"'
+f'"{var:^s}"'
+f'"{var:h<s}"'
+f'"{var:9s}"'
+f'"{var:19s}"'
+f'"{var:.19s}"'
+
+# These all currently give warnings, but could be considered false alarms
+# multiple quote marks
+f'"""{var}"""'
+# two variables fighting over the same quote mark
+f'"{var}"{var2}"' # currently gives warning on the first one
+
+
+# ***no warnings*** #
+
+# str conversion specified
+f'"{var!s}"'
+
+# quote mark not immediately adjacent
+f'" {var} "'
+f'"{var} "'
+f'" {var}"'
+
+# mixed quote marks
+f"'{var}\""
+
+# repr specifier already given
+f'"{var!r}"'
+
+# two variables in a row with no quote mark inbetween
+f'"{var}{var}"'
+
+# don't crash on non-string constants
+f'5{var}"'
+f"\"{var}'"
+
+# sign option (only valid for number types)
+f'"{var:+}"'
+
+# integer presentation type specified
+f'"{var:b}"'
+f'"{var:c}"'
+f'"{var:d}"'
+f'"{var:o}"'
+f'"{var:x}"'
+f'"{var:X}"'
+f'"{var:n}"'
+
+# float presentation type
+f'"{var:e}"'
+f'"{var:E}"'
+f'"{var:f}"'
+f'"{var:F}"'
+f'"{var:g}"'
+f'"{var:G}"'
+f'"{var:n}"'
+f'"{var:%}"'
+
+# datetime presentation type
+f'"{var:%B %d, %Y}"'
+
+# alignment specifier invalid for strings
+f'"{var:=}"'
+
+# don't attempt to parse complex format specs
+f'"{var:{var}}"'
+f'"{var:5{var}}"'
+
+# even if explicit string type (not implemented)
+f'"{var:{var}s}"'
+
+# check for escaped non-quotes
+f'"{var}\\'
+# and be careful with raw strings and escaped characters
+rf'\"{var}\"'
+# fmt: off
+k = ('"'
+ f'{var}'
+ 'a')
+
+k = (r'\''
+ f'{var}'
+ r'\'')
+# fmt: on
+
+# check for debug formatting
+f'"{var=}"'
+

crates/ruff_linter/src/checkers/ast/analyze/expression.rs

@@ -1055,6 +1055,9 @@ pub(crate) fn expression(expr: &Expr, checker: &mut Checker) {
  if checker.enabled(Rule::HardcodedSQLExpression) {
  flake8_bandit::rules::hardcoded_sql_expression(checker, expr);
  }
+ if checker.enabled(Rule::QuotedFStringValue) {
+ flake8_bugbear::rules::quoted_fstring_value(checker, f_string_expr);
+ }
  if checker.enabled(Rule::UnicodeKindPrefix) {
  for string_literal in value.literals() {
  pyupgrade::rules::unicode_kind_prefix(checker, string_literal);

crates/ruff_linter/src/codes.rs

@@ -348,6 +348,7 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
  (Flake8Bugbear, "901") => (RuleGroup::Preview, rules::flake8_bugbear::rules::ReturnInGenerator),
  (Flake8Bugbear, "904") => (RuleGroup::Stable, rules::flake8_bugbear::rules::RaiseWithoutFromInsideExcept),
  (Flake8Bugbear, "905") => (RuleGroup::Stable, rules::flake8_bugbear::rules::ZipWithoutExplicitStrict),
+ (Flake8Bugbear, "907") => (RuleGroup::Preview, rules::flake8_bugbear::rules::QuotedFStringValue),
  (Flake8Bugbear, "909") => (RuleGroup::Preview, rules::flake8_bugbear::rules::LoopIteratorMutation),
 
  // flake8-blind-except

crates/ruff_linter/src/rules/flake8_bugbear/mod.rs

@@ -63,6 +63,7 @@ mod tests {
  #[test_case(Rule::UselessExpression, Path::new("B018.ipynb"))]
  #[test_case(Rule::UselessExpression, Path::new("B018.py"))]
  #[test_case(Rule::ReturnInGenerator, Path::new("B901.py"))]
+ #[test_case(Rule::QuotedFStringValue, Path::new("B907.py"))]
  #[test_case(Rule::LoopIteratorMutation, Path::new("B909.py"))]
  fn rules(rule_code: Rule, path: &Path) -> Result<()> {
  let snapshot = format!("{}_{}", rule_code.noqa_code(), path.to_string_lossy());

crates/ruff_linter/src/rules/flake8_bugbear/rules/mod.rs

@@ -16,6 +16,7 @@ pub(crate) use loop_iterator_mutation::*;
 pub(crate) use loop_variable_overrides_iterator::*;
 pub(crate) use mutable_argument_default::*;
 pub(crate) use no_explicit_stacklevel::*;
+pub(crate) use quoted_fstring_value::*;
 pub(crate) use raise_literal::*;
 pub(crate) use raise_without_from_inside_except::*;
 pub(crate) use re_sub_positional_args::*;
@@ -53,6 +54,7 @@ mod loop_iterator_mutation;
 mod loop_variable_overrides_iterator;
 mod mutable_argument_default;
 mod no_explicit_stacklevel;
+mod quoted_fstring_value;
 mod raise_literal;
 mod raise_without_from_inside_except;
 mod re_sub_positional_args;