[refurb] Implement slice-to-remove-prefix-or-suffix (FURB188) (as…

…tral-sh#13256)

crates/ruff_linter/resources/test/fixtures/refurb/FURB188.py

@@ -0,0 +1,154 @@
+# Test suite from Refurb
+# See https://github.com/dosisod/refurb/blob/db02242b142285e615a664a8d3324470bb711306/test/data/err_188.py
+
+# these should match
+
+def remove_extension_via_slice(filename: str) -> str:
+    if filename.endswith(".txt"):
+        filename = filename[:-4]
+
+    return filename
+
+
+def remove_extension_via_slice_len(filename: str, extension: str) -> str:
+    if filename.endswith(extension):
+        filename = filename[:-len(extension)]
+
+    return filename
+
+
+def remove_extension_via_ternary(filename: str) -> str:
+    return filename[:-4] if filename.endswith(".txt") else filename
+
+
+def remove_extension_via_ternary_with_len(filename: str, extension: str) -> str:
+    return filename[:-len(extension)] if filename.endswith(extension) else filename
+
+
+def remove_prefix(filename: str) -> str:
+    return filename[4:] if filename.startswith("abc-") else filename
+
+
+def remove_prefix_via_len(filename: str, prefix: str) -> str:
+    return filename[len(prefix):] if filename.startswith(prefix) else filename
+
+
+# these should not
+
+def remove_extension_with_mismatched_len(filename: str) -> str:
+    if filename.endswith(".txt"):
+        filename = filename[:3]
+
+    return filename
+
+
+def remove_extension_assign_to_different_var(filename: str) -> str:
+    if filename.endswith(".txt"):
+        other_var = filename[:-4]
+
+    return filename
+
+
+def remove_extension_with_multiple_stmts(filename: str) -> str:
+    if filename.endswith(".txt"):
+        print("do some work")
+
+        filename = filename[:-4]
+
+    if filename.endswith(".txt"):
+        filename = filename[:-4]
+
+        print("do some work")
+
+    return filename
+
+
+def remove_extension_from_unrelated_var(filename: str) -> str:
+    xyz = "abc.txt"
+
+    if filename.endswith(".txt"):
+        filename = xyz[:-4]
+
+    return filename
+
+
+def remove_extension_in_elif(filename: str) -> str:
+    if filename:
+        pass
+
+    elif filename.endswith(".txt"):
+        filename = filename[:-4]
+
+    return filename
+
+
+def remove_extension_in_multiple_elif(filename: str) -> str:
+    if filename:
+        pass
+
+    elif filename:
+        pass
+
+    elif filename.endswith(".txt"):
+        filename = filename[:-4]
+
+    return filename
+
+
+def remove_extension_in_if_with_else(filename: str) -> str:
+    if filename.endswith(".txt"):
+        filename = filename[:-4]
+
+    else:
+        pass
+
+    return filename
+
+
+def remove_extension_ternary_name_mismatch(filename: str):
+    xyz = ""
+
+    _ = xyz[:-4] if filename.endswith(".txt") else filename
+    _ = filename[:-4] if xyz.endswith(".txt") else filename
+    _ = filename[:-4] if filename.endswith(".txt") else xyz
+
+
+def remove_extension_slice_amount_mismatch(filename: str) -> None:
+    extension = ".txt"
+
+    _ = filename[:-1] if filename.endswith(".txt") else filename
+    _ = filename[:-1] if filename.endswith(extension) else filename
+    _ = filename[:-len("")] if filename.endswith(extension) else filename
+
+
+def remove_prefix_size_mismatch(filename: str) -> str:
+    return filename[3:] if filename.startswith("abc-") else filename
+
+
+def remove_prefix_name_mismatch(filename: str) -> None:
+    xyz = ""
+
+    _ = xyz[4:] if filename.startswith("abc-") else filename
+    _ = filename[4:] if xyz.startswith("abc-") else filename
+    _ = filename[4:] if filename.startswith("abc-") else xyz
+
+# ---- End of refurb test suite ---- #
+
+# ---- Begin ruff specific test suite --- #
+
+# these should be linted
+
+def remove_suffix_multiple_attribute_expr() -> None:
+    import foo.bar
+
+    SUFFIX = "suffix"
+
+    x = foo.bar.baz[:-len(SUFFIX)] if foo.bar.baz.endswith(SUFFIX) else foo.bar.baz
+
+def remove_prefix_comparable_literal_expr() -> None:
+    return ("abc" "def")[3:] if ("abc" "def").startswith("abc") else "abc" "def"
+
+def shadow_builtins(filename: str, extension: str) -> None:
+    from builtins import len as builtins_len
+
+    return filename[:-builtins_len(extension)] if filename.endswith(extension) else filename

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

@@ -1407,6 +1407,9 @@ pub(crate) fn expression(expr: &Expr, checker: &mut Checker) {
             if checker.enabled(Rule::UselessIfElse) {
                 ruff::rules::useless_if_else(checker, if_exp);
             }
+            if checker.enabled(Rule::SliceToRemovePrefixOrSuffix) {
+                refurb::rules::slice_to_remove_affix_expr(checker, if_exp);
+            }
         }
         Expr::ListComp(
             comp @ ast::ExprListComp {

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

@@ -1178,6 +1178,9 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
             if checker.enabled(Rule::CheckAndRemoveFromSet) {
                 refurb::rules::check_and_remove_from_set(checker, if_);
             }
+            if checker.enabled(Rule::SliceToRemovePrefixOrSuffix) {
+                refurb::rules::slice_to_remove_affix_stmt(checker, if_);
+            }
             if checker.enabled(Rule::TooManyBooleanExpressions) {
                 pylint::rules::too_many_boolean_expressions(checker, if_);
             }

crates/ruff_linter/src/codes.rs

@@ -1067,6 +1067,7 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
         (Refurb, "180") => (RuleGroup::Preview, rules::refurb::rules::MetaClassABCMeta),
         (Refurb, "181") => (RuleGroup::Stable, rules::refurb::rules::HashlibDigestHex),
         (Refurb, "187") => (RuleGroup::Stable, rules::refurb::rules::ListReverseCopy),
+        (Refurb, "188") => (RuleGroup::Preview, rules::refurb::rules::SliceToRemovePrefixOrSuffix),
         (Refurb, "192") => (RuleGroup::Preview, rules::refurb::rules::SortedMinMax),
 
         // flake8-logging

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

@@ -46,6 +46,7 @@ mod tests {
     #[test_case(Rule::WriteWholeFile, Path::new("FURB103.py"))]
     #[test_case(Rule::FStringNumberFormat, Path::new("FURB116.py"))]
     #[test_case(Rule::SortedMinMax, Path::new("FURB192.py"))]
+    #[test_case(Rule::SliceToRemovePrefixOrSuffix, Path::new("FURB188.py"))]
     fn rules(rule_code: Rule, path: &Path) -> Result<()> {
         let snapshot = format!("{}_{}", rule_code.noqa_code(), path.to_string_lossy());
         let diagnostics = test_path(

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

@@ -23,6 +23,7 @@ pub(crate) use repeated_append::*;
 pub(crate) use repeated_global::*;
 pub(crate) use single_item_membership_test::*;
 pub(crate) use slice_copy::*;
+pub(crate) use slice_to_remove_prefix_or_suffix::*;
 pub(crate) use sorted_min_max::*;
 pub(crate) use type_none_comparison::*;
 pub(crate) use unnecessary_enumerate::*;
@@ -55,6 +56,7 @@ mod repeated_append;
 mod repeated_global;
 mod single_item_membership_test;
 mod slice_copy;
+mod slice_to_remove_prefix_or_suffix;
 mod sorted_min_max;
 mod type_none_comparison;
 mod unnecessary_enumerate;