Implement C414

README.md

@@ -215,7 +215,7 @@ ruff also implements some of the most popular Flake8 plugins natively, including
 - [`flake8-builtins`](https://pypi.org/project/flake8-builtins/)
 - [`flake8-super`](https://pypi.org/project/flake8-super/)
 - [`flake8-print`](https://pypi.org/project/flake8-print/)
-- [`flake8-comprehensions`](https://pypi.org/project/flake8-comprehensions/) (11/16)
+- [`flake8-comprehensions`](https://pypi.org/project/flake8-comprehensions/) (12/16)
 - [`flake8-bugbear`](https://pypi.org/project/flake8-bugbear/) (3/32)
 - [`flake8-docstrings`](https://pypi.org/project/flake8-docstrings/) (17/48)
 - [`pyupgrade`](https://pypi.org/project/pyupgrade/) (8/34)
@@ -293,6 +293,7 @@ The 🛠 emoji indicates that a rule is automatically fixable by the `--fix` com
 | C408 | UnnecessaryCollectionCall | Unnecessary <dict/list/tuple> call - rewrite as a literal |  |  |
 | C409 | UnnecessaryLiteralWithinTupleCall | Unnecessary <list/tuple> literal passed to tuple() - remove the outer call to tuple() |  |  |
 | C410 | UnnecessaryLiteralWithinListCall | Unnecessary <list/tuple> literal passed to list() - rewrite as a list literal |  |  |
+| C414 | UnnecessaryDoubleCastOrProcess | Unnecessary <list/reversed/set/sorted/tuple> call within <list/set/sorted/tuple>(). |  |  |
 | C415 | UnnecessarySubscriptReversal | Unnecessary subscript reversal of iterable within <reversed/set/sorted>() |  |  |
 | T201 | PrintFound | `print` found |  | 🛠 |
 | T203 | PPrintFound | `pprint` found |  | 🛠 |

resources/test/fixtures/C414.py

@@ -0,0 +1,14 @@
+x = [1, 2, 3]
+list(list(x))
+list(tuple(x))
+tuple(list(x))
+tuple(tuple(x))
+set(set(x))
+set(list(x))
+set(tuple(x))
+set(sorted(x))
+set(reversed(x))
+sorted(list(x))
+sorted(tuple(x))
+sorted(sorted(x))
+sorted(reversed(x))

src/ast/checkers.rs

@@ -1004,6 +1004,68 @@ pub fn unnecessary_literal_within_list_call(
     None
 }
 
+pub fn unnecessary_double_cast_or_process(
+    expr: &Expr,
+    func: &Expr,
+    args: &[Expr],
+) -> Option<Check> {
+    if let ExprKind::Name { id: outer, .. } = &func.node {
+        if outer == "list"
+            || outer == "tuple"
+            || outer == "set"
+            || outer == "reversed"
+            || outer == "sorted"
+        {
+            if let Some(arg) = args.first() {
+                if let ExprKind::Call { func, .. } = &arg.node {
+                    if let ExprKind::Name { id: inner, .. } = &func.node {
+                        // Ex) set(tuple(...))
+                        if (outer == "set" || outer == "sorted")
+                            && (inner == "list"
+                                || inner == "tuple"
+                                || inner == "reversed"
+                                || inner == "sorted")
+                        {
+                            return Some(Check::new(
+                                CheckKind::UnnecessaryDoubleCastOrProcess(
+                                    inner.to_string(),
+                                    outer.to_string(),
+                                ),
+                                Range::from_located(expr),
+                            ));
+                        }
+
+                        // Ex) list(tuple(...))
+                        if (outer == "list" || outer == "tuple")
+                            && (inner == "list" || inner == "tuple")
+                        {
+                            return Some(Check::new(
+                                CheckKind::UnnecessaryDoubleCastOrProcess(
+                                    inner.to_string(),
+                                    outer.to_string(),
+                                ),
+                                Range::from_located(expr),
+                            ));
+                        }
+
+                        // Ex) set(set(...))
+                        if outer == "set" && inner == "set" {
+                            return Some(Check::new(
+                                CheckKind::UnnecessaryDoubleCastOrProcess(
+                                    inner.to_string(),
+                                    outer.to_string(),
+                                ),
+                                Range::from_located(expr),
+                            ));
+                        }
+                    }
+                }
+            }
+        }
+    }
+    None
+}
+
 pub fn unnecessary_subscript_reversal(expr: &Expr, func: &Expr, args: &[Expr]) -> Option<Check> {
     if let Some(first_arg) = args.first() {
         if let ExprKind::Name { id, .. } = &func.node {

src/check_ast.rs

@@ -837,6 +837,15 @@ where
                         self.checks.push(check);
                     };
                 }
+
+                if self.settings.enabled.contains(&CheckCode::C414) {
+                    if let Some(check) =
+                        checkers::unnecessary_double_cast_or_process(expr, func, args)
+                    {
+                        self.checks.push(check);
+                    };
+                }
+
                 if self.settings.enabled.contains(&CheckCode::C415) {
                     if let Some(check) = checkers::unnecessary_subscript_reversal(expr, func, args)
                     {

src/checks.rs

@@ -137,6 +137,7 @@ pub enum CheckCode {
     C408,
     C409,
     C410,
+    C414,
     C415,
     // flake8-print
     T201,
@@ -251,6 +252,7 @@ pub enum CheckKind {
     UnnecessaryCollectionCall(String),
     UnnecessaryLiteralWithinTupleCall(String),
     UnnecessaryLiteralWithinListCall(String),
+    UnnecessaryDoubleCastOrProcess(String, String),
     UnnecessarySubscriptReversal(String),
     // flake8-print
     PrintFound,
@@ -372,6 +374,10 @@ impl CheckCode {
             CheckCode::C410 => {
                 CheckKind::UnnecessaryLiteralWithinListCall("<list/tuple>".to_string())
             }
+            CheckCode::C414 => CheckKind::UnnecessaryDoubleCastOrProcess(
+                "<list/reversed/set/sorted/tuple>".to_string(),
+                "<list/set/sorted/tuple>".to_string(),
+            ),
             CheckCode::C415 => {
                 CheckKind::UnnecessarySubscriptReversal("<reversed/set/sorted>".to_string())
             }
@@ -482,6 +488,7 @@ impl CheckKind {
             CheckKind::UnnecessaryCollectionCall(_) => &CheckCode::C408,
             CheckKind::UnnecessaryLiteralWithinTupleCall(..) => &CheckCode::C409,
             CheckKind::UnnecessaryLiteralWithinListCall(..) => &CheckCode::C410,
+            CheckKind::UnnecessaryDoubleCastOrProcess(..) => &CheckCode::C414,
             CheckKind::UnnecessarySubscriptReversal(_) => &CheckCode::C415,
             // flake8-print
             CheckKind::PrintFound => &CheckCode::T201,
@@ -725,6 +732,9 @@ impl CheckKind {
                     )
                 }
             }
+            CheckKind::UnnecessaryDoubleCastOrProcess(inner, outer) => {
+                format!("Unnecessary {inner} call within {outer}().")
+            }
             CheckKind::UnnecessarySubscriptReversal(func) => {
                 format!("Unnecessary subscript reversal of iterable within {func}()")
             }

src/linter.rs

@@ -996,6 +996,18 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn c414() -> Result<()> {
+        let mut checks = check_path(
+            Path::new("./resources/test/fixtures/C414.py"),
+            &settings::Settings::for_rule(CheckCode::C414),
+            &fixer::Mode::Generate,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(checks);
+        Ok(())
+    }
+
     #[test]
     fn c415() -> Result<()> {
         let mut checks = check_path(

src/snapshots/ruff__linter__tests__c414.snap

@@ -0,0 +1,148 @@
+---
+source: src/linter.rs
+expression: checks
+---
+- kind:
+    UnnecessaryDoubleCastOrProcess:
+      - list
+      - list
+  location:
+    row: 2
+    column: 1
+  end_location:
+    row: 2
+    column: 14
+  fix: ~
+- kind:
+    UnnecessaryDoubleCastOrProcess:
+      - tuple
+      - list
+  location:
+    row: 3
+    column: 1
+  end_location:
+    row: 3
+    column: 15
+  fix: ~
+- kind:
+    UnnecessaryDoubleCastOrProcess:
+      - list
+      - tuple
+  location:
+    row: 4
+    column: 1
+  end_location:
+    row: 4
+    column: 15
+  fix: ~
+- kind:
+    UnnecessaryDoubleCastOrProcess:
+      - tuple
+      - tuple
+  location:
+    row: 5
+    column: 1
+  end_location:
+    row: 5
+    column: 16
+  fix: ~
+- kind:
+    UnnecessaryDoubleCastOrProcess:
+      - set
+      - set
+  location:
+    row: 6
+    column: 1
+  end_location:
+    row: 6
+    column: 12
+  fix: ~
+- kind:
+    UnnecessaryDoubleCastOrProcess:
+      - list
+      - set
+  location:
+    row: 7
+    column: 1
+  end_location:
+    row: 7
+    column: 13
+  fix: ~
+- kind:
+    UnnecessaryDoubleCastOrProcess:
+      - tuple
+      - set
+  location:
+    row: 8
+    column: 1
+  end_location:
+    row: 8
+    column: 14
+  fix: ~
+- kind:
+    UnnecessaryDoubleCastOrProcess:
+      - sorted
+      - set
+  location:
+    row: 9
+    column: 1
+  end_location:
+    row: 9
+    column: 15
+  fix: ~
+- kind:
+    UnnecessaryDoubleCastOrProcess:
+      - reversed
+      - set
+  location:
+    row: 10
+    column: 1
+  end_location:
+    row: 10
+    column: 17
+  fix: ~
+- kind:
+    UnnecessaryDoubleCastOrProcess:
+      - list
+      - sorted
+  location:
+    row: 11
+    column: 1
+  end_location:
+    row: 11
+    column: 16
+  fix: ~
+- kind:
+    UnnecessaryDoubleCastOrProcess:
+      - tuple
+      - sorted
+  location:
+    row: 12
+    column: 1
+  end_location:
+    row: 12
+    column: 17
+  fix: ~
+- kind:
+    UnnecessaryDoubleCastOrProcess:
+      - sorted
+      - sorted
+  location:
+    row: 13
+    column: 1
+  end_location:
+    row: 13
+    column: 18
+  fix: ~
+- kind:
+    UnnecessaryDoubleCastOrProcess:
+      - reversed
+      - sorted
+  location:
+    row: 14
+    column: 1
+  end_location:
+    row: 14
+    column: 20
+  fix: ~
+