[pyupgrade] Detect literals with unary operators (UP018) (#10060)

Fix #10029.

crates/ruff_linter/resources/test/fixtures/pyupgrade/UP018.py

@@ -33,7 +33,7 @@ bool(b"")
 bool(1.0)
 int().denominator
 
-# These become string or byte literals
+# These become literals
 str()
 str("foo")
 str("""
@@ -53,3 +53,9 @@ bool(False)
 
 # These become a literal but retain parentheses
 int(1).denominator
+
+# These too are literals in spirit
+int(+1)
+int(-1)
+float(+1.0)
+float(-1.0)

crates/ruff_linter/src/rules/pyupgrade/rules/native_literals.rs

@@ -3,7 +3,7 @@ use std::str::FromStr;
 
 use ruff_diagnostics::{AlwaysFixableViolation, Diagnostic, Edit, Fix};
 use ruff_macros::{derive_message_formats, violation};
-use ruff_python_ast::{self as ast, Expr, LiteralExpressionRef};
+use ruff_python_ast::{self as ast, Expr, LiteralExpressionRef, UnaryOp};
 use ruff_text_size::{Ranged, TextRange};
 
 use crate::checkers::ast::Checker;
@@ -198,15 +198,31 @@ pub(crate) fn native_literals(
             checker.diagnostics.push(diagnostic);
         }
         Some(arg) => {
-            let Some(literal_expr) = arg.as_literal_expr() else {
+            let literal_expr = if let Some(literal_expr) = arg.as_literal_expr() {
+                // Skip implicit concatenated strings.
+                if literal_expr.is_implicit_concatenated() {
+                    return;
+                }
+                literal_expr
+            } else if let Expr::UnaryOp(ast::ExprUnaryOp {
+                op: UnaryOp::UAdd | UnaryOp::USub,
+                operand,
+                ..
+            }) = arg
+            {
+                if let Some(literal_expr) = operand
+                    .as_literal_expr()
+                    .filter(|expr| matches!(expr, LiteralExpressionRef::NumberLiteral(_)))
+                {
+                    literal_expr
+                } else {
+                    // Only allow unary operators for numbers.
+                    return;
+                }
+            } else {
                 return;
             };
 
-            // Skip implicit string concatenations.
-            if literal_expr.is_implicit_concatenated() {
-                return;
-            }
-
             let Ok(arg_literal_type) = LiteralType::try_from(literal_expr) else {
                 return;
             };
@@ -221,14 +237,8 @@ pub(crate) fn native_literals(
             // Ex) `(7).denominator` is valid but `7.denominator` is not
             // Note that floats do not have this problem
             // Ex) `(1.0).real` is valid and `1.0.real` is too
-            let content = match (parent_expr, arg) {
-                (
-                    Some(Expr::Attribute(_)),
-                    Expr::NumberLiteral(ast::ExprNumberLiteral {
-                        value: ast::Number::Int(_),
-                        ..
-                    }),
-                ) => format!("({arg_code})"),
+            let content = match (parent_expr, literal_type) {
+                (Some(Expr::Attribute(_)), LiteralType::Int) => format!("({arg_code})"),
                 _ => arg_code.to_string(),
             };
 

crates/ruff_linter/src/rules/pyupgrade/snapshots/ruff_linter__rules__pyupgrade__tests__UP018.py.snap

@@ -3,7 +3,7 @@ source: crates/ruff_linter/src/rules/pyupgrade/mod.rs
 ---
 UP018.py:37:1: UP018 [*] Unnecessary `str` call (rewrite as a literal)
    |
-36 | # These become string or byte literals
+36 | # These become literals
 37 | str()
    | ^^^^^ UP018
 38 | str("foo")
@@ -14,7 +14,7 @@ UP018.py:37:1: UP018 [*] Unnecessary `str` call (rewrite as a literal)
 ℹ Safe fix
 34 34 | int().denominator
 35 35 | 
-36 36 | # These become string or byte literals
+36 36 | # These become literals
 37    |-str()
    37 |+""
 38 38 | str("foo")
@@ -23,7 +23,7 @@ UP018.py:37:1: UP018 [*] Unnecessary `str` call (rewrite as a literal)
 
 UP018.py:38:1: UP018 [*] Unnecessary `str` call (rewrite as a literal)
    |
-36 | # These become string or byte literals
+36 | # These become literals
 37 | str()
 38 | str("foo")
    | ^^^^^^^^^^ UP018
@@ -34,7 +34,7 @@ UP018.py:38:1: UP018 [*] Unnecessary `str` call (rewrite as a literal)
 
 ℹ Safe fix
 35 35 | 
-36 36 | # These become string or byte literals
+36 36 | # These become literals
 37 37 | str()
 38    |-str("foo")
    38 |+"foo"
@@ -55,7 +55,7 @@ UP018.py:39:1: UP018 [*] Unnecessary `str` call (rewrite as a literal)
    = help: Replace with string literal
 
 ℹ Safe fix
-36 36 | # These become string or byte literals
+36 36 | # These become literals
 37 37 | str()
 38 38 | str("foo")
 39    |-str("""
@@ -304,6 +304,8 @@ UP018.py:55:1: UP018 [*] Unnecessary `int` call (rewrite as a literal)
 54 | # These become a literal but retain parentheses
 55 | int(1).denominator
    | ^^^^^^ UP018
+56 | 
+57 | # These too are literals in spirit
    |
    = help: Replace with integer literal
 
@@ -313,5 +315,82 @@ UP018.py:55:1: UP018 [*] Unnecessary `int` call (rewrite as a literal)
 54 54 | # These become a literal but retain parentheses
 55    |-int(1).denominator
    55 |+(1).denominator
+56 56 | 
+57 57 | # These too are literals in spirit
+58 58 | int(+1)
+
+UP018.py:58:1: UP018 [*] Unnecessary `int` call (rewrite as a literal)
+   |
+57 | # These too are literals in spirit
+58 | int(+1)
+   | ^^^^^^^ UP018
+59 | int(-1)
+60 | float(+1.0)
+   |
+   = help: Replace with integer literal
+
+ℹ Safe fix
+55 55 | int(1).denominator
+56 56 | 
+57 57 | # These too are literals in spirit
+58    |-int(+1)
+   58 |++1
+59 59 | int(-1)
+60 60 | float(+1.0)
+61 61 | float(-1.0)
+
+UP018.py:59:1: UP018 [*] Unnecessary `int` call (rewrite as a literal)
+   |
+57 | # These too are literals in spirit
+58 | int(+1)
+59 | int(-1)
+   | ^^^^^^^ UP018
+60 | float(+1.0)
+61 | float(-1.0)
+   |
+   = help: Replace with integer literal
+
+ℹ Safe fix
+56 56 | 
+57 57 | # These too are literals in spirit
+58 58 | int(+1)
+59    |-int(-1)
+   59 |+-1
+60 60 | float(+1.0)
+61 61 | float(-1.0)
+
+UP018.py:60:1: UP018 [*] Unnecessary `float` call (rewrite as a literal)
+   |
+58 | int(+1)
+59 | int(-1)
+60 | float(+1.0)
+   | ^^^^^^^^^^^ UP018
+61 | float(-1.0)
+   |
+   = help: Replace with float literal
+
+ℹ Safe fix
+57 57 | # These too are literals in spirit
+58 58 | int(+1)
+59 59 | int(-1)
+60    |-float(+1.0)
+   60 |++1.0
+61 61 | float(-1.0)
+
+UP018.py:61:1: UP018 [*] Unnecessary `float` call (rewrite as a literal)
+   |
+59 | int(-1)
+60 | float(+1.0)
+61 | float(-1.0)
+   | ^^^^^^^^^^^ UP018
+   |
+   = help: Replace with float literal
+
+ℹ Safe fix
+58 58 | int(+1)
+59 59 | int(-1)
+60 60 | float(+1.0)
+61    |-float(-1.0)
+   61 |+-1.0