[refurb] Preserve digit separators in Decimal constructor (FURB157)

crates/ruff_linter/resources/test/fixtures/refurb/FURB157.py

@@ -69,3 +69,19 @@
 Decimal(float("\x20\N{character tabulation}\N{hyphen-minus}nan"))
 Decimal(float("   -" "nan"))
 Decimal(float("-nAn"))
+
+# Test cases for digit separators (safe fixes)
+# https://github.com/astral-sh/ruff/issues/20572
+Decimal("15_000_000")  # Safe fix: normalizes separators, becomes Decimal(15_000_000)
+Decimal("1_234_567")   # Safe fix: normalizes separators, becomes Decimal(1_234_567)
+Decimal("-5_000")      # Safe fix: normalizes separators, becomes Decimal(-5_000)
+Decimal("+9_999")      # Safe fix: normalizes separators, becomes Decimal(+9_999)
+
+# Test cases for non-thousands separators
+Decimal("12_34_56_78")  # Safe fix: preserves non-thousands separators
+Decimal("1234_5678")    # Safe fix: preserves non-thousands separators
+
+# Separators _and_ leading zeros
+Decimal("0001_2345")
+Decimal("000_1_2345")
+Decimal("000_000")

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

@@ -1,5 +1,6 @@
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 
+use itertools::Itertools;
 use ruff_python_ast::{self as ast, Expr};
 use ruff_python_trivia::PythonWhitespace;
 use ruff_text_size::Ranged;
@@ -90,18 +91,20 @@ pub(crate) fn verbose_decimal_constructor(checker: &Checker, call: &ast::ExprCal
             // using this regex:
             // https://github.com/python/cpython/blob/ac556a2ad1213b8bb81372fe6fb762f5fcb076de/Lib/_pydecimal.py#L6060-L6077
             // _after_ trimming whitespace from the string and removing all occurrences of "_".
-            let mut trimmed = Cow::from(str_literal.to_str().trim_whitespace());
-            if memchr::memchr(b'_', trimmed.as_bytes()).is_some() {
-                trimmed = Cow::from(trimmed.replace('_', ""));
-            }
+            let original_str = str_literal.to_str().trim_whitespace();
             // Extract the unary sign, if any.
-            let (unary, rest) = if let Some(trimmed) = trimmed.strip_prefix('+') {
-                ("+", Cow::from(trimmed))
-            } else if let Some(trimmed) = trimmed.strip_prefix('-') {
-                ("-", Cow::from(trimmed))
+            let (unary, original_str) = if let Some(trimmed) = original_str.strip_prefix('+') {
+                ("+", trimmed)
+            } else if let Some(trimmed) = original_str.strip_prefix('-') {
+                ("-", trimmed)
             } else {
-                ("", trimmed)
+                ("", original_str)
             };
+            let mut rest = Cow::from(original_str);
+            let has_digit_separators = memchr::memchr(b'_', rest.as_bytes()).is_some();
+            if has_digit_separators {
+                rest = Cow::from(rest.replace('_', ""));
+            }
 
             // Early return if we now have an empty string
             // or a very long string:
@@ -117,6 +120,13 @@ pub(crate) fn verbose_decimal_constructor(checker: &Checker, call: &ast::ExprCal
                 return;
             }
 
+            // If the original string had digit separators, normalize them
+            let rest = if has_digit_separators {
+                Cow::from(normalize_digit_separators(original_str))
+            } else {
+                Cow::from(rest)
+            };
+
             // If all the characters are zeros, then the value is zero.
             let rest = match (unary, rest.is_empty()) {
                 // `Decimal("-0")` is not the same as `Decimal("0")`
@@ -125,10 +135,11 @@ pub(crate) fn verbose_decimal_constructor(checker: &Checker, call: &ast::ExprCal
                     return;
                 }
                 (_, true) => "0",
-                _ => rest,
+                _ => &rest,
             };
 
             let replacement = format!("{unary}{rest}");
+
             let mut diagnostic = checker.report_diagnostic(
                 VerboseDecimalConstructor {
                     replacement: replacement.clone(),
@@ -185,6 +196,22 @@ pub(crate) fn verbose_decimal_constructor(checker: &Checker, call: &ast::ExprCal
     }
 }
 
+/// Normalizes digit separators in a numeric string by:
+/// - Stripping leading and trailing underscores
+/// - Collapsing medial underscore sequences to single underscores
+fn normalize_digit_separators(original_str: &str) -> String {
+    // Strip leading and trailing underscores
+    let trimmed = original_str
+        .trim_start_matches(['_', '0'])
+        .trim_end_matches('_');
+
+    // Collapse medial underscore sequences to single underscores
+    trimmed
+        .chars()
+        .dedup_by(|a, b| *a == '_' && a == b)
+        .collect()
+}
+
 // ```console
 // $ python
 // >>> import sys

crates/ruff_linter/src/rules/refurb/snapshots/ruff_linter__rules__refurb__tests__FURB157_FURB157.py.snap

@@ -167,12 +167,12 @@ FURB157 [*] Verbose expression in `Decimal` constructor
    |         ^^^^^^^
 24 | Decimal("__1____000") 
    |
-help: Replace with `1000`
+help: Replace with `1_000`
 20 | # See https://github.com/astral-sh/ruff/issues/13807
 21 | 
 22 | # Errors
    - Decimal("1_000")
-23 + Decimal(1000)
+23 + Decimal(1_000)
 24 | Decimal("__1____000") 
 25 | 
 26 | # Ok
@@ -187,12 +187,12 @@ FURB157 [*] Verbose expression in `Decimal` constructor
 25 |
 26 | # Ok
    |
-help: Replace with `1000`
+help: Replace with `1_000`
 21 | 
 22 | # Errors
 23 | Decimal("1_000")
    - Decimal("__1____000") 
-24 + Decimal(1000) 
+24 + Decimal(1_000) 
 25 | 
 26 | # Ok
 27 | Decimal("2e-4")
@@ -494,6 +494,7 @@ help: Replace with `"nan"`
 69 + Decimal("nan")
 70 | Decimal(float("   -" "nan"))
 71 | Decimal(float("-nAn"))
+72 | 
 
 FURB157 [*] Verbose expression in `Decimal` constructor
   --> FURB157.py:70:9
@@ -511,6 +512,8 @@ help: Replace with `"nan"`
    - Decimal(float("   -" "nan"))
 70 + Decimal("nan")
 71 | Decimal(float("-nAn"))
+72 | 
+73 | # Test cases for digit separators (safe fixes)
 
 FURB157 [*] Verbose expression in `Decimal` constructor
   --> FURB157.py:71:9
@@ -519,10 +522,182 @@ FURB157 [*] Verbose expression in `Decimal` constructor
 70 | Decimal(float("   -" "nan"))
 71 | Decimal(float("-nAn"))
    |         ^^^^^^^^^^^^^
+72 |
+73 | # Test cases for digit separators (safe fixes)
    |
 help: Replace with `"nan"`
 68 | Decimal(float("\N{space}\N{hyPHen-MINus}nan"))
 69 | Decimal(float("\x20\N{character tabulation}\N{hyphen-minus}nan"))
 70 | Decimal(float("   -" "nan"))
    - Decimal(float("-nAn"))
 71 + Decimal("nan")
+72 | 
+73 | # Test cases for digit separators (safe fixes)
+74 | # https://github.com/astral-sh/ruff/issues/20572
+
+FURB157 [*] Verbose expression in `Decimal` constructor
+  --> FURB157.py:75:9
+   |
+73 | # Test cases for digit separators (safe fixes)
+74 | # https://github.com/astral-sh/ruff/issues/20572
+75 | Decimal("15_000_000")  # Safe fix: normalizes separators, becomes Decimal(15_000_000)
+   |         ^^^^^^^^^^^^
+76 | Decimal("1_234_567")   # Safe fix: normalizes separators, becomes Decimal(1_234_567)
+77 | Decimal("-5_000")      # Safe fix: normalizes separators, becomes Decimal(-5_000)
+   |
+help: Replace with `15_000_000`
+72 | 
+73 | # Test cases for digit separators (safe fixes)
+74 | # https://github.com/astral-sh/ruff/issues/20572
+   - Decimal("15_000_000")  # Safe fix: normalizes separators, becomes Decimal(15_000_000)
+75 + Decimal(15_000_000)  # Safe fix: normalizes separators, becomes Decimal(15_000_000)
+76 | Decimal("1_234_567")   # Safe fix: normalizes separators, becomes Decimal(1_234_567)
+77 | Decimal("-5_000")      # Safe fix: normalizes separators, becomes Decimal(-5_000)
+78 | Decimal("+9_999")      # Safe fix: normalizes separators, becomes Decimal(+9_999)
+
+FURB157 [*] Verbose expression in `Decimal` constructor
+  --> FURB157.py:76:9
+   |
+74 | # https://github.com/astral-sh/ruff/issues/20572
+75 | Decimal("15_000_000")  # Safe fix: normalizes separators, becomes Decimal(15_000_000)
+76 | Decimal("1_234_567")   # Safe fix: normalizes separators, becomes Decimal(1_234_567)
+   |         ^^^^^^^^^^^
+77 | Decimal("-5_000")      # Safe fix: normalizes separators, becomes Decimal(-5_000)
+78 | Decimal("+9_999")      # Safe fix: normalizes separators, becomes Decimal(+9_999)
+   |
+help: Replace with `1_234_567`
+73 | # Test cases for digit separators (safe fixes)
+74 | # https://github.com/astral-sh/ruff/issues/20572
+75 | Decimal("15_000_000")  # Safe fix: normalizes separators, becomes Decimal(15_000_000)
+   - Decimal("1_234_567")   # Safe fix: normalizes separators, becomes Decimal(1_234_567)
+76 + Decimal(1_234_567)   # Safe fix: normalizes separators, becomes Decimal(1_234_567)
+77 | Decimal("-5_000")      # Safe fix: normalizes separators, becomes Decimal(-5_000)
+78 | Decimal("+9_999")      # Safe fix: normalizes separators, becomes Decimal(+9_999)
+79 | 
+
+FURB157 [*] Verbose expression in `Decimal` constructor
+  --> FURB157.py:77:9
+   |
+75 | Decimal("15_000_000")  # Safe fix: normalizes separators, becomes Decimal(15_000_000)
+76 | Decimal("1_234_567")   # Safe fix: normalizes separators, becomes Decimal(1_234_567)
+77 | Decimal("-5_000")      # Safe fix: normalizes separators, becomes Decimal(-5_000)
+   |         ^^^^^^^^
+78 | Decimal("+9_999")      # Safe fix: normalizes separators, becomes Decimal(+9_999)
+   |
+help: Replace with `-5_000`
+74 | # https://github.com/astral-sh/ruff/issues/20572
+75 | Decimal("15_000_000")  # Safe fix: normalizes separators, becomes Decimal(15_000_000)
+76 | Decimal("1_234_567")   # Safe fix: normalizes separators, becomes Decimal(1_234_567)
+   - Decimal("-5_000")      # Safe fix: normalizes separators, becomes Decimal(-5_000)
+77 + Decimal(-5_000)      # Safe fix: normalizes separators, becomes Decimal(-5_000)
+78 | Decimal("+9_999")      # Safe fix: normalizes separators, becomes Decimal(+9_999)
+79 | 
+80 | # Test cases for non-thousands separators
+
+FURB157 [*] Verbose expression in `Decimal` constructor
+  --> FURB157.py:78:9
+   |
+76 | Decimal("1_234_567")   # Safe fix: normalizes separators, becomes Decimal(1_234_567)
+77 | Decimal("-5_000")      # Safe fix: normalizes separators, becomes Decimal(-5_000)
+78 | Decimal("+9_999")      # Safe fix: normalizes separators, becomes Decimal(+9_999)
+   |         ^^^^^^^^
+79 |
+80 | # Test cases for non-thousands separators
+   |
+help: Replace with `+9_999`
+75 | Decimal("15_000_000")  # Safe fix: normalizes separators, becomes Decimal(15_000_000)
+76 | Decimal("1_234_567")   # Safe fix: normalizes separators, becomes Decimal(1_234_567)
+77 | Decimal("-5_000")      # Safe fix: normalizes separators, becomes Decimal(-5_000)
+   - Decimal("+9_999")      # Safe fix: normalizes separators, becomes Decimal(+9_999)
+78 + Decimal(+9_999)      # Safe fix: normalizes separators, becomes Decimal(+9_999)
+79 | 
+80 | # Test cases for non-thousands separators
+81 | Decimal("12_34_56_78")  # Safe fix: preserves non-thousands separators
+
+FURB157 [*] Verbose expression in `Decimal` constructor
+  --> FURB157.py:81:9
+   |
+80 | # Test cases for non-thousands separators
+81 | Decimal("12_34_56_78")  # Safe fix: preserves non-thousands separators
+   |         ^^^^^^^^^^^^^
+82 | Decimal("1234_5678")    # Safe fix: preserves non-thousands separators
+   |
+help: Replace with `12_34_56_78`
+78 | Decimal("+9_999")      # Safe fix: normalizes separators, becomes Decimal(+9_999)
+79 | 
+80 | # Test cases for non-thousands separators
+   - Decimal("12_34_56_78")  # Safe fix: preserves non-thousands separators
+81 + Decimal(12_34_56_78)  # Safe fix: preserves non-thousands separators
+82 | Decimal("1234_5678")    # Safe fix: preserves non-thousands separators
+83 | 
+84 | # Separators _and_ leading zeros
+
+FURB157 [*] Verbose expression in `Decimal` constructor
+  --> FURB157.py:82:9
+   |
+80 | # Test cases for non-thousands separators
+81 | Decimal("12_34_56_78")  # Safe fix: preserves non-thousands separators
+82 | Decimal("1234_5678")    # Safe fix: preserves non-thousands separators
+   |         ^^^^^^^^^^^
+83 |
+84 | # Separators _and_ leading zeros
+   |
+help: Replace with `1234_5678`
+79 | 
+80 | # Test cases for non-thousands separators
+81 | Decimal("12_34_56_78")  # Safe fix: preserves non-thousands separators
+   - Decimal("1234_5678")    # Safe fix: preserves non-thousands separators
+82 + Decimal(1234_5678)    # Safe fix: preserves non-thousands separators
+83 | 
+84 | # Separators _and_ leading zeros
+85 | Decimal("0001_2345")
+
+FURB157 [*] Verbose expression in `Decimal` constructor
+  --> FURB157.py:85:9
+   |
+84 | # Separators _and_ leading zeros
+85 | Decimal("0001_2345")
+   |         ^^^^^^^^^^^
+86 | Decimal("000_1_2345")
+87 | Decimal("000_000")
+   |
+help: Replace with `1_2345`
+82 | Decimal("1234_5678")    # Safe fix: preserves non-thousands separators
+83 | 
+84 | # Separators _and_ leading zeros
+   - Decimal("0001_2345")
+85 + Decimal(1_2345)
+86 | Decimal("000_1_2345")
+87 | Decimal("000_000")
+
+FURB157 [*] Verbose expression in `Decimal` constructor
+  --> FURB157.py:86:9
+   |
+84 | # Separators _and_ leading zeros
+85 | Decimal("0001_2345")
+86 | Decimal("000_1_2345")
+   |         ^^^^^^^^^^^^
+87 | Decimal("000_000")
+   |
+help: Replace with `1_2345`
+83 | 
+84 | # Separators _and_ leading zeros
+85 | Decimal("0001_2345")
+   - Decimal("000_1_2345")
+86 + Decimal(1_2345)
+87 | Decimal("000_000")
+
+FURB157 [*] Verbose expression in `Decimal` constructor
+  --> FURB157.py:87:9
+   |
+85 | Decimal("0001_2345")
+86 | Decimal("000_1_2345")
+87 | Decimal("000_000")
+   |         ^^^^^^^^^
+   |
+help: Replace with `0`
+84 | # Separators _and_ leading zeros
+85 | Decimal("0001_2345")
+86 | Decimal("000_1_2345")
+   - Decimal("000_000")
+87 + Decimal(0)