Make math-constant rule more targeted

crates/ruff_linter/resources/test/fixtures/refurb/FURB152.py

@@ -5,3 +5,11 @@
 C = 6.28 * r  # FURB152
 
 e = 2.71  # FURB152
+
+r = 3.15  # OK
+
+r = 3.141  # FURB152
+
+r = 3.1415  # FURB152
+
+e = 2.7 # OK

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

@@ -53,23 +53,17 @@ pub(crate) fn math_constant(checker: &mut Checker, literal: &ast::ExprNumberLite
     let Number::Float(value) = literal.value else {
         return;
     };
-    for (real_value, constant) in [
-        (std::f64::consts::PI, "pi"),
-        (std::f64::consts::E, "e"),
-        (std::f64::consts::TAU, "tau"),
-    ] {
-        if (value - real_value).abs() < 1e-2 {
-            let mut diagnostic = Diagnostic::new(
-                MathConstant {
-                    literal: checker.locator().slice(literal).into(),
-                    constant,
-                },
-                literal.range(),
-            );
-            diagnostic.try_set_fix(|| convert_to_constant(literal, constant, checker));
-            checker.diagnostics.push(diagnostic);
-            return;
-        }
+
+    if let Some(constant) = Constant::from_value(value) {
+        let mut diagnostic = Diagnostic::new(
+            MathConstant {
+                literal: checker.locator().slice(literal).into(),
+                constant: constant.name(),
+            },
+            literal.range(),
+        );
+        diagnostic.try_set_fix(|| convert_to_constant(literal, constant.name(), checker));
+        checker.diagnostics.push(diagnostic);
     }
 }
 
@@ -88,3 +82,33 @@ fn convert_to_constant(
         [edit],
     ))
 }
+
+#[derive(Debug, Clone, Copy)]
+enum Constant {
+    Pi,
+    E,
+    Tau,
+}
+
+impl Constant {
+    #[allow(clippy::approx_constant)]
+    fn from_value(value: f64) -> Option<Self> {
+        if (3.14..3.15).contains(&value) {
+            Some(Self::Pi)
+        } else if (2.71..2.72).contains(&value) {
+            Some(Self::E)
+        } else if (6.28..6.29).contains(&value) {
+            Some(Self::Tau)
+        } else {
+            None
+        }
+    }
+
+    fn name(self) -> &'static str {
+        match self {
+            Constant::Pi => "pi",
+            Constant::E => "e",
+            Constant::Tau => "tau",
+        }
+    }
+}

crates/ruff_linter/src/rules/refurb/snapshots/ruff_linter__rules__refurb__tests__FURB152_FURB152.py.snap

@@ -43,13 +43,16 @@ FURB152.py:5:5: FURB152 [*] Replace `6.28` with `math.tau`
   6 |+C = math.tau * r  # FURB152
 6 7 | 
 7 8 | e = 2.71  # FURB152
+8 9 | 
 
 FURB152.py:7:5: FURB152 [*] Replace `2.71` with `math.e`
   |
 5 | C = 6.28 * r  # FURB152
 6 | 
 7 | e = 2.71  # FURB152
   |     ^^^^ FURB152
+8 | 
+9 | r = 3.15  # OK
   |
   = help: Use `math.e`
 
@@ -63,5 +66,59 @@ FURB152.py:7:5: FURB152 [*] Replace `2.71` with `math.e`
 6 7 | 
 7   |-e = 2.71  # FURB152
   8 |+e = math.e  # FURB152
+8 9 | 
+9 10 | r = 3.15  # OK
+10 11 | 
+
+FURB152.py:11:5: FURB152 [*] Replace `3.141` with `math.pi`
+   |
+ 9 | r = 3.15  # OK
+10 | 
+11 | r = 3.141  # FURB152
+   |     ^^^^^ FURB152
+12 | 
+13 | r = 3.1415  # FURB152
+   |
+   = help: Use `math.pi`
+
+ℹ Safe fix
+   1  |+import math
+1  2  | r = 3.1  # OK
+2  3  | 
+3  4  | A = 3.14 * r ** 2  # FURB152
+--------------------------------------------------------------------------------
+8  9  | 
+9  10 | r = 3.15  # OK
+10 11 | 
+11    |-r = 3.141  # FURB152
+   12 |+r = math.pi  # FURB152
+12 13 | 
+13 14 | r = 3.1415  # FURB152
+14 15 | 
+
+FURB152.py:13:5: FURB152 [*] Replace `3.1415` with `math.pi`
+   |
+11 | r = 3.141  # FURB152
+12 | 
+13 | r = 3.1415  # FURB152
+   |     ^^^^^^ FURB152
+14 | 
+15 | e = 2.7 # OK
+   |
+   = help: Use `math.pi`
+
+ℹ Safe fix
+   1  |+import math
+1  2  | r = 3.1  # OK
+2  3  | 
+3  4  | A = 3.14 * r ** 2  # FURB152
+--------------------------------------------------------------------------------
+10 11 | 
+11 12 | r = 3.141  # FURB152
+12 13 | 
+13    |-r = 3.1415  # FURB152
+   14 |+r = math.pi  # FURB152
+14 15 | 
+15 16 | e = 2.7 # OK