Bugfix: Clamp Note.noteNumber to MIDI range (0-127) to prevent crashes (#57)

* Bugfix: Clamp noteNumber to MIDI range (0-127) to prevent crashes

- Add early bounds checking for octave values outside -2 to 8 range. Fixes infinite loop for octaves below -2
- Add final bounds checking to ensure note values are within MIDI range. Prevents crash on cast to Int8 for values > 127
- Add test coverage

* Fix coding style violations

Author: murphlab

Sources/Tonic/Note.swift

@@ -82,19 +82,31 @@ public struct Note: Sendable, Equatable, Hashable, Codable {
 
     /// MIDI Note 0-127 starting at C
     public var noteNumber: Int8 {
-        let octaveBounds = ((octave + 2) * 12) ... ((octave + 3) * 12)
-        var note = Int(noteClass.letter.baseNote) + Int(noteClass.accidental.rawValue)
-        if noteClass.letter == .B && noteClass.accidental.rawValue > 0 {
-            note -= 12
-        }
-        if noteClass.letter == .C && noteClass.accidental.rawValue < 0 {
-            note += 12
-        }
-        while !octaveBounds.contains(note) {
-            note += 12
-        }
-        return Int8(note)
-    }
+         if octave < -2 {
+             return 0
+         }
+         if octave > 8 {
+             return 127
+         }
+         let octaveBounds = ((octave + 2) * 12) ... ((octave + 3) * 12)
+         var note = Int(noteClass.letter.baseNote) + Int(noteClass.accidental.rawValue)
+         if noteClass.letter == .B && noteClass.accidental.rawValue > 0 {
+             note -= 12
+         }
+         if noteClass.letter == .C && noteClass.accidental.rawValue < 0 {
+             note += 12
+         }
+         while !octaveBounds.contains(note) {
+             note += 12
+         }
+         if note < 0 {
+             return 0
+         }
+         if note > 127 {
+             return 127
+         }
+         return Int8(note)
+     }
 
     /// The pitch for the note
     public var pitch: Pitch {

Tests/TonicTests/NoteTests.swift

@@ -162,4 +162,21 @@ final class NoteTests: XCTestCase {
         let empty = NoteSet()
         XCTAssertNil(empty.first)
     }
+
+    func testClampNoteBounds() {
+       let bMinus3 = Note(.B, octave: -3)
+       XCTAssertEqual(bMinus3.noteNumber, 0)
+       
+       let cFlatMinus3 = Note(.C, accidental: .flat, octave: -3)
+       XCTAssertEqual(cFlatMinus3.noteNumber, 0)
+       
+       let a8 = Note(.A, octave: 8)
+       XCTAssertEqual(a8.noteNumber, 127)
+       
+       let gSharp8 = Note(.G, accidental: .sharp, octave: 8)
+       XCTAssertEqual(gSharp8.noteNumber, 127)
+       
+       let c9 = Note(.C, octave: 9)
+       XCTAssertEqual(c9.noteNumber, 127)
+   }
 }