Improve Ukulele fingerings

src/fingerings.js

@@ -137,15 +137,19 @@ function findFingerings(notes, optionalNotes = [], bass = notes[0], tuning = 'E-
 
   let fingerings = [];
   let positions = findPositions(notes, tuning);
+  let isTuningAscending = JSON.stringify(tuning) === JSON.stringify(originalTuning);
 
   const requiredNotes = notes.slice().filter(n => !optionalNotes.includes(n));
   let maxBassStringIndex = tuning.length - requiredNotes.length;
   if (!requiredNotes.includes(bass)) {
     maxBassStringIndex--;
   }
-  let bassPositions = positions
-    .filter(p => areNotesEqual(p.note, bass))
-    .filter(p => p.stringIndex <= maxBassStringIndex);
+  let bassPositions = positions;
+  if (isTuningAscending) {
+    bassPositions = positions
+      .filter(p => areNotesEqual(p.note, bass))
+      .filter(p => p.stringIndex <= maxBassStringIndex);
+  }
 
   for (let i = 0; i < bassPositions.length; i++) {
     let bassPosition = bassPositions[i];
@@ -162,8 +166,11 @@ function findFingerings(notes, optionalNotes = [], bass = notes[0], tuning = 'E-
           return position.fret === 0 ||
             nonZeroFrets.every(fret => Math.abs(position.fret - fret) <= MAX_FRET_DISTANCE);
         });
-        const sensiblePositions = reachablePositions.filter(p =>
-          tonal.distance(bassPosition.note, p.note)[0] !== '-');
+        let sensiblePositions = reachablePositions;
+        if (isTuningAscending) {
+          sensiblePositions = reachablePositions.filter(p =>
+            tonal.distance(bassPosition.note, p.note)[0] !== '-');
+        }
         if (sensiblePositions.length) {
           return sensiblePositions.map(position => [...fingering, position]);
         }
@@ -233,12 +240,14 @@ function findFingerings(notes, optionalNotes = [], bass = notes[0], tuning = 'E-
       return 0
         || notLessThanFourStrings
         || lessMutedStringsInBetween
+        || (isTuningAscending ? 0 : lowerMaxFret)
+        || (isTuningAscending ? 0 : easier)
         || lessRepeatingNotes
         || easierThan14
         || lowerBassFret
         || easierThan12
-        || lowerMaxFret
-        || easier
+        || (isTuningAscending ? lowerMaxFret : 0)
+        || (isTuningAscending ? easier : 0)
         || 0;
     });
   return fingerings;

src/fingerings.test.js

@@ -104,68 +104,84 @@ describe('fingerings', () => {
     expect(matching).toBeTruthy();
   });
 
-  const pos = (s, i) => {
+  const pos = (s, i, tuning = 'E-A-D-G-B-E') => {
     const c = findChord(s);
     const { notes, optionalNotes } = c;
-    return findFingerings(notes, optionalNotes)[i].positionString;
+    return findFingerings(notes, optionalNotes, notes[0], tuning)[i].positionString;
   };
   it('sort C fingerings correctly', () => {
     expect(pos('C', 0)).toBe('x32010');
+    expect(pos('C', 0, 'G4-C4-E4-A4')).toBe('0003');
   });
   it('sort Cm fingerings correctly', () => {
     expect(pos('Cm', 0)).toBe('x35543');
+    expect(pos('Cm', 0, 'G4-C4-E4-A4')).toBe('0333');
   });
   it('sort C# fingerings correctly', () => {
     expect(pos('C#', 0)).toBe('x46664');
+    expect(pos('C#', 0, 'G4-C4-E4-A4')).toBe('1114');
   });
 
   it('sort D fingerings correctly', () => {
     expect(pos('D', 0)).toBe('xx0232');
+    expect(pos('D', 0, 'G4-C4-E4-A4')).toBe('2220');
   });
   it('sort Dm fingerings correctly', () => {
     expect(pos('Dm', 0)).toBe('xx0231');
+    expect(pos('Dm', 0, 'G4-C4-E4-A4')).toBe('2210');
   });
 
   it('sort E fingerings correctly', () => {
     expect(pos('E', 0)).toBe('022100');
+    expect(pos('E', 0, 'G4-C4-E4-A4')).toBe('4442');
   });
   it('sort Em fingerings correctly', () => {
     expect(pos('Em', 0)).toBe('022000');
+    expect(pos('Em', 0, 'G4-C4-E4-A4')).toBe('0432');
   });
 
   it('sort F fingerings correctly', () => {
     expect(pos('F', 0)).toBe('133211');
     expect(pos('F', 1)).toBe('xx3211');
+    expect(pos('F', 0, 'G4-C4-E4-A4')).toBe('2010');
   });
   it('sort Fm fingerings correctly', () => {
     expect(pos('Fm', 0)).toBe('133111');
+    expect(pos('Fm', 0, 'G4-C4-E4-A4')).toBe('1013');
   });
 
   it('sort G fingerings correctly', () => {
     expect(pos('G', 0)).toBe('320003');
     expect(pos('G', 1)).toBe('320033');
+    expect(pos('G', 0, 'G4-C4-E4-A4')).toBe('0232');
   });
   it('sort Gm fingerings correctly', () => {
     expect(pos('Gm', 0)).toBe('355333');
+    expect(pos('Gm', 0, 'G4-C4-E4-A4')).toBe('0231');
   });
 
   it('sort A fingerings correctly', () => {
     expect(pos('A', 0)).toBe('x02220');
     // expect(pos('A', 1)).toBe('577655');
+    expect(pos('A', 0, 'G4-C4-E4-A4')).toBe('2100');
   });
   it('sort Am fingerings correctly', () => {
     expect(pos('Am', 0)).toBe('x02210');
+    expect(pos('Am', 0, 'G4-C4-E4-A4')).toBe('2000');
   });
 
   it('sort B fingerings correctly', () => {
     expect(pos('B', 0)).toBe('x24442');
     expect(pos('B', 1)).toBe('799877');
+    expect(pos('B', 0, 'G4-C4-E4-A4')).toBe('4322');
   });
 
   it('sort B7 fingerings correctly', () => {
     expect(pos('B7', 0)).toBe('x21202');
+    expect(pos('B7', 0, 'G4-C4-E4-A4')).toBe('2322');
   });
   it('sort Bm fingerings correctly', () => {
     expect(pos('Bm', 0)).toBe('x24432');
+    expect(pos('Bm', 0, 'G4-C4-E4-A4')).toBe('4222');
   });
 });