test tonal methods + move mod to util

repl/src/evaluate.ts

@@ -2,7 +2,7 @@ import * as strudel from '../../strudel.mjs';
 import './tone';
 import './midi';
 import './voicings';
-import './tonal';
+import './tonal.mjs';
 import shapeshifter from './shapeshifter';
 import { minify } from './parse';
 import * as Tone from 'tone';

repl/src/tonal.mjs

@@ -1,37 +1,24 @@
 import { Note, Interval, Scale } from '@tonaljs/tonal';
 import { Pattern as _Pattern } from '../../strudel.mjs';
+import { mod, tokenizeNote } from '../../util.mjs';
 
-const Pattern = _Pattern as any;
+const Pattern = _Pattern; // as any;
 
-// modulo that works with negative numbers e.g. mod(-1, 3) = 2
-const mod = (n: number, m: number): number => (n < 0 ? mod(n + m, m) : n % m);
-
-export function intervalDirection(from, to, direction = 1) {
-  const sign = Math.sign(direction);
-  const interval = sign < 0 ? Interval.distance(to, from) : Interval.distance(from, to);
-  return (sign < 0 ? '-' : '') + interval;
-}
-
-// transpose note inside scale by offset steps
-function scaleTranspose(scale: string, offset: number, note: string) {
+export function scaleOffset(scale, offset, index = 0) {
   let [tonic, scaleName] = Scale.tokenize(scale);
+  const [pc, acc, oct = 3] = tokenizeNote(tonic);
   let { notes } = Scale.get(`${tonic} ${scaleName}`);
   notes = notes.map((note) => Note.get(note).pc); // use only pc!
   offset = Number(offset);
   if (isNaN(offset)) {
     throw new Error(`scale offset "${offset}" not a number`);
   }
-  const { pc: fromPc, oct = 3 } = Note.get(note);
-  const noteIndex = notes.indexOf(fromPc);
-  if (noteIndex === -1) {
-    throw new Error(`note "${note}" is not in scale "${scale}"`);
-  }
-  let i = noteIndex,
+  let i = index,
     o = oct,
-    n = fromPc;
+    n = notes[0];
   const direction = Math.sign(offset);
   // TODO: find way to do this smarter
-  while (Math.abs(i - noteIndex) < Math.abs(offset)) {
+  while (Math.abs(i) < Math.abs(offset)) {
     i += direction;
     const index = mod(i, notes.length);
     if (direction < 0 && n === 'C') {
@@ -44,11 +31,25 @@ function scaleTranspose(scale: string, offset: number, note: string) {
   }
   return n + o;
 }
+// transpose note inside scale by offset steps
+// function scaleTranspose(scale: string, offset: number, note: string) {
+export function scaleTranspose(scale, offset, note) {
+  let [tonic, scaleName] = Scale.tokenize(scale);
+  const { pc: fromPc } = Note.get(note);
+  let { notes } = Scale.get(`${tonic} ${scaleName}`);
+  const scalePcs = notes.map((n) => Note.get(n).pc);
+  const noteIndex = scalePcs.indexOf(fromPc);
+  if (noteIndex === -1) {
+    throw new Error(`note "${fromPc}" is not in scale "${scale}". Use one of ${scalePcs.join('|')}`);
+  }
+  return scaleOffset(scale, offset, noteIndex);
+}
 
-Pattern.prototype._transpose = function (intervalOrSemitones: string | number) {
+// Pattern.prototype._transpose = function (intervalOrSemitones: string | number) {
+Pattern.prototype._transpose = function (intervalOrSemitones) {
   return this._withEvent((event) => {
     const interval = !isNaN(Number(intervalOrSemitones))
-      ? Interval.fromSemitones(intervalOrSemitones as number)
+      ? Interval.fromSemitones(intervalOrSemitones /*  as number */)
       : String(intervalOrSemitones);
     if (typeof event.value === 'number') {
       const semitones = typeof interval === 'string' ? Interval.semitones(interval) || 0 : interval;
@@ -64,7 +65,7 @@ Pattern.prototype._transpose = function (intervalOrSemitones: string | number) {
 // e.g. `stack(c3).superimpose(transpose(slowcat(7, 5)))` or
 // or even `stack(c3).superimpose(transpose.slowcat(7, 5))` or
 
-Pattern.prototype._scaleTranspose = function (offset: number | string) {
+Pattern.prototype._scaleTranspose = function (offset /* : number | string */) {
   return this._withEvent((event) => {
     if (!event.context.scale) {
       throw new Error('can only use scaleTranspose after .scale');
@@ -75,7 +76,7 @@ Pattern.prototype._scaleTranspose = function (offset: number | string) {
     return event.withValue(() => scaleTranspose(event.context.scale, Number(offset), event.value));
   });
 };
-Pattern.prototype._scale = function (scale: string) {
+Pattern.prototype._scale = function (scale /* : string */) {
   return this._withEvent((event) => {
     let note = event.value;
     const asNumber = Number(note);

test/tonal.test.mjs

@@ -0,0 +1,39 @@
+import { strict as assert } from 'assert';
+import { scaleTranspose, scaleOffset } from '../repl/src/tonal.mjs';
+
+describe('scaleOffset', () => {
+  it('should transpose positive numbers', () => {
+    const c3Minor = ['C3', 'D3', 'Eb3', 'F3', 'G3', 'Ab3', 'Bb3', 'C4', 'D4', 'Eb4', 'F4', 'G4', 'Ab4', 'Bb4'];
+    c3Minor.forEach((n, i) => {
+      assert.equal(scaleOffset('C minor', i), n);
+    });
+    const gMinor = ['G3', 'A3', 'Bb3', 'C4', 'D4', 'Eb4', 'F4', 'G4', 'A4', 'Bb4', 'C5', 'D5', 'Eb5', 'F5', 'G5'];
+    gMinor.forEach((n, i) => {
+      assert.equal(scaleOffset('G minor', i), n);
+    });
+  });
+  it('should transpose negative numbers', () => {
+    const c3MinorDown = ['C3', 'Bb2', 'Ab2', 'G2', 'F2', 'Eb2', 'D2', 'C2'];
+    c3MinorDown.forEach((n, i) => {
+      assert.equal(scaleOffset('C minor', -i), n);
+    });
+  });
+  it('should transpose scales with octave', () => {
+    const c4Minor = ['C4', 'D4', 'Eb4', 'F4', 'G4', 'Ab4', 'Bb4', 'C5', 'D5', 'Eb5', 'F5', 'G5', 'Ab5', 'Bb5'];
+    c4Minor.forEach((n, i) => {
+      assert.equal(scaleOffset('C4 minor', i), n);
+    });
+  });
+});
+
+describe('scaleTranspose', () => {
+  it('should transpose inside scale', () => {
+    scaleTranspose('C minor', 0, 'C3');
+    scaleTranspose('C minor', 1, 'D3');
+    scaleTranspose('C minor', -1, 'Bb2');
+    scaleTranspose('C minor', 8, 'C4');
+    scaleTranspose('C4 minor', 8, 'C5');
+  });
+});
+
+// TODO: test tonal Pattern methods

test/util.test.mjs

@@ -1,18 +1,18 @@
 import { strict as assert } from 'assert';
-import { isNote, tokenizeNote, toMidi } from '../util.mjs';
+import { isNote, tokenizeNote, toMidi, mod } from '../util.mjs';
 
 describe('isNote', () => {
-  it('should recognize notes without accidentals', function () {
+  it('should recognize notes without accidentals', () => {
     'C3 D3 E3 F3 G3 A3 B3 C4 D5 c5 d5 e5'.split(' ').forEach((note) => {
       assert.equal(isNote(note), true);
     });
   });
-  it('should recognize notes with accidentals', function () {
+  it('should recognize notes with accidentals', () => {
     'C#3 D##3 Eb3 Fbb3 Bb5'.split(' ').forEach((note) => {
       assert.equal(isNote(note), true);
     });
   });
-  it('should not recognize invalid notes', function () {
+  it('should not recognize invalid notes', () => {
     assert.equal(isNote('H5'), false);
     assert.equal(isNote('C'), false);
     assert.equal(isNote('X'), false);
@@ -21,32 +21,38 @@ describe('isNote', () => {
 });
 
 describe('isNote', () => {
-  it('should tokenize notes without accidentals', function () {
-    assert.deepStrictEqual(tokenizeNote('C3'), ['C', '', '3']);
-    assert.deepStrictEqual(tokenizeNote('D3'), ['D', '', '3']);
-    assert.deepStrictEqual(tokenizeNote('E3'), ['E', '', '3']);
-    assert.deepStrictEqual(tokenizeNote('F3'), ['F', '', '3']);
-    assert.deepStrictEqual(tokenizeNote('G3'), ['G', '', '3']);
-    assert.deepStrictEqual(tokenizeNote('A3'), ['A', '', '3']);
-    assert.deepStrictEqual(tokenizeNote('B3'), ['B', '', '3']);
-    assert.deepStrictEqual(tokenizeNote('C4'), ['C', '', '4']);
-    assert.deepStrictEqual(tokenizeNote('D5'), ['D', '', '5']);
+  it('should tokenize notes without accidentals', () => {
+    assert.deepStrictEqual(tokenizeNote('C3'), ['C', '', 3]);
+    assert.deepStrictEqual(tokenizeNote('D3'), ['D', '', 3]);
+    assert.deepStrictEqual(tokenizeNote('E3'), ['E', '', 3]);
+    assert.deepStrictEqual(tokenizeNote('F3'), ['F', '', 3]);
+    assert.deepStrictEqual(tokenizeNote('G3'), ['G', '', 3]);
+    assert.deepStrictEqual(tokenizeNote('A3'), ['A', '', 3]);
+    assert.deepStrictEqual(tokenizeNote('B3'), ['B', '', 3]);
+    assert.deepStrictEqual(tokenizeNote('C4'), ['C', '', 4]);
+    assert.deepStrictEqual(tokenizeNote('D5'), ['D', '', 5]);
   });
-  it('should tokenize notes with accidentals', function () {
-    assert.deepStrictEqual(tokenizeNote('C#3'), ['C', '#', '3']);
-    assert.deepStrictEqual(tokenizeNote('D##3'), ['D', '##', '3']);
-    assert.deepStrictEqual(tokenizeNote('Eb3'), ['E', 'b', '3']);
-    assert.deepStrictEqual(tokenizeNote('Fbb3'), ['F', 'bb', '3']);
-    assert.deepStrictEqual(tokenizeNote('Bb5'), ['B', 'b', '5']);
+  it('should tokenize notes with accidentals', () => {
+    assert.deepStrictEqual(tokenizeNote('C#3'), ['C', '#', 3]);
+    assert.deepStrictEqual(tokenizeNote('D##3'), ['D', '##', 3]);
+    assert.deepStrictEqual(tokenizeNote('Eb3'), ['E', 'b', 3]);
+    assert.deepStrictEqual(tokenizeNote('Fbb3'), ['F', 'bb', 3]);
+    assert.deepStrictEqual(tokenizeNote('Bb5'), ['B', 'b', 5]);
   });
-  it('should note tokenize invalid notes', function () {
+  it('should tokenize notes without octave', () => {
+    assert.deepStrictEqual(tokenizeNote('C'), ['C', '', undefined]);
+    assert.deepStrictEqual(tokenizeNote('C#'), ['C', '#', undefined]);
+    assert.deepStrictEqual(tokenizeNote('Bb'), ['B', 'b', undefined]);
+    assert.deepStrictEqual(tokenizeNote('Bbb'), ['B', 'bb', undefined]);
+  });
+  it('should not tokenize invalid notes', () => {
     assert.deepStrictEqual(tokenizeNote('X'), []);
     assert.deepStrictEqual(tokenizeNote('asfasf'), []);
     assert.deepStrictEqual(tokenizeNote(123), []);
   });
 });
 describe('toMidi', () => {
-  it('should turn notes into midi', function () {
+  it('should turn notes into midi', () => {
     assert.equal(toMidi('A4'), 69);
     assert.equal(toMidi('C4'), 60);
     assert.equal(toMidi('Db4'), 61);
@@ -58,3 +64,22 @@ describe('toMidi', () => {
     assert.equal(toMidi('C##3'), 50);
   });
 });
+
+describe('mod', () => {
+  it('should work like regular modulo with positive numbers', () => {
+    assert.equal(mod(0, 3), 0);
+    assert.equal(mod(1, 3), 1);
+    assert.equal(mod(2, 3), 2);
+    assert.equal(mod(3, 3), 0);
+    assert.equal(mod(4, 3), 1);
+    assert.equal(mod(4, 2), 0);
+  });
+  it('should work with negative numbers', () => {
+    assert.equal(mod(-1, 3), 2);
+    assert.equal(mod(-2, 3), 1);
+    assert.equal(mod(-3, 3), 0);
+    assert.equal(mod(-4, 3), 2);
+    assert.equal(mod(-5, 3), 1);
+    assert.equal(mod(-3, 2), 1);
+  });
+});

util.mjs

@@ -1,11 +1,17 @@
+// returns true if the given string is a note
 export const isNote = (name) => /^[a-gA-G][#b]*[0-9]$/.test(name);
-export const tokenizeNote = (note) =>
-  typeof note === 'string'
-    ? note
-        .match(/^([a-gA-G])([#b]*)([0-9])?$/)
-        ?.slice(1)
-        ?.map((x) => (x === undefined ? '' : x)) || []
-    : [];
+export const tokenizeNote = (note) => {
+  if (typeof note !== 'string') {
+    return [];
+  }
+  const [pc, acc = '', oct] = note.match(/^([a-gA-G])([#b]*)([0-9])?$/)?.slice(1) || [];
+  if (!pc) {
+    return [];
+  }
+  return [pc, acc, oct ? Number(oct) : undefined];
+};
+
+// turns the given note into its midi number representation
 export const toMidi = (note) => {
   const [pc, acc, oct] = tokenizeNote(note);
   if (!pc) {
@@ -18,3 +24,7 @@ export const toMidi = (note) => {
 export const fromMidi = (n) => {
   return Math.pow(2, (n - 69) / 12) * 440;
 };
+
+// modulo that works with negative numbers e.g. mod(-1, 3) = 2
+// const mod = (n: number, m: number): number => (n < 0 ? mod(n + m, m) : n % m);
+export const mod = (n, m) => (n < 0 ? mod(n + m, m) : n % m);