chordova-core/test/index.test.ts

import {
  describe,
  it,
  expect,
  beforeEach,
} from 'vitest';
import {
  ChordBase,
  ChordComponent,
  ChordExtensionType,
  ChordModificationType,
  constructChord,
  analyzeIntervals, getChordName,
} from '../src';

describe('constructChord', () => {
  it('works', () => {
    const chord = constructChord({ pitchClass: 0 });
    expect(chord).toEqual([0, 4, 7]);
  });
});

describe('analyzeChord', () => {
  describe('building', () => {
    let chord: number[];

    beforeEach(() => {
      chord = [];
    });

    describe('root', () => {
      beforeEach(() => {
        chord.push(0);
      });

      describe('major third', () => {
        beforeEach(() => {
          chord.push(4);
        });

        describe('perfect fifth', () => {
          beforeEach(() => {
            chord.push(7);
          });

          it('determines major chord', () => {
            expect(analyzeIntervals(chord)).toEqual({
              base: ChordBase.MAJOR,
            });
          });

          describe('major sixth', () => {
            beforeEach(() => {
              chord.push(9);
            });

            it('describes major sixth chord', () => {
              expect(analyzeIntervals(chord)).toEqual({
                base: ChordBase.MAJOR,
                extensions: [{
                  type: ChordExtensionType.MAJOR,
                  component: ChordComponent.SIXTH,
                }],
              });
            });
          });

          describe('minor seventh', () => {
            beforeEach(() => {
              chord.push(10);
            });

            it('describes dominant seventh chord', () => {
              expect(analyzeIntervals(chord)).toEqual({
                base: ChordBase.MAJOR,
                extensions: [{
                  type: ChordExtensionType.DOMINANT,
                  component: ChordComponent.SEVENTH,
                }],
              });
            });
          });

          describe('major seventh', () => {
            beforeEach(() => {
              chord.push(11);
            });

            it('describes major seventh chord', () => {
              expect(analyzeIntervals(chord)).toEqual({
                base: ChordBase.MAJOR,
                extensions: [{
                  type: ChordExtensionType.MAJOR,
                  component: ChordComponent.SEVENTH,
                }],
              });
            });
          });
        });

        describe('diminished fifth', () => {
          beforeEach(() => {
            chord.push(6);
          });

          describe('minor seventh', () => {
            beforeEach(() => {
              chord.push(10);
            });

            it('describes dominant seventh lowered fifth chord', () => {
              expect(analyzeIntervals(chord)).toEqual({
                base: ChordBase.MAJOR,
                modifications: [{
                  type: ChordModificationType.LOWERED,
                  component: ChordComponent.FIFTH,
                }],
                extensions: [{
                  type: ChordExtensionType.DOMINANT,
                  component: ChordComponent.SEVENTH,
                }],
              });
            });
          });

          describe('major seventh', () => {
            beforeEach(() => {
              chord.push(11);
            });

            it('describes major seventh lowered fifth chord', () => {
              expect(analyzeIntervals(chord)).toEqual({
                base: ChordBase.MAJOR,
                modifications: [{
                  type: ChordModificationType.LOWERED,
                  component: ChordComponent.FIFTH,
                }],
                extensions: [{
                  type: ChordExtensionType.MAJOR,
                  component: ChordComponent.SEVENTH,
                }],
              });
            });
          });
        });

        describe('augmented fifth', () => {
          beforeEach(() => {
            chord.push(8);
          });

          it('determines augmented chord', () => {
            expect(analyzeIntervals(chord)).toEqual({
              base: ChordBase.AUGMENTED,
            });
          });

          describe('minor seventh', () => {
            beforeEach(() => {
              chord.push(10);
            });

            it('describes augmented dominant seventh chord', () => {
              expect(analyzeIntervals(chord)).toEqual({
                base: ChordBase.AUGMENTED,
                extensions: [{
                  type: ChordExtensionType.DOMINANT,
                  component: ChordComponent.SEVENTH,
                }],
              });
            });
          });

          describe('major seventh', () => {
            beforeEach(() => {
              chord.push(11);
            });

            it('describes augmented major seventh chord', () => {
              expect(analyzeIntervals(chord)).toEqual({
                base: ChordBase.AUGMENTED,
                extensions: [{
                  type: ChordExtensionType.MAJOR,
                  component: ChordComponent.SEVENTH,
                }],
              });
            });
          });
        });
      });

      describe('minor third', () => {
        beforeEach(() => {
          chord.push(3);
        });

        describe('perfect fifth', () => {
          beforeEach(() => {
            chord.push(7);
          });

          it('determines minor chord', () => {
            expect(analyzeIntervals(chord)).toEqual({
              base: ChordBase.MINOR,
            });
          });

          describe('major sixth', () => {
            beforeEach(() => {
              chord.push(9);
            });

            it('describes minor sixth chord', () => {
              expect(analyzeIntervals(chord)).toEqual({
                base: ChordBase.MINOR,
                extensions: [{
                  type: ChordExtensionType.MAJOR,
                  component: ChordComponent.SIXTH,
                }],
              });
            });
          });

          describe('minor seventh', () => {
            beforeEach(() => {
              chord.push(10);
            });

            it('describes minor seventh chord', () => {
              expect(analyzeIntervals(chord)).toEqual({
                base: ChordBase.MINOR,
                extensions: [{
                  type: ChordExtensionType.DOMINANT,
                  component: ChordComponent.SEVENTH,
                }],
              });
            });
          });

          describe('major seventh', () => {
            beforeEach(() => {
              chord.push(11);
            });

            it('describes minor major seventh chord', () => {
              expect(analyzeIntervals(chord)).toEqual({
                base: ChordBase.MINOR,
                extensions: [{
                  type: ChordExtensionType.MAJOR,
                  component: ChordComponent.SEVENTH,
                }],
              });
            });
          });
        });

        describe('diminished fifth', () => {
          beforeEach(() => {
            chord.push(6);
          });

          it('determines diminished chord', () => {
            expect(analyzeIntervals(chord)).toEqual({
              base: ChordBase.DIMINISHED,
            });
          });

          describe('diminished seventh', () => {
            beforeEach(() => {
              chord.push(9);
            });

            it('describes diminished seventh chord', () => {
              expect(analyzeIntervals(chord)).toEqual({
                base: ChordBase.DIMINISHED,
                extensions: [{
                  type: ChordExtensionType.DIMINISHED,
                  component: ChordComponent.SEVENTH,
                }],
              });
            });
          });

          describe('minor seventh', () => {
            beforeEach(() => {
              chord.push(10);
            });

            it('describes diminished dominant seventh (half-diminished) chord', () => {
              expect(analyzeIntervals(chord)).toEqual({
                base: ChordBase.DIMINISHED,
                extensions: [{
                  type: ChordExtensionType.DOMINANT,
                  component: ChordComponent.SEVENTH,
                }],
              });
            });
          });

          describe('major seventh', () => {
            beforeEach(() => {
              chord.push(11);
            });

            it('describes diminished major seventh chord', () => {
              expect(analyzeIntervals(chord)).toEqual({
                base: ChordBase.DIMINISHED,
                extensions: [{
                  type: ChordExtensionType.MAJOR,
                  component: ChordComponent.SEVENTH,
                }],
              });
            });
          });
        });
      });
    });
  });

  describe('extensions', () => {
    it('analyzes complete ninth chords', () => {
      expect(analyzeIntervals([0, 4, 7, 10, 14])).toEqual({
        base: ChordBase.MAJOR,
        extensions: [
          {
            type: ChordExtensionType.DOMINANT,
            component: ChordComponent.SEVENTH,
          },
          {
            type: ChordExtensionType.MAJOR,
            component: ChordComponent.NINTH,
          },
        ],
      });
    });

    it('analyzes incomplete ninth chords', () => {
      expect(analyzeIntervals([0, 4, 7, 14])).toEqual({
        base: ChordBase.MAJOR,
        extensions: [
          {
            type: ChordExtensionType.MAJOR,
            component: ChordComponent.NINTH,
          },
        ],
        omissions: [ChordComponent.SEVENTH],
      });

      expect(analyzeIntervals([0, 4, 14])).toEqual({
        base: ChordBase.MAJOR,
        extensions: [
          {
            type: ChordExtensionType.MAJOR,
            component: ChordComponent.NINTH,
          },
        ],
        omissions: [ChordComponent.FIFTH, ChordComponent.SEVENTH],
      });
    });
  });

  describe('naming', () => {
    it('names major chords', () => {
      expect(getChordName(analyzeIntervals([0, 4, 7]))).toBe('');
    });

    it('names minor chords', () => {
      expect(getChordName(analyzeIntervals([0, 3, 7]))).toBe('minor');
    });

    it('names augmented chords', () => {
      expect(getChordName(analyzeIntervals([0, 4, 8]))).toBe('augmented');
    });

    it('names diminished chords', () => {
      expect(getChordName(analyzeIntervals([0, 3, 6]))).toBe('diminished');
    });

    it('names major seventh chords', () => {
      expect(getChordName(analyzeIntervals([0, 4, 7, 11]))).toBe('major seventh');
    });

    it('names minor seventh chords', () => {
      expect(getChordName(analyzeIntervals([0, 3, 7, 10]))).toBe('minor seventh');
    });

    it('names dominant seventh chords', () => {
      expect(getChordName(analyzeIntervals([0, 4, 7, 10]))).toBe('seventh');
    });

    it('names major ninth chords', () => {
      expect(getChordName(analyzeIntervals([0, 4, 7, 11, 14]))).toBe('major seventh ninth');
    });

    it('names minor ninth chords', () => {
      expect(getChordName(analyzeIntervals([0, 3, 7, 10, 14]))).toBe('minor seventh ninth');
    });

    it('names dominant ninth chords', () => {
      expect(getChordName(analyzeIntervals([0, 4, 7, 10, 14]))).toBe('seventh ninth');
    });

    it('names major eleventh chords', () => {
      expect(getChordName(analyzeIntervals([0, 4, 7, 11, 14, 18]))).toBe('major seventh ninth eleventh');
    });

    it('names minor eleventh chords', () => {
      expect(getChordName(analyzeIntervals([0, 3, 7, 10, 14, 18]))).toBe('minor seventh ninth eleventh');
    });

    it('names dominant eleventh chords', () => {
      expect(getChordName(analyzeIntervals([0, 4, 7, 10, 14, 18]))).toBe('seventh ninth eleventh');
    });

    it('names major thirteenth chords', () => {
      expect(getChordName(analyzeIntervals([0, 4, 7, 11, 14, 18, 21]))).toBe('major seventh ninth eleventh thirteenth');
    });

    it('names minor thirteenth chords', () => {
      expect(getChordName(analyzeIntervals([0, 3, 7, 10, 14, 18, 21]))).toBe('minor seventh ninth eleventh thirteenth');
    });

    it('names dominant thirteenth chords', () => {
      expect(getChordName(analyzeIntervals([0, 4, 7, 10, 14, 18, 21]))).toBe('seventh ninth eleventh thirteenth');
    });
  });
});