abc-notation-transposition/tests/unit/funcs/transposition-utils/get-pitch-letter.test.js

A robust utility for transposing ABC Notation by half steps.

const {getPitchLetter} = require('../../../../functions/transposition-utils');

test('Expect getPitchLetter to return a capital letter from A-G when passed a pitch.', () => {
    expect(getPitchLetter('c')).toBe('C');
    expect(getPitchLetter('=c')).toBe('C');
    expect(getPitchLetter('_D')).toBe('D');
    expect(getPitchLetter('^d')).toBe('D');
    expect(getPitchLetter('__e')).toBe('E');
    expect(getPitchLetter('^^E,,,')).toBe('E');
    expect(getPitchLetter("f'''")).toBe('F');
    expect(getPitchLetter('g')).toBe('G');
    expect(getPitchLetter('__A,')).toBe('A');
    expect(getPitchLetter('_b')).toBe('B');
});

test('Expect getPitchLetter to throw an error if an invalid pitch is passed in as an argument.', () => {
    expect(() => getPitchLetter('_Q,,,')).toThrow(new Error("Pitch _Q,,, must contain a letter between a and g (case insensitive)."));
});