hsmusic-wiki/test/cacheable-object.js

import test from 'tape';

import CacheableObject from '../src/data/cacheable-object.js';

// Utility

function newCacheableObject(PD) {
    return new (class extends CacheableObject {
        static propertyDescriptors = PD;
    });
}

// Tests

test(`CacheableObject simple separate update & expose`, t => {
    const obj = newCacheableObject({
        number: {
            flags: {
                update: true
            }
        },

        timesTwo: {
            flags: {
                expose: true
            },

            expose: {
                dependencies: ['number'],
                compute: ({ number }) => number * 2
            }
        }
    });

    t.plan(1);
    obj.number = 5;
    t.equal(obj.timesTwo, 10);
});

test(`CacheableObject basic cache behavior`, t => {
    let computeCount = 0;

    const obj = newCacheableObject({
        string: {
            flags: {
                update: true
            }
        },

        karkat: {
            flags: {
                expose: true
            },

            expose: {
                dependencies: ['string'],
                compute: ({ string }) => {
                    computeCount++;
                    return string.toUpperCase();
                }
            }
        }
    });

    t.plan(8);

    t.is(computeCount, 0);

    obj.string = 'hello world';
    t.is(computeCount, 0);

    obj.karkat;
    t.is(computeCount, 1);

    obj.karkat;
    t.is(computeCount, 1);

    obj.string = 'testing once again';
    t.is(computeCount, 1);

    obj.karkat;
    t.is(computeCount, 2);

    obj.string = 'testing once again';
    t.is(computeCount, 2);

    obj.karkat;
    t.is(computeCount, 2);
});

test(`CacheableObject combined update & expose (no transform)`, t => {
    const obj = newCacheableObject({
        directory: {
            flags: {
                update: true,
                expose: true
            }
        }
    });

    t.plan(2);

    t.directory = 'the-world-revolving';
    t.is(t.directory, 'the-world-revolving');

    t.directory = 'chaos-king';
    t.is(t.directory, 'chaos-king');
});

test(`CacheableObject combined update & expose (basic transform)`, t => {
    const obj = newCacheableObject({
        getsRepeated: {
            flags: {
                update: true,
                expose: true
            },

            expose: {
                transform: value => value.repeat(2)
            }
        }
    });

    t.plan(1);

    obj.getsRepeated = 'dog';
    t.is(obj.getsRepeated, 'dogdog');
});

test(`CacheableObject combined update & expose (transform with dependency)`, t => {
    const obj = newCacheableObject({
        customRepeat: {
            flags: {
                update: true,
                expose: true
            },

            expose: {
                dependencies: ['times'],
                transform: (value, { times }) => value.repeat(times)
            }
        },

        times: {
            flags: {
                update: true
            }
        }
    });

    t.plan(3);

    obj.customRepeat = 'dog';
    obj.times = 1;
    t.is(obj.customRepeat, 'dog');

    obj.times = 5;
    t.is(obj.customRepeat, 'dogdogdogdogdog');

    obj.customRepeat = 'cat';
    t.is(obj.customRepeat, 'catcatcatcatcat');
});

test(`CacheableObject validate on update`, t => {
    const mockError = new TypeError(`Expected a string, not ${typeof value}`);

    const obj = newCacheableObject({
        directory: {
            flags: {
                update: true,
                expose: true
            },

            update: {
                validate: value => {
                    if (typeof value !== 'string') {
                        throw mockError;
                    }
                    return true;
                }
            }
        },

        date: {
            flags: {
                update: true,
                expose: true
            },

            update: {
                validate: value => (value instanceof Date)
            }
        }
    });

    let thrownError;
    t.plan(6);

    obj.directory = 'megalovania';
    t.is(obj.directory, 'megalovania');

    try {
        obj.directory = 25;
    } catch (err) {
        thrownError = err;
    }

    t.is(thrownError, mockError);
    t.is(obj.directory, 'megalovania');

    const date = new Date(`25 December 2009`);

    obj.date = date;
    t.is(obj.date, date);

    try {
        obj.date = `TWELFTH PERIGEE'S EVE`;
    } catch (err) {
        thrownError = err;
    }

    t.is(thrownError?.constructor, TypeError);
    t.is(obj.date, date);
});

test(`CacheableObject default update property value`, t => {
    const obj = newCacheableObject({
        fruit: {
            flags: {
                update: true,
                expose: true
            },

            update: {
                default: 'potassium'
            }
        }
    });

    t.plan(1);
    t.is(obj.fruit, 'potassium');
});

test(`CacheableObject default property throws if invalid`, t => {
    const mockError = new TypeError(`Expected a string, not ${typeof value}`);

    t.plan(1);

    let thrownError;

    try {
        newCacheableObject({
            string: {
                flags: {
                    update: true
                },

                update: {
                    default: 123,
                    validate: value => {
                        if (typeof value !== 'string') {
                            throw mockError;
                        }
                        return true;
                    }
                }
            }
        });
    } catch (err) {
        thrownError = err;
    }

    t.is(thrownError, mockError);
});