import { describe, it, expect, beforeEach } from 'vitest';
// Simulate the snapshot version logic for testing
let snapshotVersion = 0;
function getCurrentSnapshotVersion(): number {
return snapshotVersion;
}
function incrementSnapshotVersion(): number {
return ++snapshotVersion;
}
function resetSnapshotVersion(): void {
snapshotVersion = 0;
}
// Validate that UID is from current snapshot version
function validateUid(uid: string): void {
const parts = uid.split('_');
if (parts.length !== 2) {
throw new Error(`Invalid UID format: ${uid}. Expected format: version_index (e.g., "1_0").`);
}
const uidVersion = parseInt(parts[0], 10);
const currentVersion = getCurrentSnapshotVersion();
if (isNaN(uidVersion)) {
throw new Error(`Invalid UID format: ${uid}. Version must be a number.`);
}
if (currentVersion === 0) {
throw new Error('No snapshot taken yet. Call takeSnapshot first.');
}
if (uidVersion !== currentVersion) {
throw new Error(
`This UID (${uid}) is from a stale snapshot (version ${uidVersion}). ` +
`Current snapshot version is ${currentVersion}. Take a new snapshot first.`
);
}
}
describe('Snapshot Version System', () => {
beforeEach(() => {
resetSnapshotVersion();
});
describe('Version Counter', () => {
it('should start at 0', () => {
expect(getCurrentSnapshotVersion()).toBe(0);
});
it('should increment correctly', () => {
expect(incrementSnapshotVersion()).toBe(1);
expect(incrementSnapshotVersion()).toBe(2);
expect(incrementSnapshotVersion()).toBe(3);
});
it('should reset correctly', () => {
incrementSnapshotVersion();
incrementSnapshotVersion();
resetSnapshotVersion();
expect(getCurrentSnapshotVersion()).toBe(0);
});
});
describe('UID Validation', () => {
it('should throw if no snapshot taken yet', () => {
expect(() => validateUid('1_0')).toThrow('No snapshot taken yet');
});
it('should accept valid UID from current snapshot', () => {
incrementSnapshotVersion(); // version = 1
expect(() => validateUid('1_0')).not.toThrow();
expect(() => validateUid('1_5')).not.toThrow();
expect(() => validateUid('1_99')).not.toThrow();
});
it('should reject stale UID from old snapshot', () => {
incrementSnapshotVersion(); // version = 1
incrementSnapshotVersion(); // version = 2
expect(() => validateUid('1_0')).toThrow('stale snapshot (version 1)');
expect(() => validateUid('1_5')).toThrow('stale snapshot');
});
it('should reject UID from future snapshot', () => {
incrementSnapshotVersion(); // version = 1
expect(() => validateUid('5_0')).toThrow('stale snapshot (version 5)');
});
it('should reject invalid UID format - no underscore', () => {
incrementSnapshotVersion();
expect(() => validateUid('ref0')).toThrow('Invalid UID format');
});
it('should reject invalid UID format - old ref_ format', () => {
incrementSnapshotVersion();
expect(() => validateUid('ref_0')).toThrow('Version must be a number');
});
it('should reject invalid UID format - multiple underscores', () => {
incrementSnapshotVersion();
expect(() => validateUid('1_2_3')).toThrow('Invalid UID format');
});
it('should reject non-numeric version', () => {
incrementSnapshotVersion();
expect(() => validateUid('abc_0')).toThrow('Version must be a number');
});
});
describe('UID Format', () => {
it('should generate correct UID format', () => {
const version = incrementSnapshotVersion();
const uid = `${version}_0`;
expect(uid).toBe('1_0');
});
it('should generate unique UIDs per snapshot', () => {
const v1 = incrementSnapshotVersion();
const uid1 = `${v1}_0`;
const v2 = incrementSnapshotVersion();
const uid2 = `${v2}_0`;
expect(uid1).toBe('1_0');
expect(uid2).toBe('2_0');
expect(uid1).not.toBe(uid2);
});
});
});
