Inversion of Control in Javascript

Transcript

1. Dependency Injection or How I Couldn’t Think of a Better Title
2. export const search = (keyword) => { const repo = new Repo(); return repo.find((record) => { return !!record.text.match(keyword); }); }
3. import { search } from ‘./search’; app.get(“/search”, req, res) { const keyword = req.params.keyword; const record = search(keyword); res.send(record); }
4. import { search } from ‘./search’; describe(‘search’, () => { it(‘returns a record’,() => { const actual = search(‘test’); assert.ok(actual); }); });
5. import { search } from ‘./search’; describe(‘search’, () => { it(‘returns a record’,() => { const actual = search(‘test’); // error! assert.ok(actual); }); });
6. Mike Yockey Sparkbox @myockey
7. Dependency Management • Layered Dependencies • Inversion of Control
8. export const search = (keyword) => { const repo = new Repo(); return repo.find((record) => { return !!record.text.match(keyword); }); }
9. export const search = (keyword, repo) => { return repo.find((record) => { return !!record.text.match(keyword); }); }
10. import { search } from ‘./search’; class DummyRepo { find(callback) { return ‘ok’; } } describe(‘search’,() => { it(‘returns a record’,() => { const actual = search(‘test’, new DummyRepo); assert.ok(actual); }); });