design-patterns – Page 8 – Türker Yıldırım

The factory that took a DTO and returned another DTO

NoteJanuary 9, 20232 min read

A class named OrderFactory whose only method mapped one flat structure onto another flat structure with different field names. The name mattered more than it should have: three…

Readonly classes and the DTO that stopped needing a constructor

Deep diveDecember 20, 202210 min read

8.2 on 8 December, and readonly applied to a whole class. readonly on every property, written out forty times.

The dynamic property that had been a typo since 2016

Deep diveDecember 13, 202214 min read

8.2 on 8 December deprecates dynamic properties, and the deprecation is the feature. $order->totl has been silently creating a property for six years.

An event is past tense and cannot be refused

NoteNovember 23, 20221 min read

The naming convention decides who is allowed to fail, which is why it is worth more than a style rule. A handler for OrderPlaced that throws does not…

A design system in theme.json and a stylesheet that agrees

Deep diveNovember 17, 202210 min read

6.1, fluid typography, and a stylesheet that had its own scale. Two definitions of a spacing scale, one in each place.

Natural idempotency, and when no claim table is needed

NoteNovember 16, 20221 min read

Some operations are safe to repeat by construction, and recognising them saves a table and a transaction. Setting a value is safe and adjusting one is not, which…

An enum case cannot carry state, and that is deliberate

NoteSeptember 30, 20222 min read

A case is a singleton, so a mutable property on it would be shared by every reference in the process, and the language forbids properties outright rather than…

Bootstrap 5.2, CSS variables, and a theme that stopped being a fork

Deep diveAugust 17, 202210 min read

5.2 in July, and custom properties throughout the components. A Sass fork that had to be rebased on every patch release.

Block locking, and the page an editor cannot break

Deep diveJune 29, 20229 min read

6.0, and locking that is per block rather than per template. templateLock all was too much and nothing was too little.

A discriminated union beats four optional properties

NoteMay 19, 20222 min read

An interface where four properties are optional describes many states that cannot occur, and the type system cannot help with any of them. Narrowing on the discriminant is…