I wrote about a problem that's been bugging me with #Commander.js and #Yargs: .conflicts() and .implies() enforce constraints at runtime, but the type you get back is still a flat object with every field optional. The compiler has no idea which options belong together.

The post walks through what happens when you express the same constraints in the parser structure instead, and how #TypeScript turns that into a discriminated union where each branch carries only its own fields.

Second half covers a less obvious question: what happens when values come from env vars, config files, or prompts instead of argv, and whether the constraints should still hold across all of them.

https://hackers.pub/@hongminhee/2026/optique-10-discriminated-unions-for-cli

#JavaScript #CLI #Optique

From five optional fields to a discriminated union: CLI parsing with Optique 1.0

https://hackers.pub/@hongminhee/2026/optique-10-discriminated-unions-for-cli

Today, I want to talk about my first-ever Commander deck, a Spirit tribal deck led by Millicent, Restless Revenant. It uses cards like Clarion Spirit and Priest of the Blessed Graf alongside the commander to create tons of Spirits.

You draw cards with Bident of Thassa or Distant Memory so that you can cast more Spirits. Finish the game with anthem effects like Mirror Entity or Banner of Kinship.

Check it out: https://archidekt.com/decks/5981580/great_spirits

What’s your favourite tribal deck?

#MTG #EDH #COMMANDER