Development Skill
Angular Migration
Migrate from AngularJS to Angular using hybrid mode, incremental component rewriting, and…
$15
TypeScript Advanced Types
Master TypeScript's advanced type system including generics, conditional types, mapped types…
A deep playbook for TypeScript's advanced type system: generics, conditional types, mapped types, template literal types, and the built-in utility types, turned into reusable, production-ready patterns. It shows how to push correctness into compile time so entire classes of runtime bugs simply cannot ship, while keeping type definitions readable instead of cryptic.
$15 one-time
Add to a kit → Prices include 20% VAT. · Forged on real agency work · one-time, no lock-in
- Type Skill
- Category Development
- Delivery Email · instant
- License One-time
Inside the run · no black box
See the actual work before you buy it.
Type safety is earned at design time, not patched in later with as-casts. From discriminated unions through branded IDs to tests for the types themselves, the discipline stacks like this:
- Models state as algebraic types first: discriminated unions (status: success | error | loading) so an exhaustive switch forces every case to be handled at compile time, and a missing branch is a build error rather than a runtime surprise.
- Narrows unknown input through type guards and assertion functions instead of as-casts: value is string predicates and asserts value is T functions combine a runtime check with compile-time narrowing.
- Adds nominal safety where structural typing is dangerous: brands semantically distinct strings (UserId, OrderId, Cents) with a unique symbol so a user ID can never be passed where an order ID belongs.
- Derives types instead of duplicating them: Pick, Omit and intersections compose new shapes from existing ones, mapped types generate getters or readonly variants, conditional types with infer extract return and parameter types, and template literal types make route and event names type-checked strings.
- Applies the house conventions the linter cannot decide: interface for object shapes and public APIs, type for unions and utility computation, kebab-case files, use-prefixed hooks, Action-suffixed server actions, DB snake_case mapped to TS camelCase, and no raw process.env access.
- Verifies the types themselves: AssertEqual type tests pin expected behavior, conditional nesting is capped at 3 levels and split into aliases beyond that, and tsc noEmit in CI is the cheap pre-deploy gate.
One power source. 6 lines out.
typescript-advanced-types · core
core active · 6 lines
- ✓ type-safe api clients with
Type-safe API clients with typed paths, params, and responses
- ✓ discriminated-union stat…
Discriminated-union state machines with exhaustive handling
- ✓ branded types to stop us…
Branded types to stop UserId/OrderId mix-ups at compile time
- ✓ builder patterns that re…
Builder patterns that refuse to build until required fields are set
- ✓ deep readonly / deep par…
Deep readonly / deep partial config objects
- ✓ type guards and assertion
Type guards and assertion functions for safe unknown narrowing
Yours to keep.
Drag time forward. Watch what stays.
Forever
That's what owning means.
The rented stack
ai writing tool: subscription
expired · access lostanalytics suite: subscription
expired · access lostdesign platform: subscription
expired · access lost(nothing left)
Your forge
-
Catch wrong data shapes before deploy, not in production logs
license: perpetual -
Self-documenting types that improve IDE autocomplete and onboarding
license: perpetual -
Fewer hotfixes and less rework from mismatched IDs and states
license: perpetual -
Refactor large codebases with the compiler watching your back
license: perpetual
subscriptions expire · deeds don't
Everything in the box.
Pick a piece up. Watch it work.
Generic constraints and multiple-type-parameter patterns
6 parts · one working system · ships instantly by email
This wasn't forged for everyone.
- Not for you if you'd rather rent a tool than own one.
- Not for you if you want someone else to run your stack.
- Not for you if you're happy guessing.
TypeScript developers building libraries, frameworks, or strongly-typed apps who want compile-time safety without unreadable type soup.
then this was forged for you.Works with
Universal by design: these run in any AI. Delivered in the open Agent Skills + MCP format (native in Claude); ChatGPT, Gemini, Cursor and Copilot adapt the same files their own way.
- Claude Native format
- ChatGPT Adapts via open standards
- Gemini Adapts via open standards
- Cursor Adapts via open standards
- Copilot Adapts via open standards
Catch what's on your mind.
the air is clear. nothing between you and the forge.
catch a spark: the forge will answer
-
My TypeScript is intermediate, will this read as cryptic type wizardry?
The stated goal is the opposite: advanced features turned into six reusable patterns: typed event emitter, API client, safe builder, deep readonly/partial, form validator, discriminated unions, with conventions for keeping definitions readable. You apply working patterns rather than deriving conditional types from scratch.
-
How does a compile-time type actually prevent a runtime bug?
By making the wrong program fail to compile: branded types stop a UserId being passed where an OrderId belongs, exhaustive discriminated unions force every state to be handled, and the safe builder refuses to build until required fields are set. AssertEqual and ExpectError helpers then keep those guarantees tested like code.
-
Does this validate data coming from an API at runtime?
No. Types are erased at compile time, so a malformed JSON response sails past them, external data still needs a runtime validator. What you do get are type guards and assertion functions for safely narrowing unknown once a runtime check has run.
-
How is it delivered?
By email right after purchase: ready to run, downloaded instantly, no setup wait.
-
One-time or subscription?
A one-time purchase; no subscription or hidden fees. VAT (20%) is included.
-
Can I get a refund?
As a digital product, it can’t be refunded once downloaded. That’s why we show exactly what’s inside and who it’s for, right here.