TypeScript / Advanced · Free and public
Advanced TypeScript in 7 Days
Design a typed event gateway with derived contracts, validated domain values, safe dispatch and public consumer tests.
Start Day 1 →Build on what you know
Prerequisites: TypeScript intermediate, including mapped types, unknown decoders, generic callbacks and compile-time tests. JavaScript advanced is optional. The first lesson links to focused refreshers. Plan extra sessions whenever a prerequisite needs practice.
30 lessons over seven days. Plan around 60–90 minutes per day for worked explanations, prediction, contrasting cases and independent practice; the exact suggested total appears below each day. Delayed review is extra. These are proposed active-study budgets, not measured completion times.
Real TypeScript diagnostics run locally before execution. Await async work explicitly; these editors are single-file ES modules. A single audited brand assertion follows runtime validation; assertions never replace the input checks. No account or external API required.
Use hints before solutions, change inputs, and return after a delay. Completion is saved in this browser separately from other courses. Editor edits are not automatically persisted. Download the tested modular project for optional Node.js 22+ local work.
Day 1 · About 70 minutes
Conditional Types
Derive useful relationships with conditionals, distribution and infer.
- Conditional Types 12 min · Read, predict, build and test
- Union Distribution 20 min · Read, predict, build and test
- infer & Derived Types 13 min · Read, predict, build and test
- Checkpoint: Decoder Types 25 min · Independent practice
Day 2 · About 75 minutes
Mapped API Contracts
Transform modifiers and keys while preserving each callback input.
- Mapped Modifiers 17 min · Read, predict, build and test
- Key Remapping 15 min · Read, predict, build and test
- Typed Registries 18 min · Read, predict, build and test
- Checkpoint: Event Formatters 25 min · Independent practice
Day 3 · About 70 minutes
Validated Domain Values
Establish branded ids and controlled inference with explicit runtime evidence.
- Branded IDs 12 min · Read, predict, build and test
- Assertion Functions 20 min · Read, predict, build and test
- Literal Inference & NoInfer 13 min · Read, predict, build and test
- Checkpoint: Validated Payloads 25 min · Independent practice
Day 4 · About 80 minutes
Correlated Events
Derive paired event unions and dispatch safely to typed channels.
- Derived Event Unions 17 min · Read, predict, build and test
- Correlation & Dispatch 20 min · Read, predict, build and test
- Callback Contracts 18 min · Read, predict, build and test
- Checkpoint: Typed Channels 25 min · Independent practice
Day 5 · About 80 minutes
Library Lifetime & Failures
Distinguish async types, synchronous callback returns, disposal and failure boundaries.
- Awaited & Async Boundaries 17 min · Read, predict, build and test
- void & Callback Returns 20 min · Read, predict, build and test
- Disposal & Lifetime 18 min · Read, predict, build and test
- Checkpoint: Gateway Failures 25 min · Independent practice
Day 6 · About 75 minutes
Public Contract Evidence
Check generated declarations, consumer misuse and runtime invariants.
- Public Type Tests 17 min · Read, predict, build and test
- Runtime Contract Tests 20 min · Read, predict, build and test
- Declarations & Package Exports 13 min · Read, predict, build and test
- Checkpoint: Regression Evidence 25 min · Independent practice
Day 7 · About 75 minutes
Ship a Typed Event Gateway
Run a real modular library, test its limits and solve a fresh settings patch brief.
- Capstone: Typed Event Gateway 10 min · Read, predict, build and test
- Tests & Mutation Lab 15 min · Read, predict, build and test
- Modules & Local Use 15 min · Read, predict, build and test
- Extending Event Contracts 15 min · Read, predict, build and test
- On Your Own: Settings Patches 20 min · Independent practice
- Come Back Later: Review Challenges 20 min · Return later · extra review