Free TypeScript Type Safety Learning Path
The type boundary

GOAL
Create a typed parser for an unknown registration payload and represent success and failure with a discriminated union.

START
Read workbook.html, inspect case-data.csv, complete the five stage outputs, then the capstone. Use evidence-log.csv to record only actions actually performed.

CASE
A fictional registration endpoint receives unknown JSON values. A valid payload has a nonblank string name and an integer seats value from 1 to 4. Type assertions alone cannot validate incoming runtime data. The local exercise sends nothing to a server.

TOOLS
Basic JavaScript functions and objects. A local Node.js and TypeScript setup is needed for compiler exercises.

LOCAL COMMANDS / OPENING
tsc -p tsconfig.json (requires a locally installed TypeScript compiler)

ASSESSMENT
Score at least 80/100, supply every required artifact, and satisfy the path-specific critical condition. Rework missing evidence before marking complete.
Critical condition: No unchecked assertion or any bypasses the external-data boundary.

SOURCE COURSES
Free Simplilearn Course: TypeScript for Web and Node.js Development — https://wikifree.com/courses/free-simplilearn-typescript-for-web-and-node-js-development/

RIGHTS AND SCOPE
Original WikiFree teaching case and exercises. All case data are synthetic. Provider lessons are linked, not redistributed. No certificate, real project delivery or unperformed runtime test is claimed.
