Work & Development · Frontend Frameworks & TypeScript

TypeScript for Clearer Code

Add types to a goal-tracker feature and check the outside data it receives.

Level: Intermediate
Lessons: 9 lessons in 3 modules
Estimated study: About 10 hours
Format: Online, self-paced

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Before you start

Recommended preparation:

Build Applications with React

Use a computer with a keyboard and a current browser. Individual lessons explain the tools needed for each exercise.

Full study requires active Academy access. This course can be audited independently of optional assessed programs.

About this course

After Build Applications with React, add TypeScript to your goal tracker. In about 10 hours, describe records and function inputs, represent different app states and check data from storage or files. Learn which mistakes types catch and which still need runtime checks.

What you will be able to do

Define types for application data and component inputs.
Use unions and narrowing to model different states.
Explain why external data still needs runtime validation.

Course outline

Describe values, records and function inputs, and learn which types the checker can work out.

Describe values and understand inference1 hFree preview
Define goal records and optional information1 h
Write function contracts that expose failure1 h

Represent one of several states, check unknown values and reuse a function without losing type information.

Represent loading and result states with a union1 h
Narrow unknown values before using them1 h
Write a generic that preserves useful information1 h

Add types to a working React feature and check goal data loaded from storage or a file.

Type a React feature and its input events1 h 30 min
Parse external goal arrays into a trusted shape1 h
Deliver a typed feature with runtime evidence1 h 30 min

Related assessed programs

This course belongs to the following optional programs. Each has its own required course bundle, evidence review and separate fee. Each program page shows its approved fee and current registration status.