TypeScript Risk Assessment & Management 3

Question 1

Which TypeScript utility type is best suited to safely construct a partial update payload, reducing the risk of accidentally omitting required fields in API calls?

Accepted Answer

Partial<T>

Answer

Partial<T> makes all properties optional, which is appropriate for patch/update payloads where only changed fields need to be sent.

Question 2

What risk does enabling 'declaration: true' without also enabling 'declarationMap' introduce for library consumers?

Accepted Answer

Consumers cannot trace type definitions back to source, making debugging harder

Answer

Without declarationMap, the .d.ts files lack source mapping, so consumers cannot jump to the original TypeScript source when debugging type issues.

Question 3

A team uses structural typing and finds two unrelated interfaces accidentally satisfy each other. What risk does this create?

Accepted Answer

Functions may silently accept wrong object types, masking logical errors

Answer

TypeScript's structural typing means any object with matching shape is accepted, so logically different types can be accidentally interchangeable without error.

Question 4

Which technique most effectively reduces the risk of breaking changes when refactoring a public TypeScript API?

Accepted Answer

Using branded/nominal types to prevent implicit substitution between similar shapes

Answer

Branded types add a unique tag that prevents structurally similar types from being used interchangeably, catching misuse at compile time during refactoring.

Question 5

When a TypeScript project uses 'paths' aliases in tsconfig, what deployment risk must be mitigated?

Accepted Answer

Bundlers and Node.js runtimes do not natively resolve paths aliases, requiring additional configuration

Answer

tsconfig paths are a compile-time convenience; runtimes like Node.js and many bundlers need separate plugins or tools to resolve the same aliases.

TypeScript Practice Test

TypeScript Practice Test

TypeScript Risk Assessment & Management 3