Generics, Unions & Utility Types

Generics, Unions & Utility Types

Building Custom Utility Types

Exclude and Extract Distribute Over Unions

Composing Multiple Utility Types

Utility Types Built From Type Operators

String Manipulation Utility Types

Awaited<T> Unwraps Promise Types

ThisParameterType and OmitThisParameter

InstanceType<T> Extracts Instance Types

ConstructorParameters<T> Extracts Constructor Args

Parameters<T> Extracts Argument Types

ReturnType<T> Extracts Return Types

NonNullable<T> Strips Null and Undefined

Extract<T, U> Keeps Matching Union Members

Exclude<T, U> Removes Union Members

Omit<T, K> Excludes Properties

Pick<T, K> Selects a Subset

Record<K, T> Maps Keys to Values

Readonly<T> Locks Every Property

Required<T> Makes Properties Required

Partial<T> Makes Properties Optional

Partial and Required Modifiers

Record with Union Keys

ThisParameterType and OmitThisParameter

ConstructorParameters basics

Composing utility types

Utility types over unions

Pick/Omit with index signatures

ThisType for contextual this

Implementing utility types

Homomorphic modifier preservation

Omit vs Exclude semantics

Record with literal key sets

Deep Partial and Readonly

Composing utility types

Uncapitalize a class name

Utility types with generics

Lowercase for header names

Pick vs Omit with keyof

Capitalize a name literal

Uppercase for HTTP methods

ThisType for contextual this

Required makes every property mandatory

Stripping the this parameter

Omit expects a union of keys

ThisParameterType needs a type

ConstructorParameters needs the class type

Partial for update functions

Readonly blocks property assignment

Pick with a non-existent key

Record<K, T>

Omit<T, K>

String Manipulation Utilities

NoInfer<T>