Logo

Tag: TypeScript Generics

TypeScript Utility Types Part 3: Extract, Exclude, and NonNullable

May 25, 2020
intersecting-types
TypeScript utility types provide built in type composition tools to generate new types. They capitalize on TypeScript generic types to enable this functionality. In the third part of this series, we will be covering the , , and utilities. For more coverage on other utility types, check out the previous two posts in the series. TypeScript Utility Types Part 1: Partial, Pick, and Omit TypeScript Utility Types Part 2: Record, Readonly, & Required Extract . is a utility for pulling out values that are shared between the two type arguments it receives. This can be useful for refining types for other implementations, or to remove types that another implementation may not accept. By using on the two user interfaces, we have a type of the three…
Read More

TypeScript Utility Types Part 2: Record, Readonly, & Required

May 4, 2020
reflective-architecture-perspective
TypeScript utility types provide built in type composition tools to generate new types. They capitalize on TypeScript generic types to enable this functionality. Previously we talked about the , , and types as well as utility types as a concept in part 1 of this series. In this post we will dive into three more of the utility types provided by TypeScript: , , and . Record is the first utility type we have covered that takes two generic types. This utility generates a type with the properties present in with the corresponding values of type . This utility can be helpful in create type objects from union strings, or even generic polymorphic types. is a very flexible utility type and can eliminate a lot of duplication if you already have…
Read More

TypeScript Utility Types Part 1: Partial, Pick, and Omit

April 27, 2020
compass-with-leather-notebook
TypeScript provides multiple means of creating, modifying, and extending existing types into new variants using special utility types. Most of these types utilize generic types under the hood, but a deep understanding of generics is not necessary to utilize them. We can think of utility types as TypeScript functions to return new types. In this post, I'll cover three of the utility types that I use often as well as some examples of how they can be leveraged. These types include: , , and . If you are not familiar with TypeScript generics, here is a quick overview to better understand the documentation. TypeScript generics are indicated through placing a type variable inside . An example of this is . In this instance, we can think of as a…
Read More
2020 Daniel Lemay. All Rights Reserved.