TypeScript: Branded Types
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TypeScript: Branded Types
1–10 of 209 posts
Re: TypeScript: Branded Types
#2Amazing, we have invented nominal typing in a structural typing system.
Sometimes I wonder what kind of programs are written using all these complicated TS types. Anecdotally, we use very simple, basic types in our codebase. The need for tricks like this (and other complicated types) is simply not there. Are we doing something wrong?
Re: TypeScript: Branded Types
#3I can see this being useful and it seems about as neat a solution as you can currently get in TypeScript as it stands today, but it’s still cumbersome.
My feeling is that while you can do this, you’re swimming upstream as the language is working against you. Reaching for such a solution should probably be avoided as much as possible.
Re: TypeScript: Branded Types
#4Amazing, we have invented nominal typing in a structural typing system. Sometimes I wonder what kind of programs are written using all these complicated TS types. Anecdotally, we use very simple, basic types in our codebase. The need for tricks like this (and other complicated types) is simply not there. Are we doing something wrong?
Nope, if you have lower expectations for your type system and are using TS then you are properly where you want to be.
Re: TypeScript: Branded Types
#5I can see this being useful and it seems about as neat a solution as you can currently get in TypeScript as it stands today, but it’s still cumbersome. My feeling is that while you can do this, you’re swimming upstream as the language is working against you. Reaching for such a solution should probably be avoided as much as possible.
> as the language is working against you
Right, but this is one of those situations where a reasonable person could conclude "The language is not working to help me solve the problem I'm trying to solve." Sometimes you don't want JavaScript sloppiness and you also don't want TypeScript structural-type "sloppiness," desiring instead nominal types.
This is a clever way to use the existing infrastructure to get nominal types with no additional runtime overhead.
Re: TypeScript: Branded Types
#6Amazing, we have invented nominal typing in a structural typing system. Sometimes I wonder what kind of programs are written using all these complicated TS types. Anecdotally, we use very simple, basic types in our codebase. The need for tricks like this (and other complicated types) is simply not there. Are we doing something wrong?
I use branded types for database id’s to avoid mixing them up. It seems like better documentation and might catch some errors, but mixing up database id’s seems like an uncommon error, so hard to say.
Re: TypeScript: Branded Types
#7Amazing, we have invented nominal typing in a structural typing system. Sometimes I wonder what kind of programs are written using all these complicated TS types. Anecdotally, we use very simple, basic types in our codebase. The need for tricks like this (and other complicated types) is simply not there. Are we doing something wrong?
Probably not.
I could definitely see using something like this to force some constraints on my favorite bugbear for my problem domain: values that should have units. It matters a lot if "time" is nanoseconds, microseconds, or seconds, but most time-related functions just take in "number" like that's okay and won't cause thousand- or million-fold magnitude errors.
This is one way to provide some language safeguarding against treating 5 nanoseconds as the same as 5 microseconds.
Re: TypeScript: Branded Types
#8Amazing, we have invented nominal typing in a structural typing system. Sometimes I wonder what kind of programs are written using all these complicated TS types. Anecdotally, we use very simple, basic types in our codebase. The need for tricks like this (and other complicated types) is simply not there. Are we doing something wrong?
You've never had values that are only valid within a specific context and wanted to prevent using them incorrectly?
Re: TypeScript: Branded Types
#9I can see this being useful and it seems about as neat a solution as you can currently get in TypeScript as it stands today, but it’s still cumbersome. My feeling is that while you can do this, you’re swimming upstream as the language is working against you. Reaching for such a solution should probably be avoided as much as possible.
I don't see why. I greatly prefer typescript's structural typing for almost everything. But id's in data models are an exception, so I use branding for those. It works perfectly, the only overhead is in the write-once declaration and now I am protected from accidentally using an AccountId where a MemberId was expected, even though they are both just strings.
Re: TypeScript: Branded Types
#10Amazing, we have invented nominal typing in a structural typing system. Sometimes I wonder what kind of programs are written using all these complicated TS types. Anecdotally, we use very simple, basic types in our codebase. The need for tricks like this (and other complicated types) is simply not there. Are we doing something wrong?
You don't use them but your favorite libraries do.