Support for transform types

[ehaynes99]

Prerequisites

• I have written a descriptive issue title
• I have searched existing issues to ensure the feature has not already been requested

🚀 Feature Proposal

Now that TypeBox supports transform types, it would be great if this library supported them as well.

Example

I made a branch that should work here: main...ehaynes99:fastify-type-provider-typebox:transform-types

However, this lib currently allows TypeBox versions down to 0.26, and transform types were only added in 0.30. I could work around it for the actual conversion like here:

// Decode added in TypeBox 0.30
const decoded = ('Decode' in Value) ? Value.Decode(schema, converted) : converted

but there's not a way to fix the types, because StaticDecode would not exist in those older versions. In order to merge this, the compatible version range would have to be updated.

diff --git a/package.json b/package.json
index e6af223..783bda7 100644
--- a/package.json
+++ b/package.json
@@ -18,7 +18,7 @@
     }
   },
   "peerDependencies": {
-    "@sinclair/typebox": ">=0.26 <=0.32"
+    "@sinclair/typebox": ">=0.30 <=0.32"
   },
   "scripts": {
     "build:clean": "rimraf ./dist",

[mcollina]

I'm not sure what eversion are you using?

fastify-type-provider-typebox/package.json

Line 21 in c92a5fb

"@sinclair/typebox": ">=0.26 <=0.32"

lists v0.32.

[ehaynes99]

The peer dependency allows a range. E.g. an application could have 0.29, and that would not compile because the StaticDecode type would not exist. The minimum would have to be increased, as applications with >=0.30 <=0.32 would work, but those with >=0.26 <0.30 would not. I went ahead and made a PR with that in it, but wanted to point it out.

fastify-type-provider-typebox/index.mts

Lines 61 to 63 in b5647cb

	export interface TypeBoxTypeProvider extends FastifyTypeProvider {
	output: this['input'] extends TSchema ? StaticDecode<this['input']> : unknown
	}