What version of Elysia is running?
1.4.28
What platform is your computer?
Darwin 25.3.0 arm64 arm
What environment are you using
1.3.9
Are you using dynamic mode?
No
What steps can reproduce the bug?
Create an Elysia app using @elysiajs/openapi and define a request body using ArkType with a string.date field. Then start the server and open /openapi route.
Minimal reproduction:
import { Elysia, t } from "elysia";
import { openapi } from "@elysiajs/openapi";
import { type } from "arktype";
const app = new Elysia()
.use(openapi())
.post(
"/bug",
() => {
ok: true;
},
{
body: type({
date: "string.date",
}),
},
)
.listen(3000);Run the app → OpenAPI generation fails with an error.
For comparison, this works correctly:
.post(
"/non-bug",
() => {
ok: true;
},
{
body: t.Object({
date: t.String({ format: "date-time" }),
}),
},
)What is the expected behavior?
OpenAPI schema should be generated successfully.
The string.date field should be translated into a valid JSON Schema representation and have same description as in typebox case: "the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z"
What do you see instead?
OpenAPI generation crashes with:
ToJsonSchemaError: {
code: "predicate",
base: {
type: "string"
},
predicate: Function(isParsableDate)
}
context: {
code: "predicate",
base: [Object ...],
predicate: [Function: isParsableDate],
},
code: "predicate"
at throw (/Users/umbrien/CodeProjects/date-openapi-bug/node_modules/@ark/schema/out/shared/toJsonSchema.js:36:15)
at reduce (1:11)
at toResolvedJsonSchema (/Users/umbrien/CodeProjects/date-openapi-bug/node_modules/@ark/schema/out/roots/root.js:102:29)
at reduceObjectJsonSchema (/Users/umbrien/CodeProjects/date-openapi-bug/node_modules/@ark/schema/out/structure/structure.js:560:48)
at reduce (1:11)
at toResolvedJsonSchema (/Users/umbrien/CodeProjects/date-openapi-bug/node_modules/@ark/schema/out/roots/root.js:102:29)
at toJsonSchema (/Users/umbrien/CodeProjects/date-openapi-bug/node_modules/@ark/schema/out/roots/root.js:75:36)
at unwrapSchema (/Users/umbrien/CodeProjects/date-openapi-bug/node_modules/@elysiajs/openapi/dist/index.mjs:2973:59)
at toOpenAPISchema (/Users/umbrien/CodeProjects/date-openapi-bug/node_modules/@elysiajs/openapi/dist/index.mjs:3198:20)
at openAPISchema (/Users/umbrien/CodeProjects/date-openapi-bug/node_modules/@elysiajs/openapi/dist/index.mjs:10258:9)
Additional information
Minimal reproduction repo: https://github.com/Umbrien/elysia-arktype-date-openapi-bug-report
Have you try removing the node_modules and bun.lockb and try again yet?
No
What version of Elysia is running?
1.4.28
What platform is your computer?
Darwin 25.3.0 arm64 arm
What environment are you using
1.3.9
Are you using dynamic mode?
No
What steps can reproduce the bug?
Create an Elysia app using
@elysiajs/openapiand define a request body using ArkType with astring.datefield. Then start the server and open/openapiroute.Minimal reproduction:
Run the app → OpenAPI generation fails with an error.
For comparison, this works correctly:
What is the expected behavior?
OpenAPI schema should be generated successfully.
The
string.datefield should be translated into a valid JSON Schema representation and have same description as in typebox case: "the date-time notation as defined by RFC 3339, section 5.6, for example, 2017-07-21T17:32:28Z"What do you see instead?
OpenAPI generation crashes with:
Additional information
Minimal reproduction repo: https://github.com/Umbrien/elysia-arktype-date-openapi-bug-report
Have you try removing the
node_modulesandbun.lockband try again yet?No