ThomasAribart
commented
2 years ago Hello @thomasheartman ๐
Sure no problem ! I think one of the difficulty is that removing readonly from a readonly string[] is not enough to obtain string[] because some mutating methods (like pop or push) are removed from readonly arrays and not re-added by removing the readonly keyword. But you can stick with readonly arrays.
First create a ParseOpenApiParams generic type with correct type constraints:
import type { JSONSchema } from "json-schema-to-ts";
type OpenApiParam = {
readonly name: string;
readonly schema: JSONSchema;
readonly in: "query" | "other"; // (I guess there probably are some other sources here)
};
type ParseOpenApiParams<P extends readonly OpenApiParam[]> = RecurseOnParams<P>;Next, recurse on your array with the following syntax:
import { O, L } from "ts-toolbelt";
type RecurseOnParams<
P extends readonly OpenApiParam[],
R extends O.Object = {}
> = {
continue: RecurseOnParams<
L.Tail<P>,
L.Head<P>["in"] extends "query"
? O.Merge<
R,
{ [key in L.Head<P>["name"]]: FromSchema<L.Head<P>["schema"]> }
>
: R
>;
stop: R;
}[P extends readonly [OpenApiParam, ...OpenApiParam[]] ? "continue" : "stop"];This should work like a charm:
const params = [
{
name: "paramName1",
schema: {
type: "string",
},
in: "query",
},
{
name: "paramName2",
schema: {
type: "string",
},
in: "query",
},
{
name: "paramName3",
schema: {
type: "string",
},
in: "other",
},
] as const;
type parsed = ParseOpenApiParams<typeof params>;
// => { paramName1: string, paramName2: string }
thomasheartman
Hi! First off: thanks for all the effort in creating and maintaining this library!
I have a question that I can't seem to figure out an answer to regarding using this library with express and express-openapi, and that I was hoping you could shed some light on:
In short, I'm wondering if there is a way to create a record from query parameters via FromSchema?
A little more context: the OpenAPI spec requires you to type query parameters as a list of objects. These objects have a name, a type, description, and so forth, but it is a list of spec-like objects. Something like:
For endpoints that accept JSON payloads, using FromSchema to generate types has gone very smoothly, but it seems to be a bit trickier with query parameters. Express types out the request as something like this:
where
QueryParamObjectis an object with query param names as keys and corresponding types.My problem is that I'd like to convert the list of query parameters into something that FromSchema can parse, so that we get a nice generated type based on the schema, but I can't figure out how to do it.
The list is obviously not a schema in and of itself, but it's easy enough to map it so that it becomes the equivalent of a
propertiesobject on an object-type schema. However, I keep running into issues with readonly and type inference and I'm just not making any headway. Do you have any suggestions as to what I could do here?Sorry if this doesn't actually apply to this library. I was not the one who set everything up for the project, so I'm not entirely sure how everything is wired together. I do know, though, that the FromSchema method does a lot of our type conversion and that the internals looked pretty intimidating. It may well be that this is outside of what this package is responsible for , but I thought I'd try this as my first port of call.
Thanks very much for any tips, tricks, and insights you can offer.