feat: improve type coverage for InferParam (#43)

Author: himself65

src/context.ts

@@ -7,7 +7,7 @@ import type {
 	Prettify,
 	UnionToIntersection,
 } from "./helper";
-import type { Middleware, MiddlewareOptions } from "./middleware";
+import type { Middleware, MiddlewareContext, MiddlewareOptions } from "./middleware";
 import { runValidation } from "./validator";
 import {
 	getCookieKey,
@@ -107,7 +107,7 @@ export type InferInputMethod<
 export type InferParam<Path extends string> = IsEmptyObject<
 	InferParamPath<Path> & InferParamWildCard<Path>
 > extends true
-	? Record<string, any> | undefined
+	? {}
 	: Prettify<InferParamPath<Path> & InferParamWildCard<Path>>;
 
 export type InferParamInput<Path extends string> = IsEmptyObject<

src/helper.ts

@@ -43,5 +43,5 @@ export type InferParamWildCard<Path> = Path extends
 	: Path extends `${infer _Start}/*`
 		? { [K in "_"]: string }
 		: Path extends `${infer _Start}/${infer Rest}`
-			? InferParamPath<Rest>
+			? InferParamWildCard<Rest>
 			: {};

src/type.test.ts

@@ -0,0 +1,45 @@
+import { describe, expectTypeOf, it } from "vitest";
+import type { InferParam } from "./context";
+import type { InferParamPath, InferParamWildCard } from "./helper";
+
+describe("infer param", () => {
+	it("empty path", () => {
+		expectTypeOf<InferParamPath<"/">>().toEqualTypeOf<{}>();
+		expectTypeOf<InferParamWildCard<"/">>().toEqualTypeOf<{}>();
+		expectTypeOf<InferParam<"/">>().toEqualTypeOf<{}>();
+	});
+	it("static path", () => {
+		expectTypeOf<InferParamPath<"/static/path">>().toEqualTypeOf<{}>();
+		expectTypeOf<InferParamWildCard<"/static/path">>().toEqualTypeOf<{}>();
+		expectTypeOf<InferParam<"/static/path">>().toEqualTypeOf<{}>();
+	});
+	it("single param", () => {
+		expectTypeOf<InferParamPath<"/user/:id">>().toEqualTypeOf<{ id: string }>();
+		expectTypeOf<InferParamWildCard<"/user/:id">>().toEqualTypeOf<{}>();
+		expectTypeOf<InferParam<"/user/:id">>().toEqualTypeOf<{ id: string }>();
+	});
+	it("multiple params", () => {
+		expectTypeOf<InferParamPath<"/user/:userId/post/:postId">>().toEqualTypeOf<{
+			userId: string;
+			postId: string;
+		}>();
+		expectTypeOf<InferParamWildCard<"/user/:userId/post/:postId">>().toEqualTypeOf<{}>();
+		expectTypeOf<InferParam<"/user/:userId/post/:postId">>().toEqualTypeOf<{
+			userId: string;
+			postId: string;
+		}>();
+	});
+	it("wildcard param", () => {
+		expectTypeOf<InferParamPath<"/files/*">>().toEqualTypeOf<{}>();
+		expectTypeOf<InferParamWildCard<"/files/*">>().toEqualTypeOf<{ _: string }>();
+		expectTypeOf<InferParam<"/files/*">>().toEqualTypeOf<{ _: string }>();
+	});
+	it("mixed params", () => {
+		expectTypeOf<InferParamPath<"/user/:userId/files/*">>().toEqualTypeOf<{ userId: string }>();
+		expectTypeOf<InferParamWildCard<"/user/:userId/files/*">>().toEqualTypeOf<{ _: string }>();
+		expectTypeOf<InferParam<"/user/:userId/files/*">>().toEqualTypeOf<{
+			userId: string;
+			_: string;
+		}>();
+	});
+});