nota · mpppk · Sep 17, 2024 · Sep 17, 2024 · Sep 17, 2024 · Sep 17, 2024
diff --git a/src/common/spec.ts b/src/common/spec.ts
@@ -23,6 +23,7 @@ export const Method = [
   "head",
 ] as const;
 export type Method = (typeof Method)[number];
+export type CaseInsensitive<S extends string> = Uppercase<S> | Lowercase<S>;
 export type CaseInsensitiveMethod = Method | Uppercase<Method>;
 export const isMethod = (x: unknown): x is Method =>
   Method.includes(x as Method);

diff --git a/src/fetch/index.t-test.ts b/src/fetch/index.t-test.ts
@@ -14,9 +14,9 @@ const JSONT = JSON as JSONT;
   (async () => {
     const f = fetch as FetchT<"", Spec>;
     {
-      // TODO: 今はinitを省略する場合undefinedを明示的に渡す必要があるが、なんとかしたい
+      // TODO: 今はinitの省略ができないが、できるようにしたい
       // methodを省略した場合はgetとして扱う
-      const res = await f("/users", undefined);
+      const res = await f("/users", {});
       (await res.json()).prop;
     }
   })();
@@ -110,7 +110,7 @@ const JSONT = JSON as JSONT;
     }
 
     {
-      // TODO: 今は定義していないメソッドを受け付けてしまうが、いつかなんとかしたい
+      // @ts-expect-error 定義されていないmethodは指定できない
       await f("/users", { method: "patch" });
     }
   })();
@@ -151,7 +151,7 @@ const JSONT = JSON as JSONT;
   }>;
   (async () => {
     const f = fetch as FetchT<"", Spec>;
-    // TODO: getが定義されていない場合、methodを省略したらエラーになってほしいが今はならない
+    // @ts-expect-error getが定義されていない場合、methodは省略できない
     await f(`/users`, {});
   })();
 }
@@ -208,6 +208,34 @@ const JSONT = JSON as JSONT;
   })();
 }
 
+{
+  type Spec = DefineApiEndpoints<{
+    "/packages/list": {
+      get: {
+        responses: { 200: { body: { prop: string } } };
+        query: { state?: boolean };
+      };
+    };
+  }>;
+  (async () => {
+    const basePath = "/api/projects/:projectName/workflow";
+    const f = fetch as FetchT<typeof basePath, Spec>;
+    {
+      const res = await f(
+        `/api/projects/projectA/workflow/packages/list?state=true`,
+        {},
+      );
+      if (res.ok) {
+        (await res.json()).prop;
+      }
+    }
+    {
+      // query parameter can be omitted because it is optional
+      f(`/api/projects/projectA/workflow/packages/list`, {});
+    }
+  })();
+}
+
 {
   type Spec = DefineApiEndpoints<{
     "/vectorize/indexes/:indexName": {

diff --git a/src/fetch/index.ts b/src/fetch/index.ts
@@ -1,6 +1,5 @@
 import {
   ApiEndpoints,
-  ApiHasP,
   ApiP,
   AnyApiResponses,
   CaseInsensitiveMethod,
@@ -13,6 +12,7 @@ import {
   Replace,
   StatusCode,
   IsAllOptional,
+  CaseInsensitive,
 } from "../common";
 import { UrlPrefixPattern, ToUrlParamPattern } from "../common";
 import { TypedString } from "../json";
@@ -22,10 +22,12 @@ export type RequestInitT<
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   Body extends Record<string, any> | undefined,
   HeadersObj extends Record<string, string> | undefined,
-> = Omit<RequestInit, "method" | "body" | "headers"> & {
-  method?: InputMethod;
+> = Omit<RequestInit, "method" | "body" | "headers"> &
+  (InputMethod extends "get" | "GET"
+    ? { method?: InputMethod }
+    : { method: InputMethod }) &
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
-} & (Body extends Record<string, any>
+  (Body extends Record<string, any>
     ? IsAllOptional<Body> extends true
       ? { body?: Body | TypedString<Body> }
       : { body: TypedString<Body> }
@@ -42,17 +44,24 @@ export type RequestInitT<
  * FetchT is a type for window.fetch like function but more strict type information
  */
 type FetchT<UrlPrefix extends UrlPrefixPattern, E extends ApiEndpoints> = <
+  UrlPattern extends ToUrlParamPattern<`${UrlPrefix}${keyof E & string}`>,
   Input extends Query extends undefined
-    ? ToUrlParamPattern<`${UrlPrefix}${keyof E & string}`>
-    : `${ToUrlParamPattern<`${UrlPrefix}${keyof E & string}`>}?${string}`,
+    ? UrlPattern
+    : IsAllOptional<Query> extends true
+      ? UrlPattern | `${UrlPattern}?${string}`
+      : `${UrlPattern}?${string}`,
   InputPath extends PathToUrlParamPattern<
     NormalizePath<
       ParseURL<Replace<Input, ToUrlParamPattern<UrlPrefix>, "">>["path"]
     >
   >,
   CandidatePaths extends string = MatchedPatterns<InputPath, keyof E & string>,
-  InputMethod extends CaseInsensitiveMethod = "get",
-  M extends Method = Lowercase<InputMethod>,
+  InputMethod extends CaseInsensitive<keyof E[CandidatePaths] & string> &
+    CaseInsensitiveMethod = CaseInsensitive<keyof E[CandidatePaths] & string> &
+    CaseInsensitiveMethod,
+  M extends Method = CaseInsensitive<"get"> extends InputMethod
+    ? "get"
+    : Lowercase<InputMethod>,
   Query extends ApiP<E, CandidatePaths, M, "query"> = ApiP<
     E,
     CandidatePaths,
@@ -76,19 +85,11 @@ type FetchT<UrlPrefix extends UrlPrefixPattern, E extends ApiEndpoints> = <
     : Record<StatusCode, never>,
 >(
   input: Input,
-  init: ApiHasP<E, CandidatePaths, M> extends true
-    ? RequestInitT<
-        InputMethod,
-        ApiP<E, CandidatePaths, M, "body">,
-        ApiP<E, CandidatePaths, M, "headers">
-      >
-    :
-        | RequestInitT<
-            InputMethod,
-            ApiP<E, CandidatePaths, M, "body">,
-            ApiP<E, CandidatePaths, M, "headers">
-          >
-        | undefined,
+  init: RequestInitT<
+    InputMethod,
+    ApiP<E, CandidatePaths, M, "body">,
+    ApiP<E, CandidatePaths, M, "headers">
+  >,
 ) => Promise<ResBody>;
 
 export default FetchT;