Use early init for fetcher

Author: Denis-Averin

Makefile

@@ -31,7 +31,11 @@ npm-test:
 	npm test
 
 .PHONY: test
-test: npm-test example snippets
+test: typecheck npm-test example snippets
+
+.PHONY: typecheck
+typecheck:
+	npm run typecheck
 
 .PHONY: cover
 cover:

README.md

@@ -59,7 +59,7 @@ const config = new Barcode.Configuration(
 
 async function generateBarcode(api) {
     const request = new Barcode.GenerateRequestWrapper(
-        Barcode.EncodeBarcodeType.Qr, 
+        Barcode.EncodeBarcodeType.Qr,
         'Aspose.BarCode for Cloud Sample');
 
     const oneBarcode = await api.generate(request);

package.json

@@ -133,6 +133,7 @@
   },
   "scripts": {
     "test": "npx jest",
+    "typecheck": "npx tsc --noEmit",
     "cover": "npx jest --coverage",
     "lint": "npx eslint src test snippets",
     "format": "npx eslint src test snippets eslint.config.mjs --fix",

src/JWTAuth.ts

@@ -2,25 +2,6 @@ import { Configuration } from './Configuration';
 import { Authentication } from './Authentication';
 import { ApiErrorResponse } from './models';
 
-type StringMap = Record<string, string>;
-
-interface FetchHeaders {
-    forEach(callback: (value: string, key: string) => void): void;
-}
-
-interface FetchResponse {
-    status: number;
-    statusText: string;
-    headers: FetchHeaders;
-    ok: boolean;
-    text(): Promise<string>;
-}
-
-type Fetcher = (
-    input: string | URL,
-    init?: { method?: string; headers?: StringMap; body?: any }
-) => Promise<FetchResponse>;
-
 type AuthResponse = {
     statusCode: number;
     statusMessage: string;
@@ -37,9 +18,16 @@ type AuthRejectType = {
 export class JWTAuth implements Authentication {
     private _accessToken?: string;
     private readonly _configuration: Configuration;
+    private readonly _fetcher: typeof fetch;
 
     constructor(configuration: Configuration) {
         this._configuration = configuration;
+        const resolvedFetch = (globalThis as { fetch?: typeof fetch }).fetch;
+        if (!resolvedFetch) {
+            throw new Error('Global fetch API is not available. Please use Node.js 18+.');
+        }
+
+        this._fetcher = resolvedFetch;
 
         if (configuration.accessToken) {
             // Use saved token
@@ -69,15 +57,14 @@ export class JWTAuth implements Authentication {
         if (!this._configuration.clientId || !this._configuration.clientSecret) {
             throw new Error("Required 'clientId' or 'clientSecret' not specified in configuration.");
         }
-        const fetcher = this.getFetch();
         const requestBody = new URLSearchParams({
             grant_type: 'client_credentials',
             client_id: this._configuration.clientId,
             client_secret: this._configuration.clientSecret,
         }).toString();
-        let response: FetchResponse;
+        let response: Response;
         try {
-            response = await fetcher(this._configuration.tokenUrl, {
+            response = await this._fetcher(this._configuration.tokenUrl, {
                 method: 'POST',
                 headers: {
                     'Content-Type': 'application/x-www-form-urlencoded',
@@ -125,7 +112,7 @@ export class JWTAuth implements Authentication {
         return parsed.access_token;
     }
 
-    private toHeaderDict(headers: FetchHeaders): NodeJS.Dict<string | string[]> {
+    private toHeaderDict(headers: Headers): NodeJS.Dict<string | string[]> {
         const normalizedHeaders: NodeJS.Dict<string | string[]> = {};
 
         headers.forEach((value, key) => {
@@ -147,15 +134,6 @@ export class JWTAuth implements Authentication {
         return normalizedHeaders;
     }
 
-    private getFetch(): Fetcher {
-        const fetcher = (globalThis as { fetch?: Fetcher }).fetch;
-        if (!fetcher) {
-            throw new Error('Global fetch API is not available. Please use Node.js 18+.');
-        }
-
-        return fetcher;
-    }
-
     private normalizeFetchError(error: unknown): Error {
         if (error instanceof Error) {
             const mutableError = error as Error & { code?: string; cause?: unknown; name: string };

src/api.ts

@@ -67,27 +67,18 @@ type ApiRejectType = {
     error: Error;
 };
 
-interface FetchHeaders {
-    forEach(callback: (value: string, key: string) => void): void;
-}
-
-interface FetchResponse {
-    status: number;
-    statusText: string;
-    headers: FetchHeaders;
-    ok: boolean;
-    arrayBuffer(): Promise<ArrayBuffer>;
-}
+export class ApiClient {
+    private readonly _fetcher: typeof fetch;
 
-interface FetchOptions {
-    method?: string;
-    headers?: StringMap;
-    body?: any;
-}
+    constructor() {
+        const resolvedFetch = (globalThis as { fetch?: typeof fetch }).fetch;
+        if (!resolvedFetch) {
+            throw new Error('Global fetch API is not available. Please use Node.js 18+.');
+        }
 
-type Fetcher = (input: string | URL, options?: FetchOptions) => Promise<FetchResponse>;
+        this._fetcher = resolvedFetch;
+    }
 
-export class ApiClient {
     public requestAsync(options: ApiRequestOptions): Promise<ApiResult> {
         const url: URL = options.qs
             ? new URL(`?${new URLSearchParams(options.qs).toString()}`, options.uri)
@@ -97,7 +88,7 @@ export class ApiClient {
 
         const responseEncoding: BufferEncoding | null = options.encoding === null ? null : options.encoding || 'utf-8';
 
-        const requestOptions: FetchOptions = {
+        const requestOptions: RequestInit = {
             method: options.method || 'GET',
             headers: options.headers,
         };
@@ -136,13 +127,12 @@ export class ApiClient {
 
     private async doFetchRequest(
         url: URL,
-        requestOptions: FetchOptions,
+        requestOptions: RequestInit,
         responseEncoding: BufferEncoding | null
     ): Promise<ApiResult> {
-        const fetcher = this.getFetch();
-        let response: FetchResponse;
+        let response: Response;
         try {
-            response = await fetcher(url.toString(), requestOptions);
+            response = await this._fetcher(url.toString(), requestOptions);
         } catch (error) {
             return Promise.reject({
                 response: null,
@@ -188,7 +178,7 @@ export class ApiClient {
     }
 
     private async readResponseBody(
-        response: FetchResponse,
+        response: Response,
         responseEncoding: BufferEncoding | null
     ): Promise<string | Buffer> {
         const arrayBuffer = await response.arrayBuffer();
@@ -201,7 +191,7 @@ export class ApiClient {
         return buffer.toString(responseEncoding);
     }
 
-    private toHeaderDict(headers: FetchHeaders): NodeJS.Dict<string | string[]> {
+    private toHeaderDict(headers: Headers): NodeJS.Dict<string | string[]> {
         const normalizedHeaders: NodeJS.Dict<string | string[]> = {};
 
         headers.forEach((value, key) => {
@@ -223,15 +213,6 @@ export class ApiClient {
         return normalizedHeaders;
     }
 
-    private getFetch(): Fetcher {
-        const fetcher = (globalThis as { fetch?: Fetcher }).fetch;
-        if (!fetcher) {
-            throw new Error('Global fetch API is not available. Please use Node.js 18+.');
-        }
-
-        return fetcher;
-    }
-
     private normalizeFetchError(error: unknown): Error {
         if (error instanceof Error) {
             const mutableError = error as Error & { code?: string; cause?: unknown; name: string };