Replace axios with (node-)fetch

package.json

@@ -22,7 +22,7 @@
   "jsnext:main": "dist/mollie.esm.js",
   "types": "dist/types/src/types.d.ts",
   "engines": {
-    "node": ">=14"
+    "node": ">=8"
   },
   "scripts": {
     "prepublish": "yarn build",
@@ -41,7 +41,7 @@
     "lint": "yarn lint:eslint:fix && yarn lint:prettier"
   },
   "dependencies": {
-    "axios": "^1.6.2",
+    "node-fetch": "^2.7.0",
     "ruply": "^1.0.1"
   },
   "devDependencies": {
@@ -51,7 +51,7 @@
     "@mollie/eslint-config-typescript": "^1.6.5",
     "@types/jest": "^29.5.11",
     "@types/node": "^18.14.6",
-    "axios-mock-adapter": "1.19.0",
+    "@types/node-fetch": "^2.6.11",
     "babel-jest": "^29.5.0",
     "commitizen": "^4.3.0",
     "cz-conventional-changelog": "^3.3.0",

src/Options.ts

@@ -1,5 +1,3 @@
-import { type AxiosRequestConfig } from 'axios';
-
 import type Xor from './types/Xor';
 
 type Options = Xor<
@@ -29,7 +27,7 @@ type Options = Xor<
    * The URL of the root of the Mollie API. Default: `'https://api.mollie.com:443/v2/'`.
    */
   apiEndpoint?: string;
-} & Pick<AxiosRequestConfig, 'adapter' | 'proxy' | 'socketPath' | 'timeout'>;
+};
 
 const falsyDescriptions = new Map<any, string>([
   [undefined, 'undefined'],
@@ -46,7 +44,7 @@ function describeFalsyOption(options: Options, key: keyof Options) {
     return null;
   }
   return `Parameter "${key}" is ${falsyDescriptions.get(options[key]) ?? options[key]}.`;
-};
+}
 
 /**
  * Throws a `TypeError` if the passed options object does not contain an `apiKey` or an `accessToken`.

src/binders/profiles/giftcardIssuers/ProfileGiftcardIssuersBinder.ts

@@ -1,5 +1,5 @@
 import type TransformingNetworkClient from '../../../communication/TransformingNetworkClient';
-import {type IssuerData} from '../../../data/issuer/IssuerModel';
+import { type IssuerData } from '../../../data/issuer/IssuerModel';
 import type IssuerModel from '../../../data/issuer/IssuerModel';
 import ApiError from '../../../errors/ApiError';
 import renege from '../../../plumbing/renege';

src/communication/NetworkClient.ts

@@ -1,12 +1,12 @@
 import https from 'https';
+import fetch, { type RequestInit } from 'node-fetch';
 import { type SecureContextOptions } from 'tls';
 
-import axios, { type AxiosInstance, type AxiosRequestConfig, type AxiosResponse, type RawAxiosRequestHeaders } from 'axios';
-
 import { run } from 'ruply';
 import type Page from '../data/page/Page';
 import ApiError from '../errors/ApiError';
 import type Options from '../Options';
+import fling from '../plumbing/fling';
 import DemandingIterator from '../plumbing/iteration/DemandingIterator';
 import HelpfulIterator from '../plumbing/iteration/HelpfulIterator';
 import Throttler from '../plumbing/Throttler';
@@ -15,8 +15,9 @@ import { type IdempotencyParameter } from '../types/parameters';
 import breakUrl from './breakUrl';
 import buildUrl, { type SearchParameters } from './buildUrl';
 import dromedaryCase from './dromedaryCase';
-import makeRetrying, { idempotencyHeaderName } from './makeRetrying';
-import fling from '../plumbing/fling';
+import { idempotencyHeaderName, ResponseWithIdempotencyKey, retryingFetch } from './makeRetrying';
+// The following line is only necessary for Node.js < 10.0.0, which we only secretly support. Should we ever drop that support completely, we can remove this import.
+import { URL } from 'url';
 
 /**
  * Like `[].map` but with support for non-array inputs, in which case this function behaves as if an array was passed
@@ -69,21 +70,45 @@ const throwApiError = run(
   },
   findProperty =>
     function throwApiError(cause: unknown) {
-      if (findProperty(cause, 'response') && cause.response != undefined) {
-        throw ApiError.createFromResponse(cause.response as AxiosResponse<any>);
-      }
       throw new ApiError(findProperty(cause, 'message') ? String(cause.message) : 'An unknown error has occurred');
     },
 );
 
+/**
+ * Checks whether an API error needs to be thrown based on the passed result.
+ */
+async function processFetchResponse(response: ResponseWithIdempotencyKey) {
+  // Request was successful, but no content was returned.
+  if (response.status == 204) return true;
+  // Request was successful and content was returned.
+  const body = await response.json();
+  if (Math.floor(response.status / 100) == 2) {
+    return body;
+  }
+  // Request was not successful, but the response body contains an error message.
+  if (null != body) {
+    throw ApiError.createFromResponse(body, response.idempotencyKey);
+  }
+  // Request was not successful.
+  throw new ApiError('An unknown error has occurred');
+}
+
 interface Data {}
 interface Context {}
 
 /**
- * This class is essentially a wrapper around axios. It simplifies communication with the Mollie API over the network.
+ * This class is essentially a wrapper around fetch. It simplifies communication with the Mollie API over the network.
  */
 export default class NetworkClient {
-  protected readonly axiosInstance: AxiosInstance;
+  /**
+   * Triggers a request to the Mollie API.
+   *
+   * In contrast to the underlying `fetch` function, this function will:
+   * - retry the request in some scenarios (see `retryingFetch`)
+   * - throw an `ApiError` if the response from the Mollie API indicates an error
+   * - appropriately process the response body before returning it (i.e. parsing it as JSON or throwing an ApiError if the response status indicates an error)
+   */
+  protected readonly request: (pathname: string, options?: RequestInit) => Promise<any>;
   constructor({
     apiKey,
     accessToken,
@@ -92,71 +117,69 @@ export default class NetworkClient {
     caCertificates,
     libraryVersion,
     nodeVersion,
-    ...axiosOptions
   }: Options & { caCertificates?: SecureContextOptions['ca']; libraryVersion: string; nodeVersion: string }) {
-    axiosOptions.headers = { ...axiosOptions.headers };
     // Compose the headers set in the sent requests.
-    axiosOptions.headers['User-Agent'] = composeUserAgent(nodeVersion, libraryVersion, versionStrings);
+    const headers: Record<string, string> = {};
+    headers['User-Agent'] = composeUserAgent(nodeVersion, libraryVersion, versionStrings);
     if (apiKey != undefined) {
-      axiosOptions.headers['Authorization'] = `Bearer ${apiKey}`;
+      headers['Authorization'] = `Bearer ${apiKey}`;
     } /* if (accessToken != undefined) */ else {
-      axiosOptions.headers['Authorization'] = `Bearer ${accessToken}`;
-      axiosOptions.headers['User-Agent'] += ' OAuth/2.0';
+      headers['Authorization'] = `Bearer ${accessToken}`;
+      headers['User-Agent'] += ' OAuth/2.0';
     }
-    axiosOptions.headers['Accept'] = 'application/hal+json';
-    axiosOptions.headers['Accept-Encoding'] = 'gzip';
-    axiosOptions.headers['Content-Type'] = 'application/json';
-    // Create the Axios instance.
-    this.axiosInstance = axios.create({
-      ...axiosOptions,
-      baseURL: apiEndpoint,
-      httpsAgent: new https.Agent({
-        ca: caCertificates,
-      }),
-    });
-    // Make the Axios instance request multiple times is some scenarios.
-    makeRetrying(this.axiosInstance);
+    headers['Accept'] = 'application/hal+json';
+    headers['Accept-Encoding'] = 'gzip';
+    headers['Content-Type'] = 'application/json';
+
+    // Create the https agent.
+    const agent = new https.Agent({ ca: caCertificates });
+
+    // Create retrying fetch function.
+    const fetchWithRetries = retryingFetch(fetch);
+
+    // Create the request function.
+    this.request = (pathname, options) => {
+      const url = new URL(pathname, apiEndpoint);
+      return fetchWithRetries(url, { agent, ...options, headers: { ...headers, ...options?.headers } })
+        .catch(throwApiError)
+        .then(processFetchResponse);
+    };
   }
 
   async post<R>(pathname: string, data: Data & IdempotencyParameter, query?: SearchParameters): Promise<R | true> {
     // Take the idempotency key from the data, if any. It would be cleaner from a design perspective to have the
     // idempotency key in a separate argument instead of cramming it into the data like this. However, having a
     // separate argument would require every endpoint to split the input into those two arguments and thus cause a lot
     // of boiler-plate code.
-    let config: AxiosRequestConfig | undefined = undefined;
-    if (data.idempotencyKey != undefined) {
-      const { idempotencyKey, ...rest } = data;
-      config = { headers: { [idempotencyHeaderName]: idempotencyKey } };
-      data = rest;
-    }
-    const response = await this.axiosInstance.post(buildUrl(pathname, query), data, config).catch(throwApiError);
-    if (response.status == 204) {
-      return true;
-    }
-    return response.data;
+    const { idempotencyKey, ...body } = data;
+    const config: RequestInit = {
+      method: 'POST',
+      headers: idempotencyKey ? { [idempotencyHeaderName]: idempotencyKey } : undefined,
+      body: JSON.stringify(body),
+    };
+    return this.request(buildUrl(pathname, query), config);
   }
 
   async get<R>(pathname: string, query?: SearchParameters): Promise<R> {
-    const response = await this.axiosInstance.get(buildUrl(pathname, query)).catch(throwApiError);
-    return response.data;
+    return this.request(buildUrl(pathname, query));
   }
 
   async list<R>(pathname: string, binderName: string, query?: SearchParameters): Promise<R[]> {
-    const response = await this.axiosInstance.get(buildUrl(pathname, query)).catch(throwApiError);
+    const data = await this.request(buildUrl(pathname, query));
     try {
       /* eslint-disable-next-line no-var */
-      var { _embedded: embedded } = response.data;
+      var { _embedded: embedded } = data;
     } catch (error) {
       throw new ApiError('Received unexpected response from the server');
     }
     return embedded[binderName] as R[];
   }
 
   async page<R>(pathname: string, binderName: string, query?: SearchParameters): Promise<R[] & Pick<Page<R>, 'links' | 'count'>> {
-    const response = await this.axiosInstance.get(buildUrl(pathname, query)).catch(throwApiError);
+    const data = await this.request(buildUrl(pathname, query));
     try {
       /* eslint-disable-next-line no-var */
-      var { _embedded: embedded, _links: links, count } = response.data;
+      var { _embedded: embedded, _links: links, count } = data;
     } catch (error) {
       throw new ApiError('Received unexpected response from the server');
     }
@@ -196,16 +219,16 @@ export default class NetworkClient {
       // and valuesPerMinute is set to 100, all 250 values received values will be yielded before the (two-minute)
       // break.
       const throttler = new Throttler(valuesPerMinute);
-      const { axiosInstance } = this;
+      const { request } = this;
       return new HelpfulIterator<R>(
         (async function* iterate<R>() {
           let url = buildUrl(pathname, { ...query, limit: popLimit() });
           while (true) {
             // Request and parse the page from the Mollie API.
-            const response = await axiosInstance.get(url).catch(throwApiError);
+            const data = await request(url);
             try {
               /* eslint-disable-next-line no-var */
-              var { _embedded: embedded, _links: links } = response.data;
+              var { _embedded: embedded, _links: links } = data;
             } catch (error) {
               throw new ApiError('Received unexpected response from the server');
             }
@@ -230,22 +253,21 @@ export default class NetworkClient {
   }
 
   async patch<R>(pathname: string, data: Data): Promise<R> {
-    const response = await this.axiosInstance.patch(pathname, data).catch(throwApiError);
-    return response.data;
+    const config: RequestInit = {
+      method: 'PATCH',
+      body: JSON.stringify(data),
+    };
+    return this.request(buildUrl(pathname), config);
   }
 
   async delete<R>(pathname: string, context?: Context & IdempotencyParameter): Promise<R | true> {
     // Take the idempotency key from the context, if any.
-    let headers: RawAxiosRequestHeaders | undefined = undefined;
-    if (context?.idempotencyKey != undefined) {
-      const { idempotencyKey, ...rest } = context;
-      headers = { [idempotencyHeaderName]: idempotencyKey };
-      context = rest;
-    }
-    const response = await this.axiosInstance.delete(pathname, { data: context, headers }).catch(throwApiError);
-    if (response.status == 204) {
-      return true;
-    }
-    return response.data as R;
+    const { idempotencyKey, ...body } = context ?? {};
+    const config: RequestInit = {
+      method: 'DELETE',
+      headers: idempotencyKey ? { [idempotencyHeaderName]: idempotencyKey } : undefined,
+      body: JSON.stringify(body),
+    };
+    return this.request(buildUrl(pathname), config);
   }
 }

src/communication/breakUrl.ts

@@ -1,4 +1,4 @@
-// If support for Node.js < 10.0.0 is ever dropped, this import can be removed.
+// The following line is only necessary for Node.js < 10.0.0, which we only secretly support. Should we ever drop that support completely, we can remove this import.
 import { URL } from 'url';
 
 import buildFromEntries from '../plumbing/buildFromEntries';

src/communication/buildUrl.ts

@@ -1,4 +1,4 @@
-// If support for Node.js < 10.0.0 is ever dropped, this import can be removed.
+// The following line is only necessary for Node.js < 10.0.0, which we only secretly support. Should we ever drop that support completely, we can remove this import.
 import { URLSearchParams } from 'url';
 
 import { apply, runIf } from 'ruply';