Use native Node.js fetch

Since Node.js 17.5, Node.js has had native `fetch` support. This means
we can no longer support Node.js 16.

Author: erbridge

.github/workflows/test.yml

@@ -6,7 +6,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        version: [16, 18, latest]
+        version: [18, latest]
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3

jest.config.js

@@ -1,4 +1,5 @@
 /** @type {import('jest').Config} */
 export default {
   transform: {},
+  setupFiles: ["./jest.setup.js"],
 };

jest.setup.js

@@ -0,0 +1,3 @@
+import fetchMock from "jest-fetch-mock";
+
+fetchMock.enableMocks();

lib/Model.test.js

@@ -1,16 +1,8 @@
 import { jest } from "@jest/globals";
-import { FetchError, Response } from "node-fetch";
-
-jest.unstable_mockModule("node-fetch", () => ({
-  default: jest.fn(),
-  FetchError,
-}));
-
 import { ReplicateResponseError } from "./errors.js";
 import Model from "./Model.js";
 import Prediction, { PredictionStatus } from "./Prediction.js";
-
-const { default: ReplicateClient } = await import("./ReplicateClient.js");
+import ReplicateClient from "./ReplicateClient.js";
 
 let client;
 let model;
@@ -212,22 +204,16 @@ describe("predict()", () => {
 
     const predictionLoadResults = [
       () => {
-        throw new ReplicateResponseError(
-          "test error",
-          new Response("{}", {
-            status: 500,
-            statusText: "Internal Server Error",
-          })
-        );
+        throw new ReplicateResponseError("test error", {
+          status: 500,
+          statusText: "Internal Server Error",
+        });
       },
       () => {
-        throw new ReplicateResponseError(
-          "test error",
-          new Response("{}", {
-            status: 429,
-            statusText: "Too Many Requests",
-          })
-        );
+        throw new ReplicateResponseError("test error", {
+          status: 429,
+          statusText: "Too Many Requests",
+        });
       },
       () =>
         new Prediction(

lib/Prediction.test.js

@@ -1,13 +1,6 @@
 import { jest } from "@jest/globals";
-import { FetchError } from "node-fetch";
 import Prediction, { PredictionStatus } from "./Prediction.js";
-
-jest.unstable_mockModule("node-fetch", () => ({
-  default: jest.fn(),
-  FetchError,
-}));
-
-const { default: ReplicateClient } = await import("./ReplicateClient.js");
+import ReplicateClient from "./ReplicateClient.js";
 
 let client;
 let prediction;

lib/ReplicateClient.js

@@ -1,4 +1,3 @@
-import fetch, { FetchError } from "node-fetch";
 import pkg from "../package.json" assert { type: "json" };
 import {
   ReplicateError,
@@ -111,11 +110,7 @@ export default class ReplicateClient {
     try {
       resp = await fetch(url, requestInit);
     } catch (err) {
-      if (!err instanceof FetchError) {
-        throw err;
-      }
-
-      throw new ReplicateRequestError(url, requestInit);
+      throw new ReplicateRequestError(url, requestInit, err);
     }
 
     const respText = await resp.text();

lib/ReplicateClient.test.js

@@ -1,21 +1,12 @@
 import { jest } from "@jest/globals";
-import { FetchError, Response } from "node-fetch";
-
-jest.unstable_mockModule("node-fetch", () => ({
-  default: jest.fn(),
-  FetchError,
-}));
-
 import {
   ReplicateError,
   ReplicateRequestError,
   ReplicateResponseError,
 } from "./errors.js";
 import Model from "./Model.js";
 import Prediction from "./Prediction.js";
-
-const { default: fetch } = await import("node-fetch");
-const { default: ReplicateClient } = await import("./ReplicateClient.js");
+import ReplicateClient from "./ReplicateClient.js";
 
 let client;
 
@@ -170,7 +161,7 @@ describe("prediction()", () => {
 describe("request()", () => {
   it("throws ReplicateRequestError on failed fetch", async () => {
     fetch.mockImplementation(async () => {
-      throw new FetchError("Something went wrong");
+      throw new Error("Something went wrong");
     });
 
     await expect(
@@ -179,18 +170,15 @@ describe("request()", () => {
     await expect(
       async () => await client.request("GET /v1/predictions/testprediction")
     ).rejects.toThrowError(
-      "Failed to make request: method=GET, url=https://api.replicate.com/v1/predictions/testprediction, body=undefined"
+      "Failed to make request: method=GET, url=https://api.replicate.com/v1/predictions/testprediction, body=undefined, error=Error: Something went wrong"
     );
   });
 
   it("throws ReplicateResponseError on error status", async () => {
-    fetch.mockImplementation(
-      async () =>
-        new Response('{"status":403,"details":"Something went wrong"}', {
-          status: 403,
-          statusText: "Unauthorized",
-        })
-    );
+    fetch.mockResponse('{"status":403,"details":"Something went wrong"}', {
+      status: 403,
+      statusText: "Unauthorized",
+    });
 
     await expect(
       async () => await client.request("GET /v1/predictions/testprediction")

lib/errors.js

@@ -4,9 +4,9 @@ export class ReplicateRequestError extends ReplicateError {
   method;
   body;
 
-  constructor(url, requestInit) {
+  constructor(url, requestInit, err) {
     super(
-      `Failed to make request: method=${requestInit.method}, url=${url}, body=${requestInit.body}`
+      `Failed to make request: method=${requestInit.method}, url=${url}, body=${requestInit.body}, error=${err}`
     );
 
     this.method = requestInit.method;