fix: Make Mentoss work in Bun (#36)

* fix: Make Mentoss work in Bun

* Fix delay test

Author: nzakas

src/fetch-mocker.js

@@ -190,7 +190,23 @@ export class FetchMocker {
 			const request = new this.#Request(fixedInput, init);
 			let useCors = false;
 			let preflightData;
-
+			
+			/*
+			 * Bun's fetch implementation sets credentials to "include" by default
+			 * and doesn't allow overwriting that value when creating a Request.
+			 * We therefore need to hack it together to make sure this works in
+			 * Bun correctly.
+			 * https://github.com/oven-sh/bun/issues/17052
+			 */
+			if ("Bun" in globalThis) {
+				Object.defineProperty(request, "credentials", {
+					configurable: true,
+					enumerable: true,
+					value: init?.credentials ?? "same-origin",
+					writable: false,
+				});
+			}
+			
 			if (request.credentials === "include") {
 				throw new Error("Credentialed requests are not yet supported.");
 			}

tests/fetch-mocker.test.js

@@ -532,10 +532,7 @@ describe("FetchMocker", () => {
 			const server = new MockServer(BASE_URL);
 			const fetchMocker = new FetchMocker({ servers: [server] });
 
-			await assert.rejects(fetchMocker.fetch("/hello"), {
-				name: "TypeError",
-				message: "Failed to parse URL from /hello",
-			});
+			await assert.rejects(fetchMocker.fetch("/hello"), /Failed [\w\W]+\/hello/iu);
 		});
 
 		it("should return 200 when using a relative URL and a baseUrl", async () => {

tests/mock-server.test.js

@@ -44,6 +44,7 @@ function createRequest({ method, url, headers = {}, body = undefined }) {
 			requestInit.body = JSON.stringify(body);
 			requestInit.headers["content-type"] = "application/json";
 		} else {
+			requestInit.headers["content-type"] = "text/plain;charset=UTF-8";
 			requestInit.body = body;
 		}
 	}
@@ -260,8 +261,9 @@ describe("MockServer", () => {
 			const response = await server.receive(request);
 			const elapsed = Date.now() - startTime;
 
+			// Note: Bun's clock runs fast so could be a bit under 500ms
 			assert.ok(
-				elapsed >= 500,
+				elapsed >= 475,
 				`Response was delayed ${elapsed}ms, expected at least 500ms.`,
 			);
 			assert.strictEqual(response.url, `${BASE_URL}/test?foo=bar`);