Fix undici response parsing when status code says no content but there is content

packages/testcontainers/src/wait-strategies/http-wait-strategy.ts

@@ -1,8 +1,9 @@
 import Dockerode from "dockerode";
-import { Agent, Dispatcher, request } from "undici";
+import { Agent, request } from "undici";
 import { IntervalRetry, log } from "../common";
 import { getContainerRuntimeClient } from "../container-runtime";
 import { BoundPorts } from "../utils/bound-ports";
+import { undiciResponseToFetchResponse } from "./utils/undici-response-parser";
 import { AbstractWaitStrategy } from "./wait-strategy";
 
 export interface HttpWaitStrategyOptions {
@@ -95,7 +96,7 @@ export class HttpWaitStrategy extends AbstractWaitStrategy {
             }
           }
 
-          return this.undiciResponseToFetchResponse(
+          return undiciResponseToFetchResponse(
             await request(url, {
               method: this.method,
               signal: AbortSignal.timeout(this.readTimeoutMs),
@@ -164,31 +165,6 @@ export class HttpWaitStrategy extends AbstractWaitStrategy {
     throw new Error(message);
   }
 
-  /**
-   * Converts an undici response to a fetch response.
-   * This is necessary because node's fetch does not support disabling SSL validation (https://github.com/orgs/nodejs/discussions/44038).
-   *
-   * @param undiciResponse The undici response to convert.
-   * @returns The fetch response.
-   */
-  private undiciResponseToFetchResponse(undiciResponse: Dispatcher.ResponseData): Response {
-    const headers = new Headers();
-    for (const [key, value] of Object.entries(undiciResponse.headers)) {
-      if (Array.isArray(value)) {
-        for (const v of value) {
-          headers.append(key, v);
-        }
-      } else if (value !== undefined) {
-        headers.set(key, value);
-      }
-    }
-
-    return new Response(undiciResponse.body, {
-      status: undiciResponse.statusCode,
-      headers,
-    });
-  }
-
   private getAgent(): Agent | undefined {
     if (this._allowInsecure) {
       return new Agent({

packages/testcontainers/src/wait-strategies/utils/undici-response-parser.test.ts

@@ -0,0 +1,59 @@
+import { Readable } from "stream";
+import { Dispatcher } from "undici";
+import BodyReadable from "undici/types/readable";
+import { undiciResponseToFetchResponse } from "./undici-response-parser";
+
+test("converts undici response to fetch response", async () => {
+  const responseData: Partial<Dispatcher.ResponseData> = {
+    statusCode: 200,
+    headers: { "content-type": "application/json" },
+    body: createBody('{"key":"value"}'),
+  };
+
+  const response = undiciResponseToFetchResponse(responseData as Dispatcher.ResponseData);
+
+  expect(response.status).toBe(200);
+  expect(response.headers.get("content-type")).toBe("application/json");
+  await expect(response.text()).resolves.toBe('{"key":"value"}');
+});
+
+test("handles empty headers", async () => {
+  const responseData: Partial<Dispatcher.ResponseData> = {
+    statusCode: 200,
+    body: createBody(),
+  };
+
+  const response = undiciResponseToFetchResponse(responseData as Dispatcher.ResponseData);
+
+  expect(response.headers).toEqual(new Headers());
+});
+
+test("handles a header array", async () => {
+  const responseData: Partial<Dispatcher.ResponseData> = {
+    statusCode: 200,
+    headers: {
+      "x-multiple-values": ["value1", "value2"],
+    },
+    body: createBody(),
+  };
+
+  const response = undiciResponseToFetchResponse(responseData as Dispatcher.ResponseData);
+
+  expect(response.headers.get("x-multiple-values")).toBe("value1, value2");
+});
+
+test.each([204, 205, 304])("sets body to null for %i status code", async (statusCode) => {
+  const responseData: Partial<Dispatcher.ResponseData> = {
+    statusCode: statusCode,
+    headers: { "content-type": "application/json" },
+    body: createBody('{"key":"value"}'),
+  };
+
+  const response = undiciResponseToFetchResponse(responseData as Dispatcher.ResponseData);
+
+  await expect(response.text()).resolves.toBe("");
+});
+
+function createBody(str: string = ""): BodyReadable {
+  return Readable.from(Buffer.from(str, "utf-8")) as Dispatcher.ResponseData["body"];
+}

packages/testcontainers/src/wait-strategies/utils/undici-response-parser.ts

@@ -0,0 +1,30 @@
+import { Readable } from "stream";
+import { Dispatcher } from "undici";
+
+/**
+ * Converts an undici response to a fetch response.
+ * This is necessary because node's fetch does not support disabling SSL validation (https://github.com/orgs/nodejs/discussions/44038).
+ *
+ * @param undiciResponse The undici response to convert.
+ * @returns The fetch response.
+ */
+export function undiciResponseToFetchResponse(undiciResponse: Dispatcher.ResponseData): Response {
+  const headers = new Headers();
+  if (undiciResponse.headers) {
+    for (const [key, value] of Object.entries(undiciResponse.headers)) {
+      if (Array.isArray(value)) {
+        for (const v of value) {
+          headers.append(key, v);
+        }
+      } else if (value !== undefined) {
+        headers.set(key, value);
+      }
+    }
+  }
+
+  const status = undiciResponse.statusCode;
+  const hasNullBody = status === 204 || status === 205 || status === 304;
+  const responseBody = hasNullBody ? null : Readable.toWeb(undiciResponse.body);
+
+  return new Response(responseBody, { status, headers });
+}