fix(http1.1): compute Content-Length as a utf8 byte length

src/targets/http/http1.1/client.test.ts

@@ -0,0 +1,24 @@
+import { HTTPSnippet, Request } from '../../../httpsnippet';
+
+const unicodeRequest = {
+  method: 'POST',
+  url: 'http://mockbin.com/har',
+  headers: [
+    {
+      name: 'content-type',
+      value: 'text/plain',
+    },
+  ],
+  postData: {
+    mimeType: 'text/plain',
+    text: 'äöü',
+  },
+} as Request;
+
+describe('http:http1.1', () => {
+  it('should set Content-Length to the byte length of a non-ascii body', () => {
+    const result = String(new HTTPSnippet(unicodeRequest).convert('http', 'http1.1'));
+
+    expect(result).toContain('Content-Length: 6');
+  });
+});

src/targets/http/http1.1/client.ts

@@ -69,7 +69,7 @@ export const http11: Client<Http11Options> = {
     // RFC 7230 Section 3.3.3. Message Body Length
     // Automatically set Content-Length header if option is on, postData is present and no header already exists.
     if (opts.autoContentLength && postData.text && !headerKeys.includes('content-length')) {
-      const length = Buffer.byteLength(postData.text, 'ascii').toString();
+      const length = Buffer.byteLength(postData.text, 'utf8').toString();
       push(`Content-Length: ${length}`);
     }