add test to make sure HttpGetter supports compression

commafeed-server/src/test/java/com/commafeed/backend/HttpGetterTest.java

@@ -174,6 +174,23 @@ class HttpGetterTest {
 		Assertions.assertEquals(2, calls.get());
 	}
 
+	@Test
+	void supportsCompression() {
+		this.mockServerClient.when(HttpRequest.request().withMethod("GET")).respond(req -> {
+			String acceptEncodingHeader = req.getFirstHeader(HttpHeaders.ACCEPT_ENCODING);
+			if (!acceptEncodingHeader.contains("deflate")) {
+				throw new Exception("deflate should be in the Accept-Encoding header");
+			}
+			if (!acceptEncodingHeader.contains("gzip")) {
+				throw new Exception("gzip should be in the Accept-Encoding header");
+			}
+
+			return HttpResponse.response().withBody("ok");
+		});
+
+		Assertions.assertDoesNotThrow(() -> getter.getBinary(this.feedUrl, TIMEOUT));
+	}
+
 	@Test
 	void largeFeedWithContentLengthHeader() {
 		byte[] bytes = new byte[(int) DataSize.kilobytes(100).toBytes()];