maxBytes param for bytes() func. tests updated

Author: makoni

Sources/AsyncHTTPClient/AsyncAwait/HTTPClientResponse.swift

@@ -141,9 +141,11 @@ extension HTTPClientResponse {
 @available(macOS 10.15, iOS 13.0, watchOS 6.0, tvOS 13.0, *)
 extension HTTPClientResponse {
     /// Response body as `ByteBuffer`.
+    /// - Parameter maxBytes: The maximum number of bytes this method is allowed to accumulate. 
+    /// Will accumulate all available bytes if nil passed.
     /// - Returns: Bytes collected over time
-    public func bytes() async throws -> ByteBuffer {
-        if let expectedBytes = self.headers.first(name: "content-length").flatMap(Int.init) {
+    public func bytes(upTo maxBytes: Int? = nil) async throws -> ByteBuffer {
+        if let expectedBytes = maxBytes ?? self.headers.first(name: "content-length").flatMap(Int.init) {
             return try await self.body.collect(upTo: expectedBytes)
         }
 

Tests/AsyncHTTPClientTests/AsyncAwaitEndToEndTests.swift

@@ -852,9 +852,18 @@ final class AsyncAwaitEndToEndTests: XCTestCase {
             ) else { return }
             XCTAssertEqual(response.headers["content-length"], ["4"])
             guard let body = await XCTAssertNoThrowWithResult(
-                try await response.bytes()
+                try await response.bytes(upTo: 4)
             ) else { return }
             XCTAssertEqual(body, ByteBuffer(string: "1234"))
+
+            guard var responseNoContentLength = await XCTAssertNoThrowWithResult(
+                try await client.execute(request, deadline: .now() + .seconds(10), logger: logger)
+            ) else { return }
+            responseNoContentLength.headers.remove(name: "content-length")
+            guard let body2 = await XCTAssertNoThrowWithResult(
+                try await responseNoContentLength.bytes()
+            ) else { return }
+            XCTAssertEqual(body2, ByteBuffer(string: "1234"))
         }
     }