fix: [http] Consume unread body and trailers before reading next request (#3990)

- Added `ServerRequest.finalize()`:  consuming all unread body stream and trailers.
  - This is cleanup method for reading next request from same keep-alive connection.
  - Needed when handler didn't consume all body and trailers even after responding.
- refactor: `ServerRequest._bodyStream()`, `ServerRequestBody` are removed.
  - Now using `bodyReader()` and `chunkedBodyReader()` instead.
- fix: Trailers should only be read `transfer-encoding` is `chunked` and `trailer` header is set and its value is valid.
- fix: use `Headers.append()` on reading trailers.
- fix: delete `trailer` field from headers after reading trailers.
- reorg: Several functions related to IO are moved into `http/io.ts`

1 files changed, 29 insertions, 15 deletions

diff --git a/std/http/racing_server_test.ts b/std/http/racing_server_test.ts
index 639935339..07df92bae 100644
--- a/std/http/racing_server_test.ts
+++ b/std/http/racing_server_test.ts
@@ -1,7 +1,7 @@
 const { connect, run } = Deno;
 
 import { assert, assertEquals } from "../testing/asserts.ts";
-import { BufReader } from "../io/bufio.ts";
+import { BufReader, BufWriter } from "../io/bufio.ts";
 import { TextProtoReader } from "../textproto/mod.ts";
 
 let server: Deno.Process;
@@ -21,20 +21,20 @@ function killServer(): void {
   server.stdout?.close();
 }
 
-const input = `GET / HTTP/1.1
-
-GET / HTTP/1.1
-
-GET / HTTP/1.1
-
-GET / HTTP/1.1
-
-`;
+const input = [
+  "GET / HTTP/1.1\r\n\r\n",
+  "GET / HTTP/1.1\r\n\r\n",
+  "GET / HTTP/1.1\r\n\r\n",
+  "POST / HTTP/1.1\r\ncontent-length: 4\r\n\r\ndeno",
+  "POST / HTTP/1.1\r\ntransfer-encoding: chunked\r\n\r\n4\r\ndeno\r\n0\r\n\r\n",
+  "POST / HTTP/1.1\r\ntransfer-encoding: chunked\r\ntrailer: deno\r\n\r\n4\r\ndeno\r\n0\r\n\r\ndeno: land\r\n\r\n",
+  "GET / HTTP/1.1\r\n\r\n"
+].join("");
 const HUGE_BODY_SIZE = 1024 * 1024;
 const output = `HTTP/1.1 200 OK
-content-length: 8
+content-length: 6
 
-Hello 1
+Step1
 HTTP/1.1 200 OK
 content-length: ${HUGE_BODY_SIZE}
 
@@ -42,9 +42,21 @@ ${"a".repeat(HUGE_BODY_SIZE)}HTTP/1.1 200 OK
 content-length: ${HUGE_BODY_SIZE}
 
 ${"b".repeat(HUGE_BODY_SIZE)}HTTP/1.1 200 OK
-content-length: 8
+content-length: 6
+
+Step4
+HTTP/1.1 200 OK
+content-length: 6
+
+Step5
+HTTP/1.1 200 OK
+content-length: 6
+
+Step6
+HTTP/1.1 200 OK
+content-length: 6
 
-World 4
+Step7
 `;
 
 Deno.test(async function serverPipelineRace(): Promise<void> {
@@ -52,7 +64,9 @@ Deno.test(async function serverPipelineRace(): Promise<void> {
 
   const conn = await connect({ port: 4501 });
   const r = new TextProtoReader(new BufReader(conn));
-  await conn.write(new TextEncoder().encode(input));
+  const w = new BufWriter(conn);
+  await w.write(new TextEncoder().encode(input));
+  await w.flush();
   const outLines = output.split("\n");
   // length - 1 to disregard last empty line
   for (let i = 0; i < outLines.length - 1; i++) {