finagle-mux: Add API for Request Which Only Needs the Body

Problem / Solution

When testing functionality via the Mux protocol, if only testing the
internal mechanics of how clients and servers interact, specifying a
`Path` for a mux `Request` to use is unnecessary and adds to extra code
to write and maintain. This change provides the ability to create a mux
`Request` in both Scala and Java without specifying a `Path` explicitly.
In those cases `Path.empty` will be used.

Differential Revision: https://phabricator.twitter.biz/D613686

CHANGELOG.rst

@@ -20,6 +20,10 @@ New Features
   Tying a `Name` directly to a `Service` can be extremely useful for testing the functionality
   of a Finagle client. ``PHAB_ID=D605745``
 
+* finagle-mux: Added variant of `c.t.f.mux.Request.apply` and `c.t.f.mux.Requests.make` which takes
+  only the body of the `Request` (in the form of `c.t.io.Buf`) as a parameter. This is useful for
+  when the path value of a `Request` is not used by the server (e.g. testing). ``PHAB_ID=D613686``
+
 Runtime Behavior Changes
 ~~~~~~~~~~~~~~~~~~~~~~~~
 

finagle-mux/src/main/scala/com/twitter/finagle/mux/Request.scala

@@ -24,6 +24,12 @@ object Request {
 
   val empty: Request = Impl(Path.empty, Nil, Buf.Empty)
 
+  /**
+   * Variant to create a [[Request]] which only requires a 'payload' (i.e. [[Request]] 'body'). This
+   * version should likely only be used when testing.
+   */
+  def apply(payload: Buf): Request = apply(Path.empty, Nil, payload)
+
   def apply(dst: Path, payload: Buf): Request = apply(dst, Nil, payload)
 
   def apply(dst: Path, ctxts: Seq[(Buf, Buf)], payload: Buf): Request = Impl(dst, ctxts, payload)
@@ -33,6 +39,12 @@ object Request {
 object Requests {
   val empty: Request = Request.empty
 
+  /**
+   * Variant to create a [[Request]] which only requires a 'payload' (i.e. [[Request]] 'body'). This
+   * version should likely only be used when testing.
+   */
+  def make(payload: Buf): Request = make(Path.empty, Nil, payload)
+
   def make(dst: Path, payload: Buf): Request = make(dst, Nil, payload)
 
   def make(dst: Path, contexts: Seq[(Buf, Buf)], payload: Buf): Request =

finagle-mux/src/test/java/com/twitter/finagle/mux/RequestsCompilationTest.java

@@ -0,0 +1,17 @@
+package com.twitter.finagle.mux;
+
+import org.junit.Test;
+
+import com.twitter.io.Buf;
+import com.twitter.io.Bufs;
+
+public class RequestsCompilationTest {
+
+  private Buf buf = Bufs.EMPTY;
+
+  @Test
+  public void makeWithPayload() {
+    Request request = Requests.make(buf);
+  }
+
+}

finagle-mux/src/test/scala/com/twitter/finagle/mux/RequestTest.scala

@@ -0,0 +1,17 @@
+package com.twitter.finagle.mux
+
+import com.twitter.finagle.Path
+import com.twitter.io.Buf
+import org.scalatest.FunSuite
+
+class RequestTest extends FunSuite {
+
+  test("create request with payload") {
+    val buf = Buf.Utf8("Hello")
+    val request = Request(buf)
+    assert(request.destination == Path.empty)
+    assert(request.contexts == Nil)
+    assert(request.body == buf)
+  }
+
+}