Multiplexer tests for payload-based stream channels (apple#225)

Motivation:

As part of apple#214 we added a stream channel which deals with
`HTTP2Frame.FramePayload` as well as the relevant entry points in
`HTTP2StreamMultiplexer` to create these streams. We didn't add a
corresponding set of tests.

Modifications:

- Duplicate `HTTP2StreamMultiplexerTests`
- Refactor to make use of new stream creation function and new inbound
  stream initializer
- Fix up a couple of bugs in `HTTP2StreamMultiplexer`:
  - activate pending streams on `channelActive`
  - deactivate pending streams on `channelInactive`
  - change stream writability for pending streams on `channelWritabilityChanged`
  - add implementation for `childChannelClosed(channelID:)`

Result:

- Tests for payload-based stream creation via `HTTP2StreamMultiplexer`

Sources/NIOHTTP2/HTTP2StreamMultiplexer.swift

@@ -72,7 +72,7 @@ public final class HTTP2StreamMultiplexer: ChannelInboundHandler, ChannelOutboun
             return
         }
 
-        if let channel = streams[streamID] {
+        if let channel = self.streams[streamID] {
             channel.receiveInboundFrame(frame)
             if !channel.inList {
                 self.didReadChannels.append(channel)
@@ -136,20 +136,30 @@ public final class HTTP2StreamMultiplexer: ChannelInboundHandler, ChannelOutboun
 
     public func channelActive(context: ChannelHandlerContext) {
         // We just got channelActive. Any previously existing channels may be marked active.
-        for channel in self.streams.values {
+        self.activateChannels(self.streams.values, context: context)
+        self.activateChannels(self.pendingStreams.values, context: context)
+
+        context.fireChannelActive()
+    }
+
+    private func activateChannels<Channels: Sequence>(_ channels: Channels, context: ChannelHandlerContext) where Channels.Element == MultiplexerAbstractChannel {
+        for channel in channels {
             // We double-check the channel activity here, because it's possible action taken during
             // the activation of one of the child channels will cause the parent to close!
             if context.channel.isActive {
                 channel.performActivation()
             }
         }
-        context.fireChannelActive()
     }
 
     public func channelInactive(context: ChannelHandlerContext) {
         for channel in self.streams.values {
             channel.receiveStreamClosed(nil)
         }
+        for channel in self.pendingStreams.values {
+            channel.receiveStreamClosed(nil)
+        }
+
         context.fireChannelInactive()
     }
 
@@ -188,6 +198,9 @@ public final class HTTP2StreamMultiplexer: ChannelInboundHandler, ChannelOutboun
         for channel in self.streams.values {
             channel.parentChannelWritabilityChanged(newValue: context.channel.isWritable)
         }
+        for channel in self.pendingStreams.values {
+            channel.parentChannelWritabilityChanged(newValue: context.channel.isWritable)
+        }
 
         context.fireChannelWritabilityChanged()
     }
@@ -409,7 +422,7 @@ extension HTTP2StreamMultiplexer {
     }
 
     internal func childChannelClosed(channelID: ObjectIdentifier) {
-        preconditionFailure("We don't currently support closing channels by 'channelID'")
+        self.pendingStreams.removeValue(forKey: channelID)
     }
 
     internal func childChannelWrite(_ frame: HTTP2Frame, promise: EventLoopPromise<Void>?) {

Tests/LinuxMain.swift

@@ -45,6 +45,7 @@ class LinuxMainRunnerImpl: LinuxMainRunner {
              testCase(HPACKRegressionTests.allTests),
              testCase(HTTP2FrameConvertibleTests.allTests),
              testCase(HTTP2FrameParserTests.allTests),
+             testCase(HTTP2FramePayloadStreamMultiplexerTests.allTests),
              testCase(HTTP2FramePayloadToHTTP1CodecTests.allTests),
              testCase(HTTP2StreamMultiplexerTests.allTests),
              testCase(HTTP2ToHTTP1CodecTests.allTests),

Tests/NIOHTTP2Tests/HTTP2FramePayloadStreamMultiplexerTests+XCTest.swift

@@ -0,0 +1,79 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the SwiftNIO open source project
+//
+// Copyright (c) 2017-2018 Apple Inc. and the SwiftNIO project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+//
+// HTTP2FramePayloadStreamMultiplexerTests+XCTest.swift
+//
+import XCTest
+
+///
+/// NOTE: This file was generated by generate_linux_tests.rb
+///
+/// Do NOT edit this file directly as it will be regenerated automatically when needed.
+///
+
+extension HTTP2FramePayloadStreamMultiplexerTests {
+
+   @available(*, deprecated, message: "not actually deprecated. Just deprecated to allow deprecated tests (which test deprecated functionality) without warnings")
+   static var allTests : [(String, (HTTP2FramePayloadStreamMultiplexerTests) -> () throws -> Void)] {
+      return [
+                ("testMultiplexerIgnoresFramesOnStream0", testMultiplexerIgnoresFramesOnStream0),
+                ("testHeadersFramesCreateNewChannels", testHeadersFramesCreateNewChannels),
+                ("testChannelsCloseThemselvesWhenToldTo", testChannelsCloseThemselvesWhenToldTo),
+                ("testChannelsCloseAfterResetStreamFrameFirstThenEvent", testChannelsCloseAfterResetStreamFrameFirstThenEvent),
+                ("testChannelsCloseAfterGoawayFrameFirstThenEvent", testChannelsCloseAfterGoawayFrameFirstThenEvent),
+                ("testFramesForUnknownStreamsAreReported", testFramesForUnknownStreamsAreReported),
+                ("testFramesForClosedStreamsAreReported", testFramesForClosedStreamsAreReported),
+                ("testClosingIdleChannels", testClosingIdleChannels),
+                ("testClosingActiveChannels", testClosingActiveChannels),
+                ("testClosePromiseIsSatisfiedWithTheEvent", testClosePromiseIsSatisfiedWithTheEvent),
+                ("testMultipleClosePromisesAreSatisfied", testMultipleClosePromisesAreSatisfied),
+                ("testClosePromiseFailsWithError", testClosePromiseFailsWithError),
+                ("testFramesAreNotDeliveredUntilStreamIsSetUp", testFramesAreNotDeliveredUntilStreamIsSetUp),
+                ("testFramesAreNotDeliveredIfSetUpFails", testFramesAreNotDeliveredIfSetUpFails),
+                ("testFlushingOneChannelDoesntFlushThemAll", testFlushingOneChannelDoesntFlushThemAll),
+                ("testUnflushedWritesFailOnClose", testUnflushedWritesFailOnClose),
+                ("testUnflushedWritesFailOnError", testUnflushedWritesFailOnError),
+                ("testWritesFailOnClosedStreamChannels", testWritesFailOnClosedStreamChannels),
+                ("testReadPullsInAllFrames", testReadPullsInAllFrames),
+                ("testReadIsPerChannel", testReadIsPerChannel),
+                ("testReadWillCauseAutomaticFrameDelivery", testReadWillCauseAutomaticFrameDelivery),
+                ("testReadWithNoPendingDataCausesReadOnParentChannel", testReadWithNoPendingDataCausesReadOnParentChannel),
+                ("testHandlersAreRemovedOnClosure", testHandlersAreRemovedOnClosure),
+                ("testHandlersAreRemovedOnClosureWithError", testHandlersAreRemovedOnClosureWithError),
+                ("testCreatingOutboundChannel", testCreatingOutboundChannel),
+                ("testCreatingOutboundChannelClient", testCreatingOutboundChannelClient),
+                ("testWritesOnCreatedChannelAreDelayed", testWritesOnCreatedChannelAreDelayed),
+                ("testWritesAreCancelledOnFailingInitializer", testWritesAreCancelledOnFailingInitializer),
+                ("testFailingInitializerDoesNotWrite", testFailingInitializerDoesNotWrite),
+                ("testCreatedChildChannelDoesNotActivateEarly", testCreatedChildChannelDoesNotActivateEarly),
+                ("testCreatedChildChannelActivatesIfParentIsActive", testCreatedChildChannelActivatesIfParentIsActive),
+                ("testInitiatedChildChannelActivates", testInitiatedChildChannelActivates),
+                ("testMultiplexerIgnoresPriorityFrames", testMultiplexerIgnoresPriorityFrames),
+                ("testMultiplexerForwardsActiveToParent", testMultiplexerForwardsActiveToParent),
+                ("testCreatedChildChannelCanBeClosedImmediately", testCreatedChildChannelCanBeClosedImmediately),
+                ("testCreatedChildChannelCanBeClosedBeforeWritingHeaders", testCreatedChildChannelCanBeClosedBeforeWritingHeaders),
+                ("testCreatedChildChannelCanBeClosedImmediatelyWhenBaseIsActive", testCreatedChildChannelCanBeClosedImmediatelyWhenBaseIsActive),
+                ("testCreatedChildChannelCanBeClosedBeforeWritingHeadersWhenBaseIsActive", testCreatedChildChannelCanBeClosedBeforeWritingHeadersWhenBaseIsActive),
+                ("testMultiplexerCoalescesFlushCallsDuringChannelRead", testMultiplexerCoalescesFlushCallsDuringChannelRead),
+                ("testMultiplexerDoesntFireReadCompleteForEachFrame", testMultiplexerDoesntFireReadCompleteForEachFrame),
+                ("testMultiplexerCorrectlyTellsAllStreamsAboutReadComplete", testMultiplexerCorrectlyTellsAllStreamsAboutReadComplete),
+                ("testMultiplexerModifiesStreamChannelWritabilityBasedOnFixedSizeTokens", testMultiplexerModifiesStreamChannelWritabilityBasedOnFixedSizeTokens),
+                ("testMultiplexerModifiesStreamChannelWritabilityBasedOnParentChannelWritability", testMultiplexerModifiesStreamChannelWritabilityBasedOnParentChannelWritability),
+                ("testMultiplexerModifiesStreamChannelWritabilityBasedOnFixedSizeTokensAndChannelWritability", testMultiplexerModifiesStreamChannelWritabilityBasedOnFixedSizeTokensAndChannelWritability),
+                ("testStreamChannelToleratesFailingInitializer", testStreamChannelToleratesFailingInitializer),
+                ("testInboundChannelWindowSizeIsCustomisable", testInboundChannelWindowSizeIsCustomisable),
+           ]
+   }
+}
+