From 1c39f444128c19ac4332f95ecd5c77794fcbebb5 Mon Sep 17 00:00:00 2001
From: Johannes Weiss <johannesweiss@apple.com>
Date: Thu, 21 Mar 2019 14:55:21 +0000
Subject: [PATCH] LineBasedFrameDecoder: Don't discard everything after EOF
 (#39)

Motivation:

LineBasedFrameDecoder discarded everything after EOF and delivered it in
the left-over bytes error. For the real world however that doesn't make
much sense, you'd want all previously received lines and only receive
the partial lines as left-overs.

Modifications:

deliver lines until there are only partial lines left, even in case of
EOF.

Result:

LineBasedFrameDecoder more useful
---
 Sources/NIOExtras/LineBasedFrameDecoder.swift      |  1 +
 .../NIOExtrasTests/LineBasedFrameDecoderTest.swift | 14 +++++++++++---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/Sources/NIOExtras/LineBasedFrameDecoder.swift b/Sources/NIOExtras/LineBasedFrameDecoder.swift
index 8150aab..8485924 100644
--- a/Sources/NIOExtras/LineBasedFrameDecoder.swift
+++ b/Sources/NIOExtras/LineBasedFrameDecoder.swift
@@ -49,6 +49,7 @@ public class LineBasedFrameDecoder: ByteToMessageDecoder {
     }
     
     public func decodeLast(context: ChannelHandlerContext, buffer: inout ByteBuffer, seenEOF: Bool) throws -> DecodingState {
+        while try self.decode(context: context, buffer: &buffer) == .continue {}
         if buffer.readableBytes > 0 {
             context.fireErrorCaught(NIOExtrasErrors.LeftOverBytesError(leftOverBytes: buffer))
         }
diff --git a/Tests/NIOExtrasTests/LineBasedFrameDecoderTest.swift b/Tests/NIOExtrasTests/LineBasedFrameDecoderTest.swift
index 53b6f42..e5e5598 100644
--- a/Tests/NIOExtrasTests/LineBasedFrameDecoderTest.swift
+++ b/Tests/NIOExtrasTests/LineBasedFrameDecoderTest.swift
@@ -25,7 +25,7 @@ class LineBasedFrameDecoderTest: XCTestCase {
         self.channel = EmbeddedChannel()
         self.decoder = LineBasedFrameDecoder()
         self.handler = ByteToMessageHandler(self.decoder)
-        try? self.channel.pipeline.addHandler(self.handler).wait()
+        XCTAssertNoThrow(try self.channel.pipeline.addHandler(self.handler).wait())
     }
 
     override func tearDown() {
@@ -141,6 +141,7 @@ class LineBasedFrameDecoderTest: XCTestCase {
 
             func channelRead(context: ChannelHandlerContext, data: NIOAny) {
                 let buffer = self.unwrapInboundIn(data)
+                context.fireChannelRead(data)
 
                 if buffer.readableBytes == 3 {
                     context.close(promise: nil)
@@ -159,9 +160,16 @@ class LineBasedFrameDecoderTest: XCTestCase {
         let handler = CloseWhenMyFavouriteMessageArrives(receivedLeftOversPromise: receivedLeftOversPromise)
         XCTAssertNoThrow(try self.channel.pipeline.addHandler(handler).wait())
         var buffer = self.channel.allocator.buffer(capacity: 16)
-        buffer.writeString("a\nbb\nccc\ndddd\neeeee\nffffff\n")
+        buffer.writeString("a\nbb\nccc\ndddd\neeeee\nffffff\nXXX")
         XCTAssertNoThrow(try self.channel.writeInbound(buffer))
-        XCTAssertNoThrow(try XCTAssertEqual("dddd\neeeee\nffffff\n",
+        for s in ["a", "bb", "ccc", "dddd", "eeeee", "ffffff"] {
+            XCTAssertNoThrow(XCTAssertEqual(s,
+                                            (try self.channel.readInbound(as: ByteBuffer.self)?.readableBytesView).map {
+                String(decoding: $0, as: Unicode.UTF8.self)
+            }))
+        }
+        XCTAssertNoThrow(XCTAssertNil(try self.channel.readInbound(as: ByteBuffer.self)))
+        XCTAssertNoThrow(try XCTAssertEqual("XXX",
                                             String(decoding: receivedLeftOversPromise.futureResult.wait().readableBytesView,
                                                    as: UTF8.self)))
     }