From fbc5415096678e7364b78a20e99ba777542ab0fe Mon Sep 17 00:00:00 2001
From: Takafumi Arakaki <aka.tkf@gmail.com>
Date: Thu, 26 Dec 2019 14:05:27 -0800
Subject: [PATCH 1/2] Return the first argument from `put!`

---
 base/channels.jl | 7 ++++++-
 test/channels.jl | 6 ++++++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/base/channels.jl b/base/channels.jl
index f3b53188a791f..a9e060663e801 100644
--- a/base/channels.jl
+++ b/base/channels.jl
@@ -304,14 +304,19 @@ Append an item `v` to the channel `c`. Blocks if the channel is full.
 
 For unbuffered channels, blocks until a [`take!`](@ref) is performed by a different
 task.
+Return the first argument.
 
 !!! compat "Julia 1.1"
     `v` now gets converted to the channel's type with [`convert`](@ref) as `put!` is called.
+
+!!! compat "Julia 1.4"
+    `put!` now returns the channel `c`; older versions of Julia returned `v`.
 """
 function put!(c::Channel{T}, v) where T
     check_channel_state(c)
     v = convert(T, v)
-    return isbuffered(c) ? put_buffered(c, v) : put_unbuffered(c, v)
+    isbuffered(c) ? put_buffered(c, v) : put_unbuffered(c, v)
+    return c
 end
 
 function put_buffered(c::Channel, v)
diff --git a/test/channels.jl b/test/channels.jl
index fc5852df62dbc..a1f8d23cedbfa 100644
--- a/test/channels.jl
+++ b/test/channels.jl
@@ -456,3 +456,9 @@ let t = @async nothing
     wait(t)
     @test_throws ErrorException("schedule: Task not runnable") schedule(t, nothing)
 end
+
+@testset "put!(c, v) -> c" begin
+    c = Channel(Inf)
+    @test put!(c, nothing) === c
+    @test push!(c, nothing) === c
+end

From 7b3dcd5b3f15a4d8ae662ab8c35e613d4c867e20 Mon Sep 17 00:00:00 2001
From: Takafumi Arakaki <aka.tkf@gmail.com>
Date: Thu, 26 Dec 2019 15:38:02 -0800
Subject: [PATCH 2/2] Fix tests

---
 test/channels.jl | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/test/channels.jl b/test/channels.jl
index a1f8d23cedbfa..e172725a7a445 100644
--- a/test/channels.jl
+++ b/test/channels.jl
@@ -19,7 +19,7 @@ end
 
     c = Channel(1)
     @test eltype(c) == Any
-    @test put!(c, 1) == 1
+    @test put!(c, 1) === c
     @test isready(c) == true
     @test take!(c) == 1
     @test isready(c) == false
@@ -35,7 +35,8 @@ end
 
     c = Channel{Int}(Inf)
     @test eltype(c) == Int
-    pvals = map(i->put!(c,i), 1:10^6)
+    pvals = 1:10^6
+    foldl(put!, pvals; init=c)
     tvals = Int[take!(c) for i in 1:10^6]
     @test pvals == tvals
 
@@ -162,7 +163,7 @@ using Distributed
 
     if N > 0
         for i in 1:5
-            @test put!(cs[i], 2) === 2
+            @test put!(cs[i], 2) === cs[i]
         end
     end
     for i in 1:5
@@ -457,8 +458,7 @@ let t = @async nothing
     @test_throws ErrorException("schedule: Task not runnable") schedule(t, nothing)
 end
 
-@testset "put!(c, v) -> c" begin
+@testset "push!(c, v) -> c" begin
     c = Channel(Inf)
-    @test put!(c, nothing) === c
     @test push!(c, nothing) === c
 end