WIP: Add ReadTimeoutError Exception (#693)

* add Readtimeoutexception

* add tests

* Update client.jl

src/TimeoutRequest.jl

@@ -4,6 +4,14 @@ import ..Layer, ..request
 using ..ConnectionPool
 import ..@debug, ..DEBUG_LEVEL
 
+struct ReadTimeoutError <:Exception
+    readtimeout::Int
+end
+
+function Base.showerror(io::IO, e::ReadTimeoutError)
+    print(io, "ReadTimeoutError: Connection closed after $(e.readtimeout) seconds")
+end
+
 """
     request(TimeoutLayer, ::IO, ::Request, body) -> HTTP.Response
 
@@ -16,9 +24,11 @@ function request(::Type{TimeoutLayer{Next}}, io::IO, req, body;
                  readtimeout::Int=0, kw...) where Next
 
     wait_for_timeout = Ref{Bool}(true)
+    timedout = Ref{Bool}(false)
 
     @async while wait_for_timeout[]
         if isreadable(io) && inactiveseconds(io) > readtimeout
+            timedout[] = true
             close(io)
             @debug 1 "💥  Read inactive > $(readtimeout)s: $io"
             break
@@ -28,6 +38,11 @@ function request(::Type{TimeoutLayer{Next}}, io::IO, req, body;
 
     try
         return request(Next, io, req, body; kw...)
+    catch e
+        if timedout[]
+           throw(ReadTimeoutError(readtimeout))
+        end
+        rethrow(e)
     finally
         wait_for_timeout[] = false
     end

test/client.jl

@@ -213,7 +213,10 @@ end
 end
 
 @testset "readtimeout" begin
-    @test_throws HTTP.IOError HTTP.get("http://httpbin.org/delay/5"; readtimeout=1, retry=false)
+    @test_throws HTTP.TimeoutRequest.ReadTimeoutError begin
+        HTTP.get("http://httpbin.org/delay/5"; readtimeout=1, retry=false)
+    end
+    HTTP.get("http://httpbin.org/delay/1"; readtimeout=2, retry=false)
 end
 
 @testset "Retry all resolved IP addresses" begin