Add content auto decoding for download() (#986)

* Add content auto decoding for download

* Address review and run and make pass download.jl

Author: AtsushiSakai

src/download.jl

@@ -1,4 +1,5 @@
 using .Pairs
+using CodecZlib
 
 """
     safer_joinpath(basepart, parts...)
@@ -68,12 +69,6 @@ function determine_file(path, resp, hdrs)
                     )
 
 
-        # get the extension, if we are going to save it in encoded form.
-        # unlike a web-browser we don't automatically decompress
-        if header(resp, "Content-Encoding") == "gzip"
-            filename *= ".gz"
-        end
-        
         safer_joinpath(path, filename)
     else
         # We have been given a full filepath
@@ -121,6 +116,11 @@ function download(url::AbstractString, local_path=nothing, headers=Header[]; upd
         start_time = now()
         prev_time = now()
 
+        if header(resp, "Content-Encoding") == "gzip"
+            stream = GzipDecompressorStream(stream) # auto decoding
+            total_bytes = NaN # We don't know actual total bytes if the content is zipped.
+        end
+
         function report_callback()
             prev_time = now()
             taken_time = (prev_time - start_time).value / 1000 # in seconds

test/download.jl

@@ -73,7 +73,11 @@ import ..httpbin
         # Add gz extension if we are determining the filename
         gzip_content_encoding_fn = HTTP.download("https://$httpbin/gzip")
         @test isfile(gzip_content_encoding_fn)
-        @test last(splitext(gzip_content_encoding_fn)) == ".gz"
+
+        # Check content auto decoding
+        open(gzip_content_encoding_fn, "r") do f
+            @test HTTP.sniff(read(f, String)) == "application/json; charset=utf-8"
+        end
 
         # But not if the local name is fully given. HTTP#573
         mktempdir() do dir

test/runtests.jl

@@ -13,6 +13,7 @@ include(joinpath(dir, "resources/TestRequest.jl"))
             "chunking.jl",
             "utils.jl",
             "client.jl",
+            "download.jl",
             "multipart.jl",
             "parsemultipart.jl",
             "sniff.jl",