Deprecate the wget backend

It doesn't appear that anyone is using it, since I haven't received a
single bug report. And it's a maintenance burden, e.g. I cannot install
posix-spawn on my M1 on Ruby 3.3.1 anymore, and the tests without
posix-spawn are failing for some reason. So, we remove it from the
docs and recommend one of the three other backends.

This will allow us to potentially use WebMock in the future instead of
spinning up a real HTTP server.

README.md

@@ -1,8 +1,8 @@
 # Down
 
 Down is a utility tool for streaming, flexible and safe downloading of remote
-files. It can use [open-uri] + `Net::HTTP`, [http.rb], [HTTPX], or `wget` as
-the backend HTTP library.
+files. It can use [open-uri] + `Net::HTTP`, [http.rb] or [HTTPX] as the backend
+HTTP library.
 
 ## Installation
 
@@ -235,7 +235,6 @@ The following backends are available:
 * [Down::NetHttp](#downnethttp) (default)
 * [Down::Http](#downhttp)
 * [Down::Httpx](#downhttpx)
-* [Down::Wget](#downwget)
 
 You can use the backend directly:
 
@@ -465,52 +464,6 @@ io #=> #<Down::ChunkedIO ...>
 It's implemented in much of the same way as `Down::Http`, so be sure to check
 its docs for ways to pass additional options.
 
-### Down::Wget (experimental)
-
-The `Down::Wget` backend implements downloads using the `wget` command line
-utility.
-
-```rb
-gem "down", "~> 5.0"
-gem "posix-spawn" # omit if on JRuby
-gem "http_parser.rb"
-```
-```rb
-require "down/wget"
-
-tempfile = Down::Wget.download("http://nature.com/forest.jpg")
-tempfile #=> #<Tempfile:/var/folders/k7/6zx6dx6x7ys3rv3srh0nyfj00000gn/T/20150925-55456-z7vxqz.jpg>
-
-io = Down::Wget.open("http://nature.com/forest.jpg")
-io #=> #<Down::ChunkedIO ...>
-```
-
-One major advantage of `wget` is that it automatically resumes downloads that
-were interrupted due to network failures, which is very useful when you're
-downloading large files.
-
-However, the Wget backend should still be considered experimental, as it wasn't
-easy to implement a CLI wrapper that streams output, so it's possible that I've
-made mistakes. Let me know how it's working out for you 😉.
-
-#### Additional arguments
-
-You can pass additional arguments to the underlying `wget` commmand via symbols:
-
-```rb
-Down::Wget.download("http://nature.com/forest.jpg", :no_proxy, connect_timeout: 3)
-Down::Wget.open("http://nature.com/forest.jpg", user: "janko", password: "secret")
-```
-
-You can also initialize the backend with default arguments:
-
-```rb
-wget = Down::Wget.new(:no_proxy, connect_timeout: 3)
-
-wget.download("http://nature.com/forest.jpg")
-wget.open("http://nature.com/forest.jpg")
-```
-
 ## Development
 
 Tests require that a [httpbin] server is running locally, which you can do via Docker:

down.gemspec

@@ -6,7 +6,7 @@ Gem::Specification.new do |spec|
 
   spec.required_ruby_version = ">= 2.3"
 
-  spec.summary      = "Robust streaming downloads using Net::HTTP, HTTP.rb or wget."
+  spec.summary      = "Robust streaming downloads using Net::HTTP, http.rb or HTTPX."
   spec.homepage     = "https://github.com/janko/down"
   spec.authors      = ["Janko Marohnić"]
   spec.email        = ["[email protected]"]
@@ -21,13 +21,6 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "mocha", "~> 1.5"
   spec.add_development_dependency "rake"
   spec.add_development_dependency "httpx", "~> 0", "< 2.0.0"
-  # http 5.0 drop support of ruby 2.3 and 2.4. We still support those versions.
-  if RUBY_VERSION >= "2.5"
-    spec.add_development_dependency "http", "~> 5.0"
-  else
-    spec.add_development_dependency "http", "~> 4.3"
-  end
-  spec.add_development_dependency "posix-spawn" unless RUBY_ENGINE == "jruby"
-  spec.add_development_dependency "http_parser.rb" unless RUBY_ENGINE == "jruby"
+  spec.add_development_dependency "http", RUBY_VERSION >= "2.5" ? "~> 5.0" : "~> 4.3"
   spec.add_development_dependency "warning" if RUBY_VERSION >= "2.4"
 end

lib/down/wget.rb

@@ -1,5 +1,7 @@
 # frozen-string-literal: true
 
+warn "The Down::Wget backend has been deprecated and will be removed in the next major version. Please use the Net::HTTP/open-uri, http.rb or HTTPX backend instead."
+
 begin
   require "posix-spawn"
 rescue LoadError