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I'm Jason, a web applications developer in the San Francisco Bay area.

Detecting if WebMock is enabled for Net::HTTP

I ran into an issue where we were mocking HTTP responses 400+ in our Rspec tests, which resulted in our application logging an error and a stack trace. When we expect errors because we’re using WebMock to emulate an HTTP 500 response, logging the stack trace involved can be too verbose.

Sometimes we might need the stack trace, such as when a developer is debugging code involving the handling of error responses. I discussed this with other developers they expressed that they don’t want to introduce a global configuration flag to turn the stack trace logging on or off.

The ideal solution was to simply not log the stack trace when WebMock is being used in the ‘test’ environment.

We’re using HTTParty, which uses Net::HTTP. I did some investigating and discovered that when WebMock is enabled (via WebMock.enable!), that it replaces the HTTP module with it’s own. There isn’t anything clear to indicate if WebMock is enabled or not, however I noticed that Net::HTTP.socket_type is redefined as StubSocket when WebMock is enabled.

> Net::HTTP.socket_type
=> Net::BufferedIO
> WebMock.enable!
=> {:net_http=>WebMock::HttpLibAdapters::NetHttpAdapter}
> Net::HTTP.socket_type
=> StubSocket
> WebMock.disable!
> Net::HTTP.socket_type
=> Net::BufferedIO

I don’t see the equivalent modification in other adapters, such as Curb

I’m going to open a Github issue requesting support such as this. Perhaps a simple unified call to set a class variable in WebMock class itself, with a corresponding WebMock.is_enabled? method. I’ve made an issue to request this. I will make a pull request soon.