If you want a remote server to do selenium testing, this is a better way
Canonical screen-shot: Producing screen-shots that can be compared between different
computers can be quite difficult. Often subtle differences in systems, such as what fonts are
installed can result in widely varying screen-shots. Therefore the right thing to do when using
webdrivercss is to have a known-good system to produce all screen-shots. One approach to this
is to set up
webdriverio-server on a dedicated server somewhere and have
all requests for selenium tests to that machine. Another approach is to use a system that can
consistently produce the same machine each time (e.g. using Docker). This way developers can each
have their own independent systems for running tests which are identical to each other and to the
Test server: There will be a dedicated server process that can either run locally or on another machine for the purposes of getting testing requests, processing them, and sending back results.
There are two use-cases for implementing webdriverio-server:
Running tests on a laptop (Mac OS/X) in order to watch the progress and to visually inspect how a test is executing. Note that this will not produce canonical screenshots that can be used across a team.
Running tests for the purpose of creating canonical screen-shots that can be checked in as part of a pull-request.
Installing on OS/X
Install the following dependencies:
Next install webdriverio-server and run the init script:
npm install -g webdriverio-serverwebdriverio-server-init local
Now you're ready to run the web service which will respond to test-upload requests:
DEBUG=server PORT=3000 webdriverio-server
In this case, you'll be sending test requests to localhost on port 3000.
Installing on Docker
If you want to share screenshots between developers, you'll need to set up a testing system that produces 100% consistent images. This can be done by doing the above steps on a dedicated server or by setting up a Docker system on developer systems and the CI system. The canonical setup requires that you have Docker installed with appropriate permissions for running user.
npm install -g webdriverio-serverwebdriverio-server-init docker
To start the testing server, use the run command:
$ docker run -Pd webdriverio-server34a841cb50a0555e40060367c862d50f823c0edcd0a2fe6537b5666f7588e73d
To stop the test container, run
docker stop with the image id that docker provided, e.g.
$ docker stop 34a841cb50a0555e40060367c862d50f823c0edcd0a2fe6537b5666f7588e73d34a841cb50a0555e40060367c862d50f823c0edcd0a2fe6537b5666f7588e73d
In this case, you'll be sending test requests to the docker server. Note that docker maps ports on the container to random ports on the host machine. To find out what ports
Using the server
Now that you have a running webdriverio-server, you need to be able to submit tests to it. This is not a trivial procedure. You will need to set up your testing directory properly and to submit a tarball to the server with your entire site in it, packaged up properly with the existing screenshots, if applicable.
To make this easier, utilize the webdriverio-client to make test requests.