NAME
    Test::HTTP::MockServer - Implement a mock HTTP server for use in tests

SYNOPSIS
      use Test::HTTP::MockServer;
  
      my $server = Test::HTTP::MockServer->new();
      my $url = $server->url_base();
      # inject $url as the config for the remote http service.
  
      my $handle_request_phase1 = sub {
          my ($request, $response) = @_;
          ...
      };
      $server->start_mock_server($handle_request_phase1);
      # run your tests against $handle_request_phase1
      $server->stop_mock_server();
  
      my $handle_request_phase2 = sub {
          my ($request, $response) = @_;
          ...
      };
      $server->start_mock_server($handle_request_phase2);
      # run your tests against $handle_request_phase2
      $server->stop_mock_server();

DESCRIPTION
    Sometimes, when writing a test, you don't have to oportunity to do
    dependency injection of the type of transport used in a specific API.
    Sometimes that code willl unequivocally always use actual HTTP and the
    only control you have is over the host and port to which it will
    connect.

    This class offer a simple way to mock the service being called. It does
    that by binding to a random port on localhost and allowing you to
    inspect which port that was. Using a random port means that this can be
    used by tests running in parallel on the same host.

    The socket will be bound and listened on the main test process, such
    that the lifetime of the connection is defined by the lifetime of the
    test itself.

    Since the socket will be already bound and listened to, the two conntrol
    methods (start_mock_server and stop_mock_server) fork only for the
    accept call, which means that it is safe to call start and stop several
    times during the test in order to change the expectations of the mocked
    code.

    That allows you to easily configure the expectations of the mock server
    across each step of your test case. On the other hand, it also means
    that no state is shared between the code running in the mock server and
    the test code.

METHOS
    new()
        Creates a new MockServer object.

    bind_mock_server()
        Finds a random available port, bind and listen to it. This allows to
        inspect what the mock url of the portal will be before the server
        forks to start. If the random port is already in use, it will keep
        trying until it finds one that works.

    host()
        Returns the host which the mock server is binding to. It will call
        bind_mock_server if that was not yet initialized. The current
        version always bind to 127.0.0.1.

    port()
        Returns the port which the mock server is bound and is listening to.
        It will call bind_mock_server if that was not yet initialized.

    base_url()
        Returns the url to be used as the base url for requests into the
        mock server. It will bind_mock_server if that was not yet
        initialized.

    start_mock_server($request_processor)
        This will bind_mock_server if that was not yet initialized, then
        fork to accept connections.

        In order to make it easier to have state propagate across different
        requests in the mock implementation, there will only be one
        connection at a time, and every request in that connection will be
        handled serially.

    stop_mock_server()
        This will kill the server running on the background, but it won't
        unbind the socket, which means that you can just call
        start_mock_server again with a different request_processor and the
        same url will be preserved.

THE REQUEST PROCESSOR
    The request processor is the code reference sent as an argument to the
    start_mock_server call which will receive all the requests received via
    the socket.

    Whenever a request is received, the code reference will be called with
    two arguments:

    $request
        An HTTP::Request object with the request as it was received.

    $response
        An HTTP::Response object that will be sent back. It is initialized
        with "200 OK" and no content

    If your code dies while processing a request, a "500 Internal Server
    Error" response will be generated.

COPYRIGHT
    Copyright 2016 Bloomberg Finance L.P.

    Licensed under the Apache License, Version 2.0 (the "License"); you may
    not use this file except in compliance with the License. You may obtain
    a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.

