[WIP] Enhancement: Implement StrictClient

[localheinz]

Q	A
Bug fix?	no
New feature?	yes
BC breaks?	no
Deprecations?	no
Related tickets	fixes #41
Documentation	todo
License	MIT

What's in this PR?

This PR

• introduces a StrictClient which allows configuration of a sequence of matchers, and which will throw an exception when a request was sent that was not expected

Example Usage

Without configured sequence

<?php

use Http\Mock\StrictClient;
use Nyholm\Psr7\Request;

$httpClient = new StrictClient();

var_dump($httpClient->hasCompletedSequence()); // true

// UnexpectedRequestException will be thrown
$httpClient->sendRequest(new Request(
    'GET',
    '/foo/bar'
));

With configured sequence and an unexpected additional request

<?php

use Http\Message\RequestMatcher\CallbackRequestMatcher;
use Http\Mock\StrictClient;
use Nyholm\Psr7\Request;
use Nyholm\Psr7\Response;
use Psr\Http\Message\RequestInterface;

$httpClient = new StrictClient();

var_dump($httpClient->hasCompletedSequence()); // true

$httpClient->on(
    new CallbackRequestMatcher(static function (RequestInterface $request): bool {
        return 'POST' === $request->getMethod() && '/foo/bar' === (string) $request->getUri();
    }),
    new Response(
        200,
        [],
        'Sounds good!'
    )
);

var_dump($httpClient->hasCompletedSequence()); // false

$httpClient->sendRequest(new Request(
    'POST',
    '/foo/bar'
));

var_dump($httpClient->hasCompletedSequence()); // true

// UnexpectedRequestException will be thrown
$httpClient->sendRequest(new Request(
    'POST',
    '/foo/bar'
));

With configured sequence and an unexpected request

<?php

use Http\Message\RequestMatcher\CallbackRequestMatcher;
use Http\Mock\StrictClient;
use Nyholm\Psr7\Request;
use Nyholm\Psr7\Response;
use Psr\Http\Message\RequestInterface;

$httpClient = new StrictClient();

var_dump($httpClient->hasCompletedSequence()); // true

$httpClient->on(
    new CallbackRequestMatcher(static function (RequestInterface $request): bool {
        return 'POST' === $request->getMethod() && '/foo/bar' === (string) $request->getUri();
    }),
    new Response(
        200,
        [],
        'Sounds good!'
    )
);

var_dump($httpClient->hasCompletedSequence()); // false

$httpClient->sendRequest(new Request(
    'POST',
    '/foo/bar'
));

var_dump($httpClient->hasCompletedSequence()); // true

// UnexpectedRequestException will be thrown
$httpClient->sendRequest(new Request(
    'GET',
    '/foo/bar'
));

With configured sequence, but not all requests have been sent yet

<?php

use Http\Message\RequestMatcher\CallbackRequestMatcher;
use Http\Mock\StrictClient;
use Nyholm\Psr7\Request;
use Nyholm\Psr7\Response;
use Psr\Http\Message\RequestInterface;

$httpClient = new StrictClient();

var_dump($httpClient->hasCompletedSequence()); // true

$httpClient->on(
    new CallbackRequestMatcher(static function (RequestInterface $request): bool {
        return 'POST' === $request->getMethod() && '/foo/bar' === (string) $request->getUri();
    }),
    new Response(
        200,
        [],
        'Sounds good!'
    )
);

$httpClient->on(
    new CallbackRequestMatcher(static function (RequestInterface $request): bool {
        return 'GET' === $request->getMethod() && '/foo/bar' === (string) $request->getUri();
    }),
    new Response(
        400,
        [],
        'Now is not a good time'
    )
);

var_dump($httpClient->hasCompletedSequence()); // false

$httpClient->sendRequest(new Request(
    'POST',
    '/foo/bar'
));

var_dump($httpClient->hasCompletedSequence()); // false

With configured sequence and all requests have been sent in correct order

<?php

use Http\Message\RequestMatcher\CallbackRequestMatcher;
use Http\Mock\StrictClient;
use Nyholm\Psr7\Request;
use Nyholm\Psr7\Response;
use Psr\Http\Message\RequestInterface;

$httpClient = new StrictClient();

var_dump($httpClient->hasCompletedSequence()); // true

$httpClient->on(
    new CallbackRequestMatcher(static function (RequestInterface $request): bool {
        return 'POST' === $request->getMethod() && '/foo/bar' === (string) $request->getUri();
    }),
    new Response(
        200,
        [],
        'Sounds good!'
    )
);

$httpClient->on(
    new CallbackRequestMatcher(static function (RequestInterface $request): bool {
        return 'GET' === $request->getMethod() && '/foo/bar' === (string) $request->getUri();
    }),
    new Response(
        400,
        [],
        'Now is not a good time'
    )
);

var_dump($httpClient->hasCompletedSequence()); // false

$httpClient->sendRequest(new Request(
    'POST',
    '/foo/bar'
));

var_dump($httpClient->hasCompletedSequence()); // false

$httpClient->sendRequest(new Request(
    'GET',
    '/foo/bar'
));

var_dump($httpClient->hasCompletedSequence()); // true

Checklist

• Updated CHANGELOG.md to describe BC breaks / deprecations | new feature | bugfix
• Documentation pull request created (if not simply a bugfix)

[localheinz]

@dbu

I probably should have openend a draft pull request.

We're currently testing this in a project, perhaps we'll wait a bit to see how well this goes, and then I'll circle back to see if this needs improvements.