Create http request with flurl and polly

Making http request is not easy to handle. for example dns changing, just create single HttpClient and …
also it’s need some default cofig and inject HttpClient to call api
Flurl is a library to make http request in simplest way
Polly is a library to automatic retry method if it riase expection

repository links:
polly github
flurl github

working with flurl is very easy and it’s not need any config or dependency injection
now you can use it like this:

var result = await "https://api.com"
    .SetQueryParams(new { api_key = "abc" })
    .WithOAuthBearerToken("my_token")
    .PostJsonAsync(new { first_name = firstName, last_name = lastName })
    .ReceiveJson<T>();

thre is no need to inject any HttpClient, you need just your url as string to call eat
we use these items:

• SetQueryParams : add custom parameter to url
• WithOAuthBearerToken : add auth token to header
• PostJsonAsync : data that send as post method
• ReceiveJson : result as json

also there are more method that you can see in this link
or use it like ReceiveJson() to make result type dynamic or add custom header to your request
and any thing else that HttpClient has and you need to work with rest api

this library has very good exception handling.
we can define some status code to prevent exception or make it default to raise exception in result status code is not 200:

url.AllowHttpStatus("400-404,6xx").GetAsync();
url.AllowAnyHttpStatus().GetAsync();

if we impact error, this exceptions raise:

• FlurlHttpTimeoutException
• FlurlHttpException

for example it modes that api return some info when exception happend.

return await ex.GetResponseJsonAsync() ??
             ex.GetBaseException().Message;

one of most important item that you should pat attention on it, is not create multi HttpClient in single call. this problem is handle currently by this library
this library is familier with test, also has fake implementation that you can see it in this link

[Test]
public void Test_Some_Http_Calling_Method() {
    using (var httpTest = new HttpTest()) {
        sut.CallThingThatUsesFlurlHttp();
    }
}

one of best library to retry code for example when time out happend, is Polly.
we can use it like this:

private readonly AsyncRetryPolicy _polly;

public MyConstructor()
{
    _polly = Policy
        .Handle<FlurlHttpTimeoutException>()
        .WaitAndRetryAsync(new[]
        {
            TimeSpan.FromSeconds(1),
            TimeSpan.FromSeconds(2)
        });
}

in Handle we can say that witch exceptin we want to retry, for example if FlurlHttpTimeoutException happen, we retry code
after that we define retry count in WaitAndRetryAsync
in this example we say that retry 2 times and in first time, wait 1 second and then wait 2 second
know we can use this code in every where we want:

var result = await _polly
    .ExecuteAsync(async ct =>
            await MyMethod(),
        cancellationToken);

for example if we want use it by flurl, we can do this:

var result = await _polly
    .ExecuteAsync(async ct =>
            await BaseInfo.WebApiAddress
                .AppendPathSegment("auth")
                .WithHeader(abc,
                    "in header")
                .PostJsonAsync(new
                {
                    Username = userUserName,
                    Password = userPassword
                }, ct).ReceiveJson<ResultInfo>(),
        cancellationToken);