danielwertheim

danielwertheim


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Developer that lives by the mantra "code is meant to be shared".

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New lib - Requester for Web API response validation

Daniel WertheimDaniel Wertheim

Recently I had the need to write some tests against a web API returning JSON. I found FrisbyJS which worked really well, and thought: “Why not put together this in C# and .Net?”. So this is what Requester is. It’s a small lib, that assists you with making HTTP-requests against web APIs and then helps you validates the responses. E.g. validation of JSON-schema etc. Read along and I’ll give you some short intro on how to use it. Please be advised though. It’s an early release.

Disclaimer, Remarks…

This is still an early release hence stuff WILL change. Especially additions for URL-building and helpers for doing requests that should not be validated.

NuGet

Of course. Just do:

install-package requester  

Then import the namespaces:

using Requester;  
using Requester.Validation;  

Samples

The samples below are written to work against a local CouchDB installation.

When.Put("http://localhost:5984/mydb")  
    .TheResponse(should => should.BeSuccessful());

When.Head("http://localhost:5984/mydb")  
    .TheResponse(should => should.BeSuccessful());

Authentication

For now, only basic authentication is supported and it can be defined in two ways: via URL or using WithAuthentication.

When.Put("http://foo:bar@localhost:5984/mydb")  
    .TheResponse(should => should.BeSuccessful());

//vs

When.Put("http://localhost:5984/mydb", cfg => cfg  
    .WithBasicAuthorization("foo", "bar"))
    .TheResponse(should => should.BeSuccessful());

Please note, that when passing credentials in the URL, you need to encode your values.

Custom headers

When.Put(DbUrl, cfg => cfg  
    .WithHeader("foo", "bar"))
    .WithHeader(h => h.Accept, "application/json"))
    .TheResponse(should => should.BeSuccessful());

Expectations

The idea is that you can use whatever testing framework you want. Below, I'm using xUnit. But it could just as well be NUnit.

public class Candy  
{
    private const string DbUrl = "http://sa:test@localhost:5984/mydb/";

    [Fact]
    public void Can_eat_candy_like_a_monster()
    {
        When.Put(DbUrl)
            .TheResponse(should => should.BeSuccessful());

        When.Put(DbUrl, cfg => cfg
            .WithHeader(h => h.Accept, "application/json"))
            .TheResponse(should => should.BeSuccessful());

        When.Head(DbUrl)
            .TheResponse(should => should.BeSuccessful());

        When.PostOfJson(DbUrl, 
                        "{"_id":"doc1",
                          "name": "Daniel Wertheim",
                          "address":{"street":"One way", "zip":12345},
                          "hobbies":["programming","running"]}")
            .TheResponse(should => should
                .BeSuccessful()
                .HaveStatus(HttpStatusCode.Created));

        When.PutOfJson(DbUrl + "doc2",
                       "{"name": "Daniel Wertheim",
                         "address":{"street":"Two way", "zip":54321},
                         "hobbies":["programming","running"]}")
            .TheResponse(should => should
                .BeSuccessful()
                .HaveStatus(HttpStatusCode.Created));

        When.GetOfJson(DbUrl + "doc1")
            .TheResponse(should => should
                .BeSuccessful()
                .BeJsonResponse()
                .HaveJsonConformingToSchema(@"{
                    _id: {type: 'string', required: true},
                    _rev: {type: 'string', required: true},
                    name: {type: 'string'},
                    address: {type: 'object',
                              properties: {zip: {type: 'integer'}}},
                    hobbies: {type: 'array', items: {type: 'string'}}
                }")
                .Match(new {_id = "doc1", name = "Daniel Wertheim"}));

        When.GetOfJson(DbUrl + "doc2")
            .TheResponse(should => should
                .BeSuccessful()
                .BeJsonResponse()
                .HaveSpecificValue("_id", "doc2")
                .HaveSpecificValue("hobbies[0]", "programming")
                .HaveSpecificValue("address.zip", 54321));

        var doc1 = When.Head(DbUrl + "doc1")
                       .TheResponse(should => should.BeSuccessful());

        When.Delete(DbUrl + "doc1?rev=" + doc1.ETag)
            .TheResponse(should => should.BeSuccessful());
    }
}

Violations will show in your test runner. The sample below violates HaveJsonConformingToSchema.

My_test_one failed

Requester.Validation.RequesterAssertionException : Expected object to be conforming to specified JSON schema.  
Failed when inspecting 'address.street' due to 'Invalid type.  
Expected Integer but got String. Line 1, position 112.'

RequestUri: http://localhost:5984/mydb/doc1  
RequestMethod: GET  
Status: OK(200)  
Reason: OK  
ETag: 1-23c4402e369a7a56059d912e53d320ee  
ContentType:application/json  
HasContent:True  
Content:<NOT BEING SHOWED>  

HttpRequester

The HttpRequester is what is used but the When constructs, and can of course be used to perform Http-requests.

using(var requester = new HttpRequester("http://localhost:5984/mydb"))  
{
  //Ensure db is created
  await requester.SendAsync(new HttpRequest(HttpMethod.Put));

  //Create a document
  await requester.SendAsync(
    new HttpRequest(HttpMethod.Put, "/mydocid").WithJsonContent(someJson));
}

HttpResponse

The response of the HttpRequester is a HttpResponse.

//Everything is a response (HEAD, GET, POST, PUT, DELETE)
var get = await requester.SendAsync(  
    new HttpRequest(HttpMethod.Get, "/mydocid"));

//The resonse has like: StatusCode, Reason, Content, ETag, ContentType etc.
Debug.WriteLine(get.ToStringDebugVersion(includeContent: true));  

The out put would be:

RequestUri: http://localhost:5984/mydb/doc1  
RequestMethod: GET  
Status: OK(200)  
Reason: OK  
ETag: 1-23c4402e369a7a56059d912e53d320ee  
ContentType:application/json  
HasContent:True  
Content:{  
    "_id":"doc1",
    "_rev":"1-23c4402e369a7a56059d912e53d320ee",
    "name":"Daniel Wertheim",
    "address":{"street":"One way","zip":12345},
    "hobbies":["programming","running"]}

Custom testing framework assertion exceptions

To keep down some dependencies, Requester throws a custom RequesterAssertionException but if you want your specific testing framework exceptions, just hook them in:

AssertionExceptionFactory.ExceptionFn = msg =>  
    new NUnit.Framework.AssertionException(msg);

The end

Well not the end of the lib. There are lots of stuff to add. But at least it’s out.

//Daniel

Developer that lives by the mantra "code is meant to be shared".

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