private static void ExtractContent(string responseBody, FacebookClient facebookClient)
{
const string accessTokenKey = "access_token=";
const string expiresKey = "expires=";
Condition.Requires(responseBody).IsNotNullOrEmpty();
Condition.Requires(facebookClient).IsNotNull();
var data = responseBody.Split(new[] {'&'}, StringSplitOptions.RemoveEmptyEntries);
Condition.Requires(data).IsNotNull().HasLength(2);
int foundItems = 0;
foreach (var content in data)
{
// What do we have?
if (content.StartsWith(accessTokenKey))
{
facebookClient.AccessToken = ExtractContent(content, accessTokenKey);
foundItems++;
}
else if (content.StartsWith(expiresKey))
{
facebookClient.ExpiresOn =
DateTime.UtcNow.AddSeconds(Convert.ToInt32(ExtractContent(content, expiresKey)));
foundItems++;
}
}
// Check to make sure we've correctly extracted all the required data.
Condition.Requires(foundItems).IsEqualTo(2);
}
private FacebookClient TryGetFacebook(NameValueCollection parameters, string existingState)
{
Condition.Requires(parameters).IsNotNull().IsLongerThan(0);
Condition.Requires(existingState).IsNotNull();
// Is this a facebook callback?
var code = parameters["code"];
var state = parameters["state"];
if (!string.IsNullOrEmpty(code) &&
!string.IsNullOrEmpty(state))
{
// CSRF (state) check.
if (state != existingState)
{
throw new InvalidOperationException("The states do not match. It's possible that you may be a victim of a CSRF.");
}
// Now ask Facebook for a Token.
var facebookClient = new FacebookClient
{
Code = code,
State = state
};
FacebookProvider.RetrieveAccessToken(facebookClient);
return facebookClient;
}
// Maybe we have an error?
var errorReason = parameters["error_reason"];
var error = parameters["error"];
var errorDescription = parameters["error_description"];
if (!string.IsNullOrEmpty(errorReason) &&
!string.IsNullOrEmpty(error) &&
!string.IsNullOrEmpty(errorDescription))
{
return new FacebookClient
{
ErrorReason = errorReason,
Error = error,
ErrorDescription = errorDescription
};
}
// Nope. Didn't auth with Facebook.
return null;
}
public void GivenAMissingExpiresParam_RetrieveAccessToken_ThrowsAnException()
{
// Arrange.
var mockWebClientWrapper = MoqUtilities.MockedIWebClientWrapper(new[] { "access_token=foo&hi=ohnoes", null });
var facebookProvider = new FacebookProvider("a", "b", new Uri("http://www.google.com"),
mockWebClientWrapper.Object);
var facebookClient = new FacebookClient
{
Code = "aa",
State = "bb"
};
// Act.
var result = Assert.Throws<ArgumentException>(() => facebookProvider.RetrieveAccessToken(facebookClient));
// Assert.
Assert.NotNull(result);
Assert.Equal("value should be equal to 2. The actual value is 1.\r\nParameter name: value", result.Message);
}
public void GivenSomeInvalidResult_RetrieveAccessToken_ThrowsAnException()
{
// Arrange.
var mockWebClientWrapper = MoqUtilities.MockedIWebClientWrapper(new [] { "asds", null});
var facebookProvider = new FacebookProvider("a", "b", new Uri("http://www.google.com"),
mockWebClientWrapper.Object);
var facebookClient = new FacebookClient
{
Code = "aa",
State = "bb"
};
// Act.
var result = Assert.Throws<ArgumentException>(() => facebookProvider.RetrieveAccessToken(facebookClient));
// Assert.
Assert.NotNull(result);
Assert.Equal("value should contain 2 elements. value contains currently 1 element.\r\nParameter name: value", result.Message);
}
public void RetrieveAccessToken(FacebookClient facebookClient)
{
Condition.Requires(facebookClient).IsNotNull();
Condition.Requires(facebookClient.Code).IsNotNullOrEmpty();
var tokenUri = string.Format(TokenUri, ClientId, RedirectUri, ClientSecret, facebookClient.Code);
var responseBody = WebClient.DownloadString(tokenUri);
if (string.IsNullOrEmpty(responseBody))
{
throw new InvalidOperationException("No access token was received from Facebook.");
}
// Extract the relevant data.
ExtractContent(responseBody, facebookClient);
// Grab the user's information.
facebookClient.UserInformation = RetrieveUserInformation(facebookClient.AccessToken);
}
public void GivenValidCredentials_RetrieveAccessToken_ReturnsAnAccessTokenAndUserInformation()
{
// Arrange.
var mockWebClientWrapper = MoqUtilities.MockedIWebClientWrapper();
var facebookProvider = new FacebookProvider("a", "b", new Uri("http://www.google.com"),
mockWebClientWrapper.Object);
var facebookClient = new FacebookClient
{
Code = "aa",
State = "bb"
};
// Act.
facebookProvider.RetrieveAccessToken(facebookClient);
// Assert.
Assert.NotNull(facebookClient);
Assert.NotNull(facebookClient.AccessToken);
Assert.NotNull(facebookClient.Code);
Assert.NotNull(facebookClient.UserInformation);
Assert.True(facebookClient.UserInformation.Id > 0);
Assert.NotNull(facebookClient.UserInformation.FirstName);
Assert.NotNull(facebookClient.UserInformation.LastName);
}
public void GivenSomethingWeirdHappenedWhileTryingToRetrieveMeData_RetrieveAccessToken_ThrowsAnException()
{
// Arrange.
var mockWebClientWrapper = MoqUtilities.MockedIWebClientWrapper(new[] { "access_token=foo&expires=1", "ohcrap" });
var facebookProvider = new FacebookProvider("a", "b", new Uri("http://www.google.com"),
mockWebClientWrapper.Object);
var facebookClient = new FacebookClient
{
Code = "aa",
State = "bb"
};
// Act.
var result = Assert.Throws<InvalidOperationException>(() => facebookProvider.RetrieveAccessToken(facebookClient));
// Assert.
Assert.NotNull(result);
Assert.Equal("Failed to deserialize the json user information result from Facebook.", result.Message);
}
