Automating Azure Resource Manager

I’ve recently been (finally) getting to speed with Azure Resource Manager (ARM). It’s the management layer that drives the new Azure Portal and also features like Resource Groups and Role-Based Access Control.

You can interact with ARM in a number of ways:

To authenticate to the ARM API you need to use an Azure AD credential. This is all well and good if you are logged into the Portal, or running a script on your computer (where a web browser login prompt to Azure AD will pop up), but when automating your API calls that’s not available.

Luckily there is a post by David Ebbo that describes how to generate a Service Principal (equivalent of the concept of an Active Directory Service Account) attached to an Azure AD application.

The only problem with this post is that there are a few manual steps and it’s quite fiddly to do (by David’s own admission). I’ve developed a PowerShell module that you can use to idempotently create a Service Principal against either an entire Azure subscription or against a specific Resource Group that you can then use to automate your ARM code.

I’ve published the code to GitHub.

In order to use it you need to:

  1. Ensure you have the Windows Azure PowerShell commandlets installed
  2. Download the Set-ARMServicePrincipalCredential.psm1 file from my GitHub repository
  3. Download the Azure Key Vault PowerShell commandlets and put the AADGraph.ps1 file next to the file from GitHub
  4. Execute the Set-ARMServicePrincipalCredential command as per the examples on GitHub

This will pop up a web browser prompt to authenticate (this will happen twice since I’m using two disjointed libraries – hopefully this will get resolved if Azure AD commandlets end up becoming integrated with the Azure Commandlets) give you the following information:

  • Tenant ID
  • Client ID
  • Password

From there you have all the information you need to authenticate your automated script with ARM.

If using PowerShell then this will look like:

    $securePassword = ConvertTo-SecureString $Password -AsPlainText -Force
    $servicePrincipalCredentials = New-Object System.Management.Automation.PSCredential ($ClientId, $securePassword)
    Add-AzureAccount -ServicePrincipal -Tenant $TenantId -Credential $servicePrincipalCredentials | Out-Null

If using ARMClient then this will look like:

    armclient spn $TenantId $ClientId $Password | Out-Null

One last note: make sure you store the password securely when automating the script, e.g. TeamCity password, Bamboo password or Octopus sensitive variable.

Testing AngularJS directives using Approval Tests

I recently had an application I was developing using AngularJS that contained a fair number of directives that were somewhat complex in that the logic that backed them was contained in services that called HTTP APIs. The intent was to provide a single JavaScript file that designers at the company I was working at could include and then build product pages using just HTML (via the directives). I needed to provide some confidence when making changes to the directives and pin down the behaviour.

As explained below, I ended up doing this via approval tests and I’ve published how I did it on GitHub.

Why I wanted to use Approval Tests

In order to test these directives I didn’t want to have to perform tedious DOM inspection code to determine if the directives did what I wanted. Most AngularJS directive testing examples you will find on the Internet tell you to do this though, including the official documentation.

Side note: in my research I stumbled across the ng-directive-testing library, which I feel is an improvement over most example code out there and if you do want to inspect the DOM as part of your testing I recommend you check it out.

This style of testing works fine for small, simple directives, but I felt would be tedious to write and fragile for my use case. Instead, I had an idea that I wanted to apply the approval tests technique.

I use this technique when I have a blob of JSON, XML, HTML, text etc. that I want to verify is what I expect and pin it down without having to write tedious assertions against every aspect of it – hence this technique fitted in perfectly with what I wanted to achieve with testing the directives.

How I did it

Given that directives need the DOM it was necessary to run the tests in a web browser. In this case I decided to do it via Karma since I was already using Node JS to uglify the JavaScript.

ApprovalTests requires access to the filesystem in order to write the approval files and then access to open processes on the computer to pop open a diff viewer if there is a difference in the output. This is not possible from the web browser. Thus, even though there is a JavaScript port of ApprovalTests (for NodeJS) I wasn’t able to use it directly in my tests.

While contemplating my options, it occured to me I could spin up a NodeJS server to run the approvals code and simply call it from the browser – it’s not much different to how Karma gets test results. After that realisation I stumbled across approvals-server – someone had already implemented it! Brilliant!

From there it was simply a matter of stitching up the code to all work together – in my case using Grunt as the Task Runner.

Example code

To that end, I have published a repository with a contrived example that demonstrates how to test a directive using Approval Tests.

The main bits to look at are:

  • gruntfile.js – contains the grunt configuration I used including my Grunt tasks for the approval server, which probably should be split into a separate file or published to npm (feel free to send me a PR)
  • app/spec/displayproducts.directive.spec.js – contains the example test in all it’s glory
  • app/test-helpers/approvals/myapp-display-products-should-output-product-information.approved.txt – the approval file for the example test
  • app/test-helpers/approvals.js – the code to get name of currently executing Jasmine 2 test and the code to send an approval to the approval server
  • app/test-helpers/heredoc.js – a heredoc function to allow for easy specification of multi-line markup
  • app/test-helpers/directives.js – the test code that compiles the directive, cleans it up for a nice diff and passes it to be verified

Notable bits

Style guide

If you are curious about why I wrote my Angular code the way I have it’s because I’m following John Papa’s AngularJS style guide, which I think is very good and greatly improves maintainability of the resulting code.

Taming karma

I managed to get the following working for Karma:

  • Watch build that runs tests whenever a file changes – see the karma:watch and dev tasks
  • Default build including tests – see the karma:myApp and default tasks
  • A build that pops up a Chrome window to allow for debugging – see the karma:debug and debugtests takss

Simultaneous approval server runs

I managed to allow for the dev task to be running while running default by including the isPortTaken code to determine if the approvals server port is already taken.

Side note: if you are using this code across multiple projects consecutively then be careful because the approval server might be running from the other project. A way to avoid this would be to change the port per project (in both gruntfile.js and approvals.js.

Improved approval performance on Windows

I found that the performance of the approvals library was very slow on Windows, but with some assistance from the maintainers I worked out what the cause was and submitted a pull request. The version in npm has been updated, but there are currently no updates to approvals-server to use it. To overcome this I have used the npm-shrinkwrap.json file to override the version of the approvals library.

Get currently running test name in Jasmine 2

I wanted the approval test output file to be automatically derived from the currently-running test name (similar to what happens on .NET). It turns out that is a lot harder to arhieve in Jasmine 2, but with some Googling/StackOverflowing I managed to get it working as per the code in the approvals.js file.

Cleaning up the output markup for a good diff

AngularJS leaves a bunch of stuff in the resulting markup such as HTML comments, superfluous attributes and class names, etc. In order to remove all of this so the approved file is clean and in order to ensure the whitespace in the output is both easy to read and the same no matter what browser is being used I apply some modifications to the markup as seen in directives.js.

Easily specifying multi-line test markup

I pulled in a heredoc function I found on StackOverflow as seen in heredoc.js and used in the example test, e.g.:

DirectiveFixture.verify(heredoc(function () {/*    
    <myapp-display-products category="car" product="car">
        <div>{{car.name}}</div>
    </myapp-display-products>
*/}));

This is much nicer than having to concatenate one stirng per line or append a \ character at the end of each line, both of which aren’t handled nicely by the IDE I’m using.

 

Announcing TestStack.Dossier library

I’m pleased to announce the addition of a (somewhat) new library to the TestStack family called TestStack.Dossier. I say somewhat new because it’s a version 2 of an existing library that I published called NTestDataBuilder. If you hadn’t already heard about that library here is the one liner (which has only changed slightly with the rename):

TestStack.Dossier provides you with the code infrastructure to easily and quickly generate test fixture data for your automated tests in a terse, readable and maintainable way using the Test Data Builder, anonymous value and equivalence class patterns.

The release of TestStack.Dossier culminates a few months of (off and on) work by myself and fellow TestStacker Michael Whelan to bring a range of enhancements. The library itself is very similar to NTestDataBuilder, but there are some minor breaking changes. I decided to reduce confusion by keeping the version number consistent between libraries so TestStack.Dossier starts at version 2.0.

So why should I upgrade to v2 anyway?

There is more to TestStack.Dossier v2 than just a name change, a lot more. I’ve taken my learnings (and frustrations) from a couple of years of usage of the library into account to add in a bunch of improvements and new features that I’m really excited about!

Side note: my original post on combining the test data builder pattern with the object mother pattern and follow-up presentation still holds very true – this combination of patterns has been invaluable and has led to terser, more readable tests that are easier to maintain. I still highly recommend this approach (I use NTestDataBuilder TestStack.Dossier for the test data builder part).

Anonymous value support

As explained in my anonymous variables post (TBW(ritten) – future proofing this post, or setting myself up for disappointment :P) in my automated testing series, the use of the anonymous variable pattern is a good pattern to use when you want to use values in your tests whose exact value isn’t significant. By including a specific value you are making it look like that value is important in some way – stealing cognitive load from the test reader while they figure out the value in fact doesn’t not matter.

This is relevant when defining a test data builder because of the initial values that you set the different parameters to by default. For instance, the example code for NTestDataBuilder on the readme had something like this:

class CustomerBuilder : TestDataBuilder<Customer, CustomerBuilder>
{
    public CustomerBuilder()
    {
        WithFirstName("Rob");
        WithLastName("Moore");
        WhoJoinedIn(2013);
    }

    public CustomerBuilder WithFirstName(string firstName)
    {
        Set(x => x.FirstName, firstName);
        return this;
    }

    ...
}

In that case the values "Rob", "Moore" and 2013 look significant on initial inspection. In reality it doesn’t matter what they are; any test where those values matter should specify them to make the intent clear.

One of the changes we have made for v2 is to automatically generate an anonymous value for each requested value (using Get) if none has been specified for it (using Set). This not only allows you to get rid of those insignificant values, but it allows you to trim down the constructor of your builder – making the builders terser and quicker to write.

Given we aren’t talking about variables but rather values I have thus named the pattern anonymous values rather than anonymous variables.

There are a number of default conventions that are followed to determine what value to use via the new Anonymous Value Fixture class. This works through the application of anonymous value suppliers – which are processed in order to determine if a value can be provided and if so a value is retrieved. At the time of writing the default suppliers are the following (applied in this order):

  • DefaultEmailValueSupplier – Supplies an email address for all string properties with a property name containing email
  • DefaultFirstNameValueSupplier – Supplies a first name for all string properties with a property name containing firstname (case insensitive)
  • DefaultLastNameValueSupplier – Supplies a last name for all string properties with a property name containing lastname or surname (case insensitive)
  • DefaultStringValueSupplier – Supplies the property name followed by a random GUID for all string properties
  • DefaultValueTypeValueSupplier – Supplies an AutoFixture generated value for any value types (e.g. int, double, etc.)
  • DefaultValueSupplier – Supplies default(T)

This gets you started for the most basic of cases, but from there you have a lot of flexibility to apply your own suppliers on both a global basis (viaAnonymousValueFixture.GlobalValueSuppliers) and a local basis for each fixture instance (via fixture.LocalValueSuppliers) – you just need to implement IAnonymousValueSupplier. See the tests for examples.

Equivalence classes support

As explained in my equivalence classes and constrained non-determinism post (TBW) in my automated testing series the principle of constrained non-determinism frees you from having to worry about the fact that anonymous values can be random as long as they fall within the equivalence class of the value that is required for your test.

I think the same concept can and should be applied to test data builders. More than that, I think it enhances the ability for the test data builders to act as documentation. Having a constructor that reads like this for instance tells you something interesting about the Year property:

class CustomerBuilder : TestDataBuilder<Customer, CustomerBuilder>
{
    public CustomerBuilder()
    {
        WhoJoinedIn(Any.YearAfter2001());
    }

    ...
}

You may well use value objects that protect and describe the integrity of the data (which is great), but you can still create an equivalence class for the creation of the value object so I still think it’s relevant beyond primitives.

We have some built-in equivalence classes that you can use to get started quickly for common scenarios. At the time of writing the following are available (as extension methods of the AnonymousValueFixture class that is defined in a property called Any on the test data builder base class):

  • Any.String()
  • Any.StringMatching(string regexPattern)
  • Any.StringStartingWith(string prefix)
  • Any.StringEndingWith(string suffix)
  • Any.StringOfLength(int length)
  • Any.PositiveInteger()
  • Any.NegativeInteger()
  • Any.IntegerExcept(int[] exceptFor)
  • Any.Of<TEnum>()
  • Any.Except<TEnum>(TEnum[] except)
  • Any.EmailAddress()
  • Any.UniqueEmailAddress()
  • Any.Language()
  • Any.FemaleFirstName()
  • Any.MaleFirstName()
  • Any.FirstName()
  • Any.LastName()
  • Any.Suffix()
  • Any.Title()
  • Any.Continent()
  • Any.Country()
  • Any.CountryCode()
  • Any.Latitude()
  • Any.Longitude()

There is nothing stopping you using the anonymous value fixture outside of the test data builders – you can create a property called Any that is an instance of the AnonymousValueFixture class in any test class.

Also, you can easily create your own extension methods for the values and data that makes sense for your application. See the source code for examples to copy. A couple of notes: you have the ability to stash information in the fixture by using the dynamic Bag property and you also have an AutoFixture instance available to use via Fixture.

Side note: I feel that Dossier does some things that are not easy to do in AutoFixture, hence why I don’t “just use AutoFixture” – I see Dossier as complimentary to AutoFixture because they are trying to achieve different (albeit related) things.

A final note: I got the idea for the Any.Whatever() syntax from the TDD Toolkit by Grzegorz Gałęzowski. I really like it and I highly recommend his TDD e-book.

Return Set rather than this

This is a small, but important optimisation that allows test data builders to be that little bit terser and easier to read/write. The Set method now returns the builder instance so you can change your basic builder modification methods like in this example:

// Before
public CustomerBuilder WithLastName(string lastName)
{
    Set(x => x.LastName, lastName);
    return this;
}

// After
public CustomerBuilder WithLastName(string lastName)
{
    return Set(x => x.LastName, lastName);
}

Amazingly terse list of object generation

This is by far the part that I am most proud of. I’ve long been frustrated (relatively speaking, I thought what I had in the first version was very cool and useful) with the need for writing the lambda expressions when building a list of objects, e.g.:

var customers = CustomerBuilder.CreateListOfSize(3)
    .TheFirst(1).With(b => b.WithFirstName("Robert").WithLastName("Moore))
    .TheLast(1).With(b => b.WithEmail("matt@domain.tld"))
    .BuildList();

I always found tha the need to have the With made it a bit more verbose than I wanted (since it was basically noise) and I found that needing to write the lambda expression slowed me down. I dreamed of having a syntax that looked like this:

var customers = CustomerBuilder.CreateListOfSize(3)
    .TheFirst(1).WithFirstName("Robert").WithLastName("Moore")
    .TheLast(1).WithEmail("matt@domain.tld")
    .BuildList();

Well, one day I had a brainwave on how that may be possible and I went and implemented it. I won’t go into the details apart from saying that I used Castle Dynamic Proxy to do the magic (and let’s be honest it’s magic) and you can check out the code if interested. I’m hoping this won’t come back to bite me, because I’ll freely admit that this adds complexity to the code for creating lists; you can have an instance of a builder that isn’t an instance of a real builder, but rather a proxy object that will apply the call to part of a list of builders (see what I mean about complex)? My hope is that the simplicity and niceness of using the API outweighs the confusion / complexity and that you don’t really have to understand what’s going on under the hood if it “just works”TM.

If you don’t want to risk it that’s fine, there is still a With method that takes a lambda expression so you can freely avoid the magic.

The nice thing about this is I was able to remove NBuilder as a dependency and you no longer need to create an extension method for each builder to have a BuildList method that doesn’t require you to specify the generic types.

Why did you move to TestStack and why is it now called Dossier?

I moved the library to TestStack because it’s a logical fit – the goal that we have at TestStack is to make it easier to perform automated testing in the .NET ecosystem – that’s through and through what this library is all about.

As to why I changed the name to Dossier – most of the libraries that we have in TestStack have cool/quirky names that are relevant to what they do (e.g.Seleno, Bddfy). NTestDataBuilder is really boring so with a bit of a push from my colleagues I set about to find a better name. I found Dossier by Googling for synonyms of data and out of all the words dossier stood out as the most interesting. I then asked Google what the definition was to see if it made sense and low and behold, the definition is strangely appropriate (person, event, subject being examples of the sorts of objects I tend to build with the library):

a collection of documents about a particular person, event, or subject

Mundane stuff

The GitHub repository has been moved to https://github.com/TestStack/TestStack.Dossier/ and the previous URL will automatically redirect to that address. I have released an empty v2.0 NTestDataBuilder release to NuGet that simply includes TestStack.Dossier as a dependency so you can do anUpdate-Package on it if you want (but will then need to address the breaking changes).

If you have an existing project that you don’t want to have to change for the breaking changes then feel free to continue using NTestDataBuilder v1 – for the featureset that was in it I consider that library to be complete and there weren’t any known bugs in it. I will not be adding any changes to that library going forward though.

As usual you can grab this library from NuGet.