Author Archives: Gerben

Starting a process in PowerShell with dynamic command-line parameters

Starting a command-line process from PowerShell is very easy. A simple java -jar helloworld.jar works just fine. However when I’m starting nodes in my Selenium Grid I need to dynamically create a different number of parameters. The following code will fail because the various strings wont be correctly mapped to the usual argv[] input parameters for the java.exe process:

$arguments = ''
$arguments += ' ' + '-jar xxxx.jar'
$arguments += ' ' + '-browser'
$arguments += ' ' + 'browserName=firefox,version=3.6,platform=WINDOWS'
$arguments += ' ' + '-browser'
$arguments += ' ' + 'browserName=internet explorer,version=10,platform=WINDOWS'
java $arguments

Instead, just create an array of command-line arguments like this (assume that $Capabilities is an array of hash tables)

        $arguments = @()
        $arguments += '-jar'
        $arguments += $Jar
        $arguments += '-role'
        $arguments += 'node'
        $arguments += '-port'
        $arguments += 5555
        $arguments += '-hub'
        $arguments += '"' + '' + '"'

        foreach ($hashTable in $Capabilities)
            $arguments += '-browser'
            $strCaps = ($hashTable.GetEnumerator() | ForEach-Object { '$($_.Key)=$($_.Value)' }) -join ','
            $strCaps = '"' + $strCaps + '"'
            $arguments += $strCaps
        java $arguments

What to do when SpecRun doesn’t find any testcases to execute

So you’ve installed SpecRun, updated app.config, started a testrun….but SpecRun reports that it found 0 testcases. There’s two fixes for this.

Regenerate the feature files

Usually the *.feature.cs code-behinds aren’t removed when you clean the project. Those files still contain code pertaining to the previous test runner. You need to regenerate the .feature files in the solution before the code-behinds are updated to use the SpecRun test runner.

Clean Visual Studio’s cache for the test runners

Another cause for this unexpected behavior is due due to corruption in Visual Studio’s cache for the test runners. This can be fixed by the following:

  1. Close Visual Studio
  2. navigate to %TEMP%\VisualStudioTestExplorerExtensions\
  3. Delete any SpecRun related folders

How to get video recordings of your testcase

Recording the screen during test execution is very helpful in diagnosing issues. Here are a few ways you can achieve this.

Visual Studio’s Data Diagnostic Adapters

If you’re running your tests with Visual Studio and/or Test Controller/Agents, then you can add a .testsettings file to the test project and configure it to include the “Video Data Diagnostic Adapter” That will record the screen while each testcase is executing and save the results in the output directory specified in the .testsettings file. I find this to be very useful when I’m authoring new testcases on my machine or when I’m running through a Controller/Agent for an app that interacts with the desktop.

Selenium Grid Servlets

If you’re running on a Selenium Grid setup, then there are various ways of getting the nodes to record the screen. Take a look at Tuenti VideoRecorderService or Selenium Video Node.

Screen recording software

You can use some kind of screen recording software like Camstudio or VNC. For me this isn’t preferred as it requires manual action on behalf of the tester.

Single Sign On with Selenium and Firefox in a windows environment

When you run a testcase using Selenium WebDriver against a site like SharePoint, you’ll frequently see that Firefox is blocked waiting for you to enter the username and password of a user. This may seem unexpected because it even happens when your own Firefox window doesn’t need you to enter any credentials.

The reason for this is because the FirefoxDriver creates a new temporary profile and it doesn’t include the settings needed for SSO. There’s 2 ways of dealing with this.

The first way

The first way only works on the local machine that is running the tests. You can configure the FirefoxDriver to use an existing profile instead of creating a new one. The following code snippet shows how to do that in C#.

new FirefoxDriver(new FirefoxProfileManager().GetProfile("default"));

You don’t have to use the “default” profile. You’re free to create a dedicated profile for Selenium tests if you want. Just start Firefox from the command line using firefox -p to start Firefox’s Profile Manager.

The second way

The first way wont work if your tests use RemoteWebDriver to connect to a remote instance of FirefoxDriver. This is due to the fact that identically named profiles, still have a different internal name on each machine.

Instead we will configure Firefox to include the relevant SSO settings into every profile that’s created. You will need administrative credentials during this one-time configuration. Lets assume your site is called “https://myserver.contoso.local/sites/myapp”

  1. Open Windows Explorer and navigate to the Firefox installation directory. That’s usually “C:\Program Files (x86)\Mozilla Firefox”
  2. Create a file there (in this example, I used “mozilla.cfg”) with the following content:
    lockPref("network.automatic-ntlm-auth.trusted-uris", "contoso.local");
  3. Use Windows Explorer to navigate to Firefox’s directory containing the preferences to be used for new profiles. That’s usually “C:\Program Files (x86)\Mozilla Firefox\defaults\pref”
  4. Create a file there called “local-settings.js” with the following content:
    //@line 2 "c:\builds\moz2_slave\rel-m-esr31-w32_bld-0000000000\build\browser\app\profile\channel-prefs.js"
    /* This Source Code Form is subject to the terms of the Mozilla Public
    * License, v. 2.0. If a copy of the MPL was not distributed with this
    * file, You can obtain one at */
    pref("general.config.obscure_value", 0);
    pref("general.config.filename", "mozilla.cfg");

See Locking preferences in Firefox for details on this.

Fixing the slow combination of WebDriver and Internet Explorer.

Is your Selenium WebDriver running very slowly with Internet Explorer? Then you’re probably running a 64-bit IEDriverServer.exe with a 32 bit Internet Explorer. Even on 64-bit systems, Windows usually runs the 32-bit iexplore.exe.To solve the problem, just replace your IEDriverServer.exe with the 32 bit one and the speed increase will be enormous.

Describing large forms and data entry in Cucumber / SpecFlow feature files

Did you know that in .feature files you can use the table notation to specify each field and value in rows instead of columns?

This can make the file way more readable when a step needs a lot of different parameters. Here is an example that shows both ways of creating an invoice:

Feature: Demo

Scenario: TwoDifferentStylesOfSteps
	When I create an invoice with number '111' with '119.00' euro total, '19.00' euro VAT from 'ACME Inc' at '1234XYZ 99' in 'USA'
	When I create the following invoice:
		| Field            | Value      |
		| Number           | 222        |
		| TotalAmount      | 238.00     |
		| VATAmount        | 38.00      |
		| Debtor           | ACME Inc   |
		| DebtorAdresLine1 | 1234XYZ 99 |
		| DebtorCountry    | USA        |
	Then The systems invoice store must look like this:
		| Number | TotalAmount | VatAmount |
		| 111    | 119.00      | 19.00     |
		| 222    | 238.00      | 38.00     |

Here is the corresponding binding code:

namespace TableExample
    public class Invoice
        public int Number { get; set; }
        public decimal TotalAmount { get; set; }
        public decimal VatAmount { get; set; }
        public string Debtor { get; set; }
        public string DebtorAdresLine1 { get; set; }
        public string DebtorAdresLine2 { get; set; }
        public string DebtorCountry { get; set; }
    public class TablesSteps
        private IList<Invoice> Invoices;

        public TablesSteps()
            this.Invoices = new List<Invoice>();

        [When(@"I create an invoice with number '(.*)' with '(.*)' euro total, '(.*)' euro VAT from '(.*)' at '(.*)' in '(.*)'")]
        public void WhenICreateAnInvoiceWithNumberWithEuroTotalEuroVATFromAtIn(int Number, 
            decimal TotalAmount,
            decimal VatAmount,
            string Debtor,
            string DebtorLine1,
            string DebtorCountry)
            Invoice TestInvoice = new Invoice();
            TestInvoice.Number = Number;
            TestInvoice.TotalAmount = TotalAmount;
            TestInvoice.VatAmount = VatAmount;
            TestInvoice.Debtor = Debtor;
            TestInvoice.DebtorAdresLine1 = DebtorLine1;
            TestInvoice.DebtorCountry = DebtorCountry;

        [When(@"I create the following invoice:")]
        public void WhenICreateTheFollowingInvoice(Table table)
            Invoice TestInvoice = table.CreateInstance<Invoice>();

        [Then(@"The systems invoice store must look like this:")]
        public void ThenTheSystemsInvoiceStoreMustLookLike(Table table)
            var rows = table.CreateSet<Invoice>();
            foreach (Invoice test in rows)
                IEnumerable<Invoice> Matches = this.Invoices
                    .Where(invoice => invoice.Number.Equals(test.Number))
                    .Where(invoice => invoice.TotalAmount.Equals(test.TotalAmount))
                    .Where(invoice => invoice.VatAmount.Equals(test.VatAmount));
                Assert.AreEqual(1, Matches.Count(), string.Format("Invoice {0} not correct in invoicestore", test.Number));



My Definition of Done for performance and loadtest cases

Load and performance testcases are frequently used for multiple objectives:

  • Determining where a system’s breaking point is
  • Determining if a system is able to meet a required load

Here are the criteria I use to make sure my load/performance testcases are good enough to use and maintain for all the objectives. I’ve been using this for regular load tests on a huge SharePoint farm at one of my clients.

Criteria Explanation
The following information is parametrized into context parameters:

  1. Server name(s)

  2. Site name(s)

  3. List/library/page name(s)

  4. Filenames (up- and download) specific to the testcase

User credentials are included in the testcase
Think-times on the various requests are configured conform test design I always check that the agreed thinktimes are present. I configure the loadtest to either use them all or ignore them all
The testcase includes a transaction encapsulating only the requests relevant to the scenario Test results always state how fast pages are. However, we also want to see fast the system is able to respond to user scenarios that include multiple requests
Testcase has logic to fail if generic errors / messages are returned
Testcase has logic to fail if the correct content has not been returned A simple validation rule to check for a specific string in the output is usually enough
Testcase has logic determine if a performance threshold has been exceeded
The decision to fail the testcase based on the threshold, can be enabled or disabled without changing the testcase I usually include a ‘responsetime goal’ validation rule and set its level to Low or Medium. Then at runtime, I can indicate what level of validation rules should apply to the entire loadtest. That will allow me to run the entire loadtest to stress the farm without a few performance delays causing the run to fail
Testcase is able to run standalone or as part of a loadtest with concurrent users
The testcase should only delete or modify information that it owns. If this is not possible, then the testcase must gracefully accepts errors when concurrent instances of it touch that information
Testcases that create, modify or delete information must include information that uniquely identifies the specific instance of the testcase In practice I use the following combination concatenated into a string:

  1. The id of the virtual user (WebTestUserId)

  2. The id of the iteration (WebTestIteration)

  3. The id of the agent running the test (AgentName)

Testcases conform to the testdesign in their decision to parse and execute dependent requests (.css, .js, images etc etc)

How to generate self signed certificates

Sometimes you need a self-signed certificate for the purpose of testing websites or digitally signing files such as PDFs. Your PDF software will probably ask you for a .pfx file. You can generate these on Windows, Mac or linux

On Windows

On windows, with Visual Studio, you can use the makecert utility:

cd "C:\Program Files (x86)\Microsoft SDKs\Windows\v7.1A\Bin\"
.\makecert.exe -r -a sha512 -len 4096 -pe -sv c:\users\gerben\documents\example.key -n "CN=Test" c:\users\gerben\documents\example.cer
.\pvk2pfx.exe -pvk c:\users\gerben\documents\example.key -spc c:\users\gerben\documents\example.cer -pfx c:\users\gerben\documents\example.pfx -po PasswordForPfxFile

Linux and Mac

Most linux and OSX machines have openssl installed by default. You can generate the various files as follows:

commandprompt> openssl req -x509 -nodes -days 365 -newkey rsa:1024 -keyout example.key -out example.pem -subj "/C=NL/O=Tester/"
commandprompt> openssl pkcs12 -export -out example.pfx -inkey example.key -in example.pem 
#openssl will ask you for a password. Don't forget it

This will output the following:

File Description
example.key Your private key.
example.pem The certificate. This also contains your public key
example.pfx An encrypted, password protected file that contains both your private and public key

You can see your public key with the following command:

commandprompt> openssl x509 -in example.pem -pubkey
-----END PUBLIC KEY-----

You can see the contents of your certificate using the following command:

commandprompt> openssl x509 -in example.pem -text
        Version: 3 (0x2)
        Serial Number:
        Signature Algorithm: sha1WithRSAEncryption
        Issuer: C=NL, O=Tester,
            Not Before: Apr 16 12:52:39 2015 GMT
            Not After : Apr 15 12:52:39 2016 GMT
        Subject: C=NL, O=Tester,
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
            RSA Public Key: (1024 bit)
                Modulus (1024 bit):
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Subject Key Identifier: 
            X509v3 Authority Key Identifier: 

            X509v3 Basic Constraints: 
    Signature Algorithm: sha1WithRSAEncryption

Entity Framework Code First migrations and the [StringLength] annotation

Recently I needed to change my model so that a field would be checked for uniqueness. I eagerly added the [StringLength(3)] and [Index(IsUnique = true)] annotations to the model and ran Add-Migration and Update-Database. Close, but no cigar unfortunately. Update-Database kept throwing the following error: System.Data.SqlClient.SqlException (0x80131904): Column 'IsoCode' in table 'dbo.CurrencyModels' is of a type that is invalid for use as a key column in an index.

This is due to the fact that the generated code migration, was only applying the index and not the length restriction. You can fix this directly in the Up() and Down() methods of the code migration by using AlterColumn() as follows:

    public partial class UniqueCurrency : DbMigration
        public override void Up()
            AlterColumn("dbo.CurrencyModels", "IsoCode", c => c.String(maxLength: 3));
            CreateIndex("dbo.CurrencyModels", "IsoCode", unique: true);
        public override void Down()
            AlterColumn("dbo.CurrencyModels", "IsoCode", c => c.String(maxLength: null));
            DropIndex("dbo.CurrencyModels", new[] { "IsoCode" });