Monday, 11 February 2019

Find where an object is unintentionally being converted to a string

I've been applying the Replace Primitive with Object pattern to a code base - changing what used to be strings into a custom type (which not only makes the code more readable, but now ensures through type safety that you can't accidentally pass in any old random values to methods that used to just take strings.

The code has tests, and after applying the refactoring, I have a failing test - which hints that somewhere there's an implicit conversion from the new strongly typed object back to a string. The test's failing assertion says it received "MyNamespace.TypedThing" (which is what the default implementation of ToString() returns), rather than the wrapped string value that TypedThing encapsulates.

My initial suspicion is that there's probably code similar to this that's causing the problem:

TypedThing thing = new TypedThing("thingy"); 
string s = $"{thing}";

ReSharper has a cool utility - "Structural Search and Replace". Unfortunately it doesn't work for single expressions like "{thing}".

If I was cluey, I might be able to write a Roslyn tool to search the code and find instances like that, but that's going to take a bit more effort than I want.

What about this: temporarily override the ToString() method on my custom type, and make it throw an exception!

It's a bit of a sledgehammer, but it worked!

As it turns out my suspicion was not quite correct. The offending code was actually assigning the custom type to an Object type (which explains the lack of compiler type warnings), which later on must be converted to a string.

Now that I could see an example, I could use ReSharper's SSR to confirm that was the only instance of that kind of assignment (SSR can be used as I'm searching for an assignment statement, not just a single expression). Just for good measure, I'll also re-run the entire test suite to make sure there aren't any other similar problems still hiding.

Sunday, 3 February 2019

Choco list -localonly (Feb 2019 Edition)

What software / applications am I using on my laptop (February 2019 Edition) according to Chocolatey? Here's an edited list of the output from choco list -localonly:

audacity2.3.0Audio editor
becyicongrabber2.30.0.20161027Icon extractor (for creating Chocolatey packages)
beyondcompare4.2.9.23626My favourite file comparison tool
beyondcompare-integration1.0.1Configure Beyond Compare for TortoiseGit/Svn
dellcommandupdate-uwp3.0.0Dell's driver update app
dns-benchmark1.3.6668.0Useful DNS checker
dotnetdeveloperbundle2.3.0.2563RedGate's .NET tools
FiraCode1.206Nice developer font
keepass2.41Password manager
mousewithoutborders2.1.8.105Share mouse across laptop and desktop PCs
notepadplusplus7.6.3Using this less now compared to VS Code
obs-studio22.0.2Video / screen recording
PDFXchangeEditor7.0.328.2My favourite
Pester4.4.1PowerShell unit tests
pingplotter5.8.10Useful visual ping network status
procmon3.50SysInternals Process Monitor
resharper-clt.portable2018.3.2ReSharper's free command-line tools
screentogif2.16Handy screen recorder
snagit2019.1.0Screen grabber
tailblazer0.9.0.536Text/log file viewer
ubiquiti-unifi-controller5.9.29Software for managing UniFi wireless access points
vagrant2.2.3Manage virtual machines
vsts-cli0.1.4.20190126Command line tool for managing Azure DevOps
windirstat1.1.2.20161210Where's all that disk space being used?
x-lite5.4.0.94388VoIP client
zoomit4.50.0.20160210Great for presentations

This is also a good basis for refreshing my Boxstarter scripts.

Sunday, 27 January 2019

TimeoutException (aka Tour Down Under 2019 and a week off)

Back at work for a couple of weeks of 2019 and I don't want to rush things too much, so I organised to take an extra week off after this year's Tour Down Under bike ride.

David, his son and his dad after completing the TDU
Last year's community ride (the 'Challenge Tour') had to be cancelled due to hot weather. We've had our share of hot weather again this year, but fortunately Saturday (previously Friday) turned out to be ideal. This year I rode with my dad and my son - 3 generations of Gardiners! Very proud of my son, who completed the 100km distance (his furthest ridden) plus (impressing a lot of our fellow riders) he did it on a mountain bike (as he doesn't have a road bike).

I didn't need the week off to recuperate from the ride - instead I was catching up with relatives visiting Adelaide! It was great to see them lots of time during the week.

We all just made it through the 46.6°C record maximum temperature for Adelaide on Thursday (that was a really, really hot day).
A ropes course
I watched as my son and his cousin did the ropes course at West Beach

Vanilla slice

French monopoloy game board
French Monopoly - Relying on my niece to translate

I'm finishing off the mini-break with the Australia Day long weekend. Caught up with the visiting rellies one last time (before they flew home) for morning tea/lunch/kicking the footy in the park (how Aussie is that!) following by dinner with my folks. A really nice day!

Sunday, 13 January 2019

Installing .NET Core SDK for Azure Pipelines builds

How do you ensure that the correct version of .NET Core SDK is installed for your Azure Pipeline builds? You could install it manually on your build agents, but wouldn't it be better to automate it?

The .NET Core Tool Installer Task can be used for this, and if you don't change the version of the SDK that you require frequently, very often that's enough.

When you're developing .NET Core applications, you can indicate which version of the SDK you require to build with by using a global.json file.

Unfortunately, the Installer Task doesn't currently know about global.json, so you might feel like you're doubling up - specifying the required version not only in that file but also in the configuration of the Installer Task. Don't do that!

With a bit of PowerShell, that can be done.. Create a PowerShell Task that runs before the Installer task and use it to set a variable that can then be used by the following task(s).

If you're using YAML, the task definitions would look something like this:

- powershell: |
    $PathToGlobalJson = Join-Path -Path $Env:BUILD_SOURCESDIRECTORY -ChildPath "global.json"
    $GlobalJson = Get-Content -Raw -Path  $PathToGlobalJson | ConvertFrom-Json
    $Version= $GlobalJson.sdk.version
    Write-Host ("##vso[task.setvariable variable=SdkVersion;]$Version")
  displayName: 'Parse global.json'

- task: DotNetCoreInstaller@0
  displayName: 'Use .NET Core sdk $(SdkVersion)'
    version: '$(SdkVersion)'