Leveraging IntelliSense for Azure DevOps YAML Pipelines in Visual Studio Code

If you're building out YAML pipelines for Azure DevOps (ADO) and don't wish to hand roll them in the online editor provided, you can instead build them in Visual Studio Code. The 1st thing you'll be hunting down though is IntelliSense and auto-complete assistance for your .yml pipeline code. Out-of-the-box, VSC doesn't have this support other than generic YAML language services so you'll want an extension. There is an extension for this and name of it is simply, 'Azure Pipelines' which can be found in the Marketplace. 

The issue is the Microsoft extension for the ADO pipelines is poorly rated at 2 out of 5 stars which made me wonder if it wasn't worth using. The good news is that rating isn't in reflection for a completely orphaned product as the latest commit was within a week of this writing. The main critique which I verified is after installation it just doesn't seem to do anything. However, with a single-step I got the primary functionality working as desired and have the IntelliSense and auto-complete features I needed.

The key is to manually switch the 'Language Mode' setting in the bottom-right hand corner to the proper value for the specific code file being created (or use the keyboard shortcut Ctrl + K M). Initially it will show 'YAML' which has been auto-detected, and in this mode none of the extension characteristics work. 

Click the dropdown and you'll get a selection of languages that can be set. Select, 'Azure Pipelines.'

Now the .yml file you're working on will have IntelliSense features, auto-complete, and hinting leveraging the installed extension which is helpful in creating pipelines.