Up until now in this chapter, we have been performing simple customizations that make it much easier for users to work in TFS. The next part that we are going to explore in Web Access is creating a basic JavaScript plugin that will display work item IDs on both the task and portfolio boards and the state of requirements on the task board.
Note
The JavaScript API for TFS is not an official extension point, meaning that it is not supported by Microsoft (this will not affect your TFS installation support) and does change between versions at which point your plugin could break. Normally, minor changes are required to your plugin to get it up and running. But still it is worth testing all plugins in a staging environment before applying them to a production environment where they may not work and then potentially break other functionality.
I prefer to use TypeScript as much as possible over raw JavaScript as it gives you many benefits that make it easier to prevent...