Test call hierarchy ui

[jrieken]

Refs: #16110

• any @bpasero
• any @weinand

Complexity: 2

VS Code has now UI to show a call hierarchy. A call hierarchy shows all callers or calls of a function. It allows to drill into the call chain, e.g. showing callers of callers or calls of calls. This is item about testing the UX.

➡️ The challenge is that no real extension providing call hierarchy data exists. You can use this sample: https://github.com/jrieken/demo-callhierarchy. To get started (1) clone & npm install, (2) F5, and (3) open sample/test.ts

Apart from the data quality there are things to test. Make sure that

• you have a context menu entry "Call Hierarchy" with a keyboard shortcut
• you have a command palette entry
• call hierarchy shows a peek view, similar to 'peek references'
• the tree shows the call graph and the editor shows a preview of the calls
• the title shows a breadcrumb-like path to the current caller/call
• the title allows to toggle the direction, e.g. 'Calls To' and 'Calls From'
• everything is keyboard accessible and "feels right"
• you can double click inside the embedded editor to get there