## Changes
The CLI test runner instantiates a new CLI "instance" through
`cmd.New()` and runs it with specified arguments. This is as close as we
get to running the real CLI **in-process**. This runner was located in
the `internal` package next to other helpers. This change moves it to
its own dedicated package.
Note: this runner transitively imports pretty much the entire
repository, which is why we intentionally keep it _separate_ from
`testutil`.
## Tests
n/a
## Changes
This combination of changes allows pretty-printing errors happening
during the "load" and "init" phases, including their locations.
Move to render code into a separate module dedicated to rendering
`diag.Diagnostics` in a human-readable format. This will be used for the
`bundle deploy` command.
Preserve the "bundle" value if an error occurs in mutators. Rewrite the
go templates to handle the case when the bundle isn't yet loaded if an
error occurs during loading, that is possible now.
Improve rendering for errors and warnings:
- don't render empty locations
- render "details" for errors if they exist
Add `root.ErrAlreadyPrinted` indicating that the error was already
printed, and the CLI entry point shouldn't print it again.
## Tests
Add tests for output, that are especially handy to detect extra newlines
## Changes
List available targets when incorrect target passed
## Tests
```
andrew.nester@HFW9Y94129 wheel % databricks bundle validate -t incorrect
Error: incorrect: no such target. Available targets: prod, development
```
Pieter Noordhuis
Gleb Kanterov
Andrew Nester