Codespaces: Fix launching all-sample app, add auto sample discovery

[Arlodotexe]

This PR

• Splits Project Reference generation into a new DiscoverSamples.ps1 file
• Fixes launching all-sample app from the dropdown in VS
• Adds automatic discovery of individual sample projects for launch.json.
• Closes Codespaces can't find SampleRefs.props #89

Demos:

All-Samples-In-Codespaces-1.mp4

Sample-Discovery-Codespaces-1.mp4

[michael-hawker]

Did we want to add this command as a separate job on the CI?

[Arlodotexe]

I didn't include in this PR because it isn't as easy as running a command in the CI.

To do this proper, we'd want to

1. Investigate if we can validate the JSON as a VSCode config using some command line tool (make sure invalid json isn't generated or committed)
2. Write a script to copy the command and parameters programmatically by reading the JSON file, then execute it to make sure it does fail.
3. Repeat step 1 and 2 with the generated "discovered" sample launch configs.

[michael-hawker]

Rebased on top of main to grab the changes from #85

[michael-hawker]

Does this work if the script is executed from a different directory? (Don't think that'll be a common occurrence, but curious as I know I had to use a different method in the past to grab the current directory of where the script was located that is being executed.)

[Arlodotexe]

I don't think this would work if ran from a different directory, same way relatives paths break in UseUnoWinUI.ps1 and UseTargetFrameworks.ps1 when run from the wrong directory.

[michael-hawker]

When running the all solution - Looks like the docs are adding more to the path in Codespaces (this worked in VS Code locally last I checked for WASM):

The files themselves are in the expected location (same as they are locally). So it looks like it may be the source generator output itself. (Tested a single experiment and that's working properly for the CS/XAML files to display the individual samples, but still fails on the doc with the same incorrect path.)

Added the generated output from the SG to investigate (@mrlacey I had to add the EmitCompilerGeneratedFiles to the Labs.Sample.props not the Labs.Head.props to see then), but that shows the wrong path here:

FilePath = @"/workspaces/Labs-Windows/labs/CanvasLayout/samples/CanvasLayout.Sample/canvaslayout.md"

I suspect this is Windows vs. Linux slashes, will try that quick with the string array for the split and see what happens.

[Arlodotexe]

When running the all solution - Looks like the docs are adding more to the path in Codespaces (this worked in VS Code locally last I checked for WASM):

Did a quick test in a Codespace on main (manually running the build command since launch.json is broken there), looks like this issue is an uncaught problem with #85 and not related to this PR.

@michael-hawker Is this a prerequisite for merging this, could we do this in another PR? Since this PR is only related to launching in a codespace and sample discovery for the VSCode dropdown, we should be good to go?

[michael-hawker]

@Arlodotexe it's a one-line fix, so I'll add it. I did see this trying to run Discover Samples directly:

(If I ran the all samples instead first then it ran the generate solution and then discover samples fine...)

After installing the powershell extension I got this:

[Arlodotexe]

@Arlodotexe it's a one-line fix, so I'll add it. I did see this trying to run Discover Samples directly:

That's so strange, I did this entire PR in a codespace. I'll test again with a fresh container and see if I can repro.

[michael-hawker]

Still some known and unknown hiccups with how Codespaces works, but everything here looking good now, thanks!