Move baselines out of source generator tests

[jjonescz]

Follow up on #8242 (comment).

[333fred]

So, I honestly, truly prefer the test output inline with the test, as I find it makes reviewing significantly easier. Am I the only one? I'm willing to concede if so, but if not, I'd much rather keep the current structure, even if it's inconsistent with some of the other test projects. @dotnet/razor-compiler for opinions.

[jjonescz]

it makes reviewing significantly easier

I can see that. But there are also disadvantages:

• the inline baselines cannot be automatically updated (unless we write a tooling for that); that means lots of manual copy-pasting (Razor codegen updates tend to change lots of baselines - albeit we can mitigate that by having less baselines in tests in general),
• the test files can grow large which makes them harder to navigate around.

[chsienki]

So I was the one who originally put these in code. Like @333fred I prefer having it in the test so you can easily see the behaviour inline with the test.

However, I'm extremely sympathetic to the point that it makes the tests unwieldy, and it would definitely be nice to be able to update the baselines rather than having to do it manually.

[jjonescz]

However, I'm extremely sympathetic to the point that it makes the tests unwieldy, and it would definitely be nice to be able to update the baselines rather than having to do it manually.

Perhaps we can do that even if they are in source, using Roslyn, or something like https://github.com/jjonescz/roslyn-test-updater. Closing this for now.