Partial Build
It should be relatively simple to get the list of touched files/folders from a PR. Then, if the touched folders all match the pattern of something like ^(legacy|release|experimental)/([a-z]+)/(\2)[a-z0-9_]+ -- that is, the expected folder layout -- run the build only on the touched folders.
If any other files are touched, run a full build, because the PR may include tooling updates etc.
Note 1: deletions or modifications to release/shared or experimental/shared would also require a full build. New files in those folders can only be referenced by changes to a package, so we don't need to do a full build if only new files are found there.
Note 2: release/packages would require a full build of release/
GitHub Action
Second part to this is to do this in a GHA so that the build can run automatically on the contributor's account, avoiding the need to involve TC build altogether.
Partial Build
It should be relatively simple to get the list of touched files/folders from a PR. Then, if the touched folders all match the pattern of something like
^(legacy|release|experimental)/([a-z]+)/(\2)[a-z0-9_]+-- that is, the expected folder layout -- run the build only on the touched folders.If any other files are touched, run a full build, because the PR may include tooling updates etc.
Note 1: deletions or modifications to release/shared or experimental/shared would also require a full build. New files in those folders can only be referenced by changes to a package, so we don't need to do a full build if only new files are found there.
Note 2: release/packages would require a full build of release/
GitHub Action
Second part to this is to do this in a GHA so that the build can run automatically on the contributor's account, avoiding the need to involve TC build altogether.