The merge tool provides a way for configurations to determine the branches
for a label lazily. This is supported because it allows labels to respect
the currently selected base branch through the Github UI. e.g. if `target: label`
is applied on a PR and the PR is based on the patch branch, then the change
could only go into the selected target branch, while if it would be based on
`master`, the change would be cherry-picked to `master` too. This allows for
convenient back-porting of changes if they did not apply cleanly to the primary
development branch (`master`).
We want to expand this function so that it is possible to report failures if an
invalid target label is appplied (e.g. `target: major` not allowed in
some situations), or if the Github base branch is not valid for the given target
label (e.g. if `target: lts` is used, but it's not based on a LTS branch).
PR Close#38223
The merge script currently accepts a configuration function that will
be invoked _only_ when the `ng-dev merge` command is executed. This
has been done that way because the merge tooling usually relies on
external requests to Git or NPM for constructing the branch configurations.
We do not want to perform these slow external queries on any `ng-dev` command
though, so this became a lazily invoked function.
This commit adds support for these configuration functions to run
asynchronously (by returning a Promise that will be awaited), so that
requests could also be made to the Github API. This is benefical as it
could avoid dependence on the local Git state and the HTTP requests
are more powerful/faster.
Additionally, in order to be able to perform Github API requests
with an authenticated instance, the merge tool will pass through
a `GithubClient` instance that uses the specified `--github-token`
(or from the environment). This ensures that all API requests use
the same `GithubClient` instance and can be authenticated (mitigating
potential rate limits).
PR Close#38223
Adds support for a caretaker note label to the merge script.
Whenever a configured label is applied, the merge script will
not merge automatically, but instead prompt first in order
to ensure that the caretaker paid attention to the manual
caretaker note on the PR. This helps if a PR needs special
attention.
PR Close#37595
Integrates the merge script into the `ng-dev` CLI. The goal is that
caretakers can run the same command across repositories to merge a pull
request. The command is as followed: `yarn ng-dev pr merge <number>`.
PR Close#37138
Moves the merge script from the components repository over
to the shared dev-infra package. The merge script has been
orginally built for all Angular repositories, but we just
kept it in the components repo temporarily to test it.
Since everything went well on the components side, we now
move the script over and integrate it into the dev-infra package.
PR Close#37138