[Feat]: Add possibity to change the branch of the source repo

[msiebeneicher]

Describe the feature

We would like to change the branch of the source repository to sync from

Use Case

We use a version branch v1 in our source (template) repo to be able to handle breaking changes there. Now we figured out that we can only merge the main source branch in the action.

https://github.com/AndreasAugustin/actions-template-sync/blob/main/src/sync_template.sh#L275

Proposed Solution

We use a dirty workaround and "misuse" the existing git_remote_pull_params parameter : v1 --allow-unrelated-histories --squash --strategy=recursiv e -X theirs

actions-template-sync/src/sync_template.sh

Line 59 in bcb9441

GIT_REMOTE_PULL_PARAMS="${GIT_REMOTE_PULL_PARAMS:---allow-unrelated-histories --squash --strategy=recursive -X theirs}"

Better would be to add a new optional parameter like source_branch (default '') which can be used like eval "git pull ${source_repo} ${source_branch} --tags ${git_remote_pull_params}" || pull_has_issues=true

https://github.com/AndreasAugustin/actions-template-sync/blob/main/src/sync_template.sh#L275

Acknowledgements

• I may be able to implement this feature request

[AndreasAugustin]

Hi @msiebeneicher and thanks a lot for the suggestion.
Actually the idea behind the git_remote_pull_params are also to include possible branches there.
But ok out of convenience reasons I think it makes sense.

[cjlpowers]

Hi @AndreasAugustin that suggestion does not work unfortunately.

When specifying a branch in git_remote_pull_params (e.g., "my-feature-branch --strategy=recursive -X theirs"), the action appears to pull from the intended branch as expected. However, the internal check that determines whether the repository is already "up to date" only inspects the latest commit hash of the default branch (HEAD) in the source repository:

TEMPLATE_REMOTE_GIT_HASH=$(git ls-remote "${SOURCE_REPO}" HEAD | awk '{print $1}')

The script then checks if this commit exists in the target repository. If it does, it exits early with the message "repository is up to date!", even if there are changes on the actual branch specified in git_remote_pull_params.

This means that when syncing from any non-default branch, the action may incorrectly report that the repository is up to date, and skip creating a pull request—even when there are changes to sync.

I am dealing with this scenario right now. Changes made to the main branch in my source repo are showing up when syncing but the same is not true for feature branches targeted using your suggested method.

I think this could be resolved by adding a new input SOURCE_BRANCH that assumes the default branch if not provided. Then you would need to do something like this:

TEMPLATE_REMOTE_GIT_HASH=$(git ls-remote "${SOURCE_REPO}" "refs/heads/${UPSTREAM_BRANCH}" | awk '{print $1}')

and

if [[ -n "${SOURCE_BRANCH}" ]]; then
  eval "git pull ${source_repo} ${SOURCE_BRANCH} --tags ${git_remote_pull_params}" || pull_has_issues=true
else
  # fallback for legacy usage
  eval "git pull ${source_repo} --tags ${git_remote_pull_params}" || pull_has_issues=true
fi

[AndreasAugustin]

Hi @AndreasAugustin that suggestion does not work unfortunately.

When specifying a branch in git_remote_pull_params (e.g., "my-feature-branch --strategy=recursive -X theirs"), the action appears to pull from the intended branch as expected. However, the internal check that determines whether the repository is already "up to date" only inspects the latest commit hash of the default branch (HEAD) in the source repository:

TEMPLATE_REMOTE_GIT_HASH=$(git ls-remote "${SOURCE_REPO}" HEAD | awk '{print $1}')
The script then checks if this commit exists in the target repository. If it does, it exits early with the message "repository is up to date!", even if there are changes on the actual branch specified in git_remote_pull_params.

This means that when syncing from any non-default branch, the action may incorrectly report that the repository is up to date, and skip creating a pull request—even when there are changes to sync.

I am dealing with this scenario right now. Changes made to the main branch in my source repo are showing up when syncing but the same is not true for feature branches targeted using your suggested method.

I think this could be resolved by adding a new input SOURCE_BRANCH that assumes the default branch if not provided. Then you would need to do something like this:

TEMPLATE_REMOTE_GIT_HASH=$(git ls-remote "${SOURCE_REPO}" "refs/heads/${UPSTREAM_BRANCH}" | awk '{print $1}')
and

if [[ -n "${SOURCE_BRANCH}" ]]; then
eval "git pull ${source_repo} ${SOURCE_BRANCH} --tags ${git_remote_pull_params}" || pull_has_issues=true
else

fallback for legacy usage

eval "git pull ${source_repo} --tags ${git_remote_pull_params}" || pull_has_issues=true
fi

Hi @cjlpowers nice find. Will have a look into it ASAP.