How to get changed folders in pipeline when PR is merged?

Question

Hi

I'm trying to get the changed folders in bitbucket pipeline, but I'm not able to do that.

I'm using the command

git fetch origin $BITBUCKET_PR_DESTINATION_BRANCHgit diff --name-only --diff-filter=d $BITBUCKET_COMMITWhen I put hardcoded commit it is working fine ie.e

git fetch origin $BITBUCKET_PR_DESTINATION_BRANCH

git diff --name-only --diff-filter=d abwjdsefd

I'm trying to store the output in some other variable.

Script

- git diff --name-only --diff-filter=d <hard_coded_commit> > changed_1.txt- eval cat changed_1.txt- git diff --name-only --diff-filter=d $BITBUCKET_COMMIT > changed.txt- eval cat changed.txtchanged_1.txt is outputting correct values, whereas changed.txt is giving nothing.My use case is to run the pipeline for PR for changed folders and when PR is merged, I want to process those folders again with branches in pipeline.

Patrik S · Answer

You're ver welcome!

Happy to have been of some help :)

Feel free to reach out to the community if you ever need assistance in the future.

Thank you, @Shubham Mishra !

Patrik S

Shubham Mishra_m63qa1 · Answer

Hi Patrik,

Solution you suggested above worked.

Thank you for the help.

Patrik S · Answer

Hello @Shubham Mishra ,

The variable $BITBUCKET_PR_DESTINATION_BRANCH will only be available in a pull-request pipeline config.

In the branch pipeline config you have (that runs for the merge commit) this variable will be empty, so this is the reason the diff is not showing anything.

If you want to also diff the files in the branch pipeline, you will need to compare the commit that is running the pipeline (the merge commit in this case), with one of its parents. Since the merge commit has two parents (one for the feature branch and the other for the main branch), you can use the modifier ^ to identify which parent you want.

The first parent of a merge commit (^1) is from the branch you were on when you merged (usually main/master), while the second parent (^2) of a merge commit is from the branch that was merged (feature branch).

So in your case, since you are interested in the diffs introduced by the feature branch (the source branch of the pull request), you would need to use the following command in your branch pipeline config :

branches:

shubham-pipeline-test:

- step:

name: GetModifiedFilesBranchPipeline

runs-on:

- 'self.hosted'

image:

name: 'golang:1.18'

script:

- git diff --name-only --diff-filter=d HEAD^1

This will instruct git to calculate the diff between HEAD (the merge commit), and its first parent (the previous commit in the main branch). This would show all the files introduced by the feature branch into the merge commit.

Hope that helps! Should you have any questions, feel free to ask

Thank you, @Shubham Mishra !

Patrik S