[WIP] refactor narrowing, add test, run narrow before copying

[WillForan]

also address issue #27 and could supersede pull request #28

I pulled out themeta length check into it's own function and added a test. I also moved the narrow_participants call before temporary files are copied.

The test is only checking narrowing works, not any down stream effects. And I'm worried I've likely overlooked some important considerations. Please feel free to ruthlessly reject

[Remi-Gau]

will try to review in the coming days

makes me think that this kind of thing should probably be delegated to bids-matlab which is an update and better version of spm_bids

[Remi-Gau]

but already thanks for adding tests!!!

[Remi-Gau]

Note to self:

• circle CI should run on PR
• add code linting
• use matlab github actions to run tests

[Remi-Gau]

Do you think you could rewrite this test to be used directly by matlab testing framework?

Ideally with setup and teardown functions.

https://nl.mathworks.com/help/matlab/matlab_prog/write-test-using-setup-and-teardown-functions.html

If you don't have the bandwidth, let me know and I can give it a go

[Remi-Gau]

Seems that we have a path issue when testing it:

https://app.circleci.com/pipelines/github/bids-apps/SPM/44/workflows/dd6d3670-b56f-419b-bb88-b8b6ec8f8021/jobs/220

[Remi-Gau]

Seems that we have a path issue when testing it:

https://app.circleci.com/pipelines/github/bids-apps/SPM/44/workflows/dd6d3670-b56f-419b-bb88-b8b6ec8f8021/jobs/220

that's because the new m file you have added is not copied into the container:

SPM/Dockerfile

Line 41 in 68e5b93

COPY run.sh spm_BIDS_App.m pipeline_participant.m pipeline_group.m /opt/spm${SPM_VERSION}/