Write a BIDS-friendly .gitattributes at babs init

babs/bootstrap.py

@@ -21,6 +21,21 @@
     validate_processing_level,
 )
 
+# Analysis-dataset `.gitattributes`: annex a file if it is binary
+# (`mimeencoding=binary`, which needs git-annex's MagicMime build flag) or
+# larger than 40kb; the explicit lines force listed files into git regardless.
+BIDS_GITATTRIBUTES = """\
+* annex.backend=MD5E
+* annex.largefiles=((mimeencoding=binary)or(largerthan=40kb))
+**/.git* annex.largefiles=nothing
+.babs/** annex.largefiles=nothing
+dataset_description.json annex.largefiles=nothing
+.bidsignore annex.largefiles=nothing
+README* annex.largefiles=nothing
+CHANGES annex.largefiles=nothing
+LICENSE annex.largefiles=nothing
+"""
+
 
 class BABSBootstrap(BABS):
     """A BABS subclass that implements the bootstrap process."""
@@ -121,6 +136,15 @@ def babs_bootstrap(
         if self.shared_group is not None:
             create_kwargs['initopts'] = ['--shared=group']
         self._analysis_datalad_handle = dlapi.create(self.analysis_path, **create_kwargs)
+
+        # Overwrite the create-time `.gitattributes` before any content is
+        # saved, so the annex policy applies to every file (see
+        # BIDS_GITATTRIBUTES):
+        gitattributes_path = op.join(self.analysis_path, '.gitattributes')
+        with open(gitattributes_path, 'w') as f:
+            f.write(BIDS_GITATTRIBUTES)
+        self.datalad_save(path='.gitattributes', message='Use a BIDS-friendly .gitattributes')
+
         self.input_datasets.update_abs_paths(Path(self.analysis_path))
         self.input_datasets.set_inclusion_dataframe(initial_inclusion_df, processing_level)
 

tests/test_base.py

@@ -17,10 +17,16 @@
 
 from babs import BABSCheckSetup
 from babs.base import BABS, CONFIG_SECTIONS
-from babs.bootstrap import BABSBootstrap
+from babs.bootstrap import BIDS_GITATTRIBUTES, BABSBootstrap
 from babs.utils import read_yaml
 
 
+def test_bootstrap_writes_bids_gitattributes(babs_project_sessionlevel):
+    """`babs init` installs the BIDS-friendly `.gitattributes` in `analysis/`."""
+    gitattributes = Path(babs_project_sessionlevel) / 'analysis' / '.gitattributes'
+    assert gitattributes.read_text() == BIDS_GITATTRIBUTES
+
+
 def test_missing_config_parts(babs_project_sessionlevel):
     """Test that missing config parts raise an error."""