[predicates] keep making `yes` predicate importable from cubicweb (closes #2790319)
The `yes` predicate was moved out in CubicWeb 3.15 but it should have
remained importable from the cubicweb.predicates module, for bw compat
reasons and also because logilab.common.registry is an implementation
detail.
"""This module compare the Schema on the file system to the one in the database"""
from cStringIO import StringIO
from cubicweb.web.schemaviewer import SchemaViewer
from logilab.common.ureports import TextWriter
import difflib
viewer = SchemaViewer()
layout_db = viewer.visit_schema(schema, display_relations=True)
layout_fs = viewer.visit_schema(fsschema, display_relations=True)
writer = TextWriter()
stream_db = StringIO()
stream_fs = StringIO()
writer.format(layout_db, stream=stream_db)
writer.format(layout_fs, stream=stream_fs)
stream_db.seek(0)
stream_fs.seek(0)
db = stream_db.getvalue().splitlines()
fs = stream_fs.getvalue().splitlines()
open('db_schema.txt', 'w').write(stream_db.getvalue())
open('fs_schema.txt', 'w').write(stream_fs.getvalue())
#for diff in difflib.ndiff(fs, db):
# print diff