[BUG] Document and check for RoadwayNetwork.shape_foreign_key

[lmz]

Describe the bug

I was trying to use a script that errored out when applying a project card that added new roadway links. On digging, I found it was because the RoadwayNetwork.shape_foreign_key was being used to access columns in both the shapes_df and links_df:

network_wrangler/network_wrangler/roadwaynetwork.py

Lines 1727 to 1732 in 6ed2240

	self.links_df[self.shape_foreign_key] = self.links_df.apply(
	lambda x: create_unique_shape_id(x["geometry"])
	if x["new_link"] == 1
	else x[self.shape_foreign_key],
	axis=1,
	)

I think this is ok but it should be documented clearly and also fail earlier by checking that links_df has the column, in the same way that the check is done for shapes_df:

network_wrangler/network_wrangler/roadwaynetwork.py

Lines 507 to 512 in 6ed2240

	if self.shape_foreign_key not in self.shapes_df.columns:
	valid = False
	msg = "Network doesn't contain unique shape id: {}".format(
	self.shape_foreign_key
	)
	WranglerLogger.error(msg)

Status

• Defined
• Planned
• Implemented
• Tested

To Reproduce

Steps to reproduce the behavior:

1. Create a network with a shape_foreign_key that exists in shapes_df but not links_df
2. Apply a project card that creates roadway links

Failing tests

• No applicable test failed, need to create.
• [ ]

Triggering line of code

Thoughts on resolution

Full stack trace

Environment

Operating system:
Context (conda, jupyter, etc):
Environment (e.g. output from conda list):

[e-lo]

Resolved in v1.0 release candidate by being much more rigorous about data models for networks including checking for FKs