Create new notice for missing shapes.txt file

[owades]

Describe the problem

Per the California Minimum General Transit Feed Specification (GTFS) Guidelines, the file shapes.txt is required for all GTFS schedule feeds. We don't yet have a validation rule that checks for the file's presence.

Describe the new validation rule

I can think of two options:

1. Go through the process of making shapes.txt a "required file", so it will be caught with the missing_required_file error
2. Create a new warning called missing_shapes_file, which appears whenever the file is not present for a given feed.

Sample GTFS datasets

No response

Severity

Warning

Additional context

No response

[isabelle-dr]

Hello @owades, thanks for opening this issue!

This validator "only" validates according to the official specification, and GTFS Best Practices. We would like to offer users the possibility to set up their own criteria easily, so they can evaluate feeds according to what matters to them, and they can share their criteria with others in a more efficient way. There is ongoing work to support this, and the discussion is happening in issue #1067. Cal-ITP's GTFS Guidelines are actually used as a use case!
@asvechnikov2 at Google proposed a modification of the validator to support this, feel free to have a look at it, it is linked below in the same issue.

So one option that is not listed here will be to add this check as part of future Cal-ITP's set of rules when this functionality will be released. 😊

About the two options you proposed:

Go through the process of making shapes.txt a "required file", so it will be caught with the missing_required_file error

Making this file Required in the specification would break backward compatibility (feeds previously valid becoming invalid), which is one of the core principles in GTFS.

Create a new warning called missing_shapes_file, which appears whenever the file is not present for a given feed.

If this was added to the Best Practices first, we could add this check as part of the canonical set of rules. Here is a link to the amendment process if you'd like to try that route.

[isabelle-dr]

Labeling as blocked, this rule can be added if either:

• we close issue Proposal: Modify Validator to allow for custom validation #1067
• this is added to the Best practices

[owades]

Thanks for the helpful explanation, @isabelle-dr! I believe we will eventually try to take the amendment route.