🐞 Bug Report: Optional metadata properties aren't handled as such

[johnbillion]

Detailed Description

Various DID metadata properties are optional but lead to the FAIR plugin triggering PHP warnings when they're not present:

• sections
• filename (not actually part of the FAIR spec)
• release.requires
• release.suggests

Expected Behavior

Metadata properties that are optional should be handled as such.

Current Behavior

PHP warnings are triggered in the following locations:

• fair-plugin/inc/packages/namespace.php

  Line 177 in c47e9f2

  $body->sections = (array) $body->sections;

• fair-plugin/inc/packages/namespace.php

  Line 379 in c47e9f2

  foreach ( $release->requires as $pkg => $vers ) {

• fair-plugin/inc/packages/namespace.php

  Line 388 in c47e9f2

  foreach ( $release->suggests as $pkg => $vers ) {

• fair-plugin/inc/packages/namespace.php

  Line 570 in c47e9f2

  list( $slug, $file ) = explode( '/', $filename, 2 );

Steps to Reproduce

1. Install a plugin which uses a FAIR metadata document that only contains the minimal fields that are required by the FAIR protocol spec.
   • If you're testing with existing plugin or data you'll need to flush transients
2. Trigger update checks.
3. Observe PHP errors from the FAIR plugin.

[afragen]

fairpm/fair-protocol#37 adds filename to spec

I think we are running into the issue of what is a requirement for the general spec and what is a requirement for WordPress. I believe the above are all above are WP-extensions and are required in that context.

[norcross]

@johnbillion this was also reported in #367 and fixed in #372