Resolves #150

[netbrothers-tr]

This PR introduces a non-intrusive handling of issue #150 which states that a PHP warning (Undefined array key) is issued during parsing in some cases (presumably when parsing non-standard UN/EDIFACT data).

[netbrothers-tr]

Unit tests did pass locally but I noticed that code style fixing (vendor/bin/ecs) did not (and is not checked in CI). Should this be addressed, @sabas?

[sabas]

Yes we should edit some configuration? I ran it manually some time ago..

[netbrothers-tr]

@sabas, I see two separate issues here:

1. The code-style issue: We could add easy-coding-standard (ecs) as a step in the CI workflow (.github/workflows/ci.yml). This should be an easy fix and if you want, I will create another issue for this and provide a PR.

2. But the reason the CI pipeline fails is a different one, i.e. an authentication error. Sometimes re-running the build fixes the issue. Would you mind triggering another run? If it still fails, there are IMHO two things to consider:

• 1. I could imagine this has either something to do with the repositories configuration in the composer.json¹, which seems to be unnecessary (?!?) or
• 2. the Composer Action needs an access token, but this would be pretty unlikely because we deal with publicly available packages, altogether.

¹ See this comment for reference.

[sabas]

I edited ci.yml to solve 2. For 1 it would only report if there's need to be run?

      - name: Run Easy Coding Standard
        run: vendor/bin/ecs check --config ecs.php --no-progress