Adding more dedicated exceptions

[ThomasLandauer]

Type of pull request

• Bug fix (involves code and configuration changes)
• New feature (involves code and configuration changes)
• Documentation update
• Something else

About

Adding 2 dedicated exceptions, following the path of #433

2 remarks:

• Please create a file CONTRIBUTING.md, according to https://docs.github.com/en/communities/setting-up-your-project-for-healthy-contributions/setting-guidelines-for-repository-contributors and include all information from the checklist (here below)
• I don't know how to run the unit tests, nor cs-fixer.

Checklist for code / configuration changes

In case you changed the code/configuration, please read each of the following checkboxes as they contain valuable information:

• Please run PHP-CS-Fixer before committing, to confirm with our coding styles. See https://github.com/smalot/pdfparser/blob/master/.php-cs-fixer.php for more information about our coding styles.

[k00ni]

👍 I like your idea of dedicated exceptions. While we are at it, can you think of other exception types?

The remarks are also important, but I would like to discuss these in a separate issue/pull request. A dedicated CONTRIBUTING.md file seems to be a good idea. Would you mind suggesting one in a separate PR?

[ThomasLandauer]

While we are at it, can you think of other exception types?

Fulltext search for \Exception yields some hits. Do you want me to go through them and create exceptions? (But I'd just take the current exception message and create a class from it - I won't research the context) Or just leave it up to others who have a real need (and know why/when it occurs)?

A dedicated CONTRIBUTING.md file seems to be a good idea. Would you mind suggesting one in a separate PR?_

I'm a beginner with git, so I'm probably the wrong person. As a starting point, you can copy over what you currently have. I was annoyed yesterday to find your checklist only after I had finished my PR - so the idea is just to tell people upfront :-)

[k00ni]

Sorry for my delayed response. To move this forward, the code should be inspected to find further instances of these exceptions. Only replacing a few instances without covering the whole code base might lead to false implications by developers when using the API.

@ThomasLandauer would you mind searching for further instances where using these new exceptions might be a good idea?

[k00ni]

Closing this for now due to inactivity by the author. Feel free to comment when you want to continue working on it.

[ThomasLandauer]

Sorry, I didn't know what to do exactly. Do you want me to just replace all occurrences of "my" 2 exceptions? Or create a new exception for every other \Exception in the code base too?

[k00ni]

Please go through the code to find further instances of these exceptions and replace them with the new ones when appropriate.

[ThomasLandauer]

There are ~20 places where exceptions are thrown, but these 2 new appear only once. So IMO you can merge this.

[k00ni]

Thanks for checking.

Here is a brief summary of my latest changes:

• added a short comment for each new exception
• added another exception (NotImplementedException)
• fixed coding style issues (ran dev-tools/vendor/bin/php-cs-fixer fix locally)