I could have split this into several commits:
* DRY direct linking to images.
* Check S3 config before direct linking.
* Just check if service is public instead of relying on name.
Developers may copy a staging or production database or experiment with
S3 storage. But when the S3 config is missing then calling `service`
raises an ArgumentError due to a missing name.
Now we only try to call `service` if the S3 config is present.
Defining an alternate s3 configuration set to `public: true` means we can use it selectively. It sets the objects to `acl: "public-read"` by default (read-only) and means any image tags for those assets can use direct public links in the src attribute (without hitting the ActiveStorage::Representation endpoint). The default non-public service will still be used by default for any other files on instances using s3.
I discovered that twitter doesn't have 'www' in the url anymore, no '@' symbol and interestingly no trailing slash. I added back the '@' just so we can test that still.
Using a regex group we can cater for optional www in a single regex.
We introduced a list of formats we support and forgot to add webp. Now I
added that as allowed format again and modified the error message.
I removed the first sentence from the error message because it's very
similar to the default error which is shown as well.
Strips '+' and ' ' characters from the phone number for the generated
link, but doesn't guarantee the link is valid because the number
registered isn't validated for now.
Australian production had one JPG image which was not recognised as
such. The `content_type` was missing and trying to generate a URL for a
variant raised an error and crashed the page.
Testing for `variable?` includes testing for `attached?` and is more
defensive.
We configured Paperclip to convert images to JPG in some cases but I
omitted that here because we don't need it. If an image is better
represented as PNG or another format then the user should be able to
choose that.
Some specs were also testing the generated URL but the Active Storage
URL doesn't contain a style name anymore and it's not helpful to test
the URL.
We do this for all models in the code base. There's one special case,
the ConentConfiguration which is not a model and we can't use the same
approach there. We will have to deal with that separately later.
