feat: uniqueRaw and unique

[Xstoudi]

🔗 Linked issue

#995

❓ Type of change

• 🐞 Bug fix (a non-breaking change that fixes an issue)
• 👌 Enhancement (improving an existing functionality like performance)
• ✨ New feature (a non-breaking change that adds functionality)
• ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

Current unique rule becomes uniqueRaw as proposed by @thetutlage on #995 and we add a new unique allowing a simpler and more expressive API inspired from Adonis v5.

Feel free to comment the implem, I'm not fully familiar with Adonis codebase. I couldn't found the doc about future old unique rule, can you show me where it's mentionned in the doc so I can update the doc?

📝 Checklist

• I have linked an issue or discussion.
• I have updated the documentation accordingly.

[thetutlage]

Hey, both unique and uniqueRaw could be the same overload function. Because, right now this PR will lead to a breaking change, and that's something we should avoid.

Also let's add some tests for the new implementation.

Feel free to comment the implem, I'm not fully familiar with Adonis codebase. I couldn't found the doc about future old unique rule, can you show me where it's mentionned in the doc so I can update the doc?

Haha, seems like it never got documented. So we will have to document it from scratch.

[Xstoudi]

It use overload now.

I'm not sure how to get started to write test for a binding and for as much as I looked, I cannot use previous test to get inspiration because they do not exist (or I can't find it).

Where do you think we should document it? On the Lucid doc with a Rules contributed by Lucid like this:https://docs.adonisjs.com/guides/validation#rules-contributed-by-adonisjs ?