[Question] How can I implement a redirect editor deduplicated by fromUrl?

Background

I wanted to enable configuring URL redirects, e.g.

• /very-long-path -> /vlp
• /deprecated-page -> /

I was able to create a configuration page by either collections or a singleton with array of object(fromUrl, toUrl) field.

Problem

However, I was not able to find a way to deduplicate by fromUrl field. E.g.

• /very-long-path -> /vlp
• /deprecated-page -> /
• /very-long-path -> / (Adding this does not make sense, as it conflicts with the first config. But it is allowed from the UI)

My question is: How do I deduplicate my collections or array items with a specific field value?
When there are more entries it's hard to find duplicates so it's better to have a programatic way.
My current workaround is to run a ci check for duplications, but it's better if we know that when we are editing it.

Possible solutions

• Validation function across array items
• A fields.map type that allows user enter key and value, and key must be unique.

Start by reviewing the existing collection, singleton, array, and fields.map configuration APIs referenced in the issue. Determine whether validation can inspect sibling items and enforce unique fromUrl values, or whether a keyed field type is needed. Done means identifying a supported approach or clearly scoping the required editor and validation change.