Allow more complex attribute replacement behaviors

[amanda-mitchell]

🚀 Feature Proposal

It would be super cool if the --replace-attr-values feature allowed substitution of javascript expressions instead of just strings, for example

Motivation

Our application contains a number of assets that can be rethemed by swapping out a color palette. Having a way to dynamically replace the colors in the original image with values from a palette would enable us to simplify our designers' workflows.

Example

Perhaps if the replacement value is surrounded by curly braces, it could be treated as an expression instead of a string?

--replace-attr-values "#063855={props.primaryColor}"

While this would be a breaking change, it seems unlikely (to me, anyway) that there would be valid uses of this syntax already in the wild.

Pitch

It seems like a relatively natural extension of the replacement feature.

[Venablena]

+1 This is the exact same feature I'm after right now.