Add support for box-shadow and filter properties

[wojtekmaj]

Closes #195

React Native supports box-shadow and filter properties natively since version 0.76. This means that every version of React Native that is stil supported can benefit from box-shadow and filter properties.

This may be considered a breaking change, since this drops support for React Native 0.75 and older - at the benefit of supporting newer versions, on which styling is currently broken.

How I tested it?

• Added tests
• Compiled the code myself and replaced dependency in a real project (see below)

const Box = styled.View`
  width: 50px;
  height: 50px;
  background-color: black;
  box-shadow: 5px 5px 5px red, -5px -5px 5px green;
  filter: opacity(0.5);
`;

<Box />

Before:

After:

[Copilot]

Pull request overview

This PR updates the CSS-to-React-Native transform behavior to align with newer React Native (>= 0.76) support for box-shadow and filter by passing them through as native style props instead of transforming box-shadow into legacy shadow* fields.

Changes:

• Removes the boxShadow shorthand transform so box-shadow is treated as a raw, camelCased prop (boxShadow).
• Adds/updates tests to assert pass-through behavior for filter and box-shadow, including multiple values.
• Updates README guidance to reflect the new pass-through behavior and RN version dependency.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/transforms/index.js	Stops registering the boxShadow transform so box-shadow is no longer expanded into shadow* props.
src/transforms/boxShadow.js	Deletes the legacy box-shadow parsing/expansion implementation.
src/__tests__/units.js	Updates the units test expectation for box-shadow to match pass-through behavior.
src/__tests__/index.js	Adds test coverage for raw pass-through of filter and box-shadow (including multiple functions/values).
src/__tests__/boxShadow.js	Removes tests that validated the old box-shadow -> shadow* expansion behavior.
README.md	Updates documentation to describe pass-through behavior for box-shadow and filter.
.DS_Store	Adds an unintended macOS metadata file to the repo.

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[jacobp100]

I think this is fine to get in, but would be a breaking change. If you bump the version number, we can merge. Then we'd need a separate PR in styled-components to bump the dependency version

[wojtekmaj]

@jacobp100 Done! I wasn't sure how you wanted to manage this, hence I left that part out before.

[jacobp100]

One conflict

@mxstbr Are you still doing releases - or know who would do a release?

[wojtekmaj]

Zero conflicts 😎