Summary & Key Takeaways ​

• Solid 1.x attribute forms like on:, attr:, and classList now trigger compile errors on native elements.
• The compiler provides specific 2.0 replacements for deprecated attribute forms.
• Dev builds now warn about UNCOMMITTED_INPUT_OVERWRITTEN when DOM property bindings overwrite user edits.
• These checks run at compile time and add no runtime code.

Our Commentary ​

Breaking changes are never fun, but enforcing the new 2.0 attribute forms at compile time is the right move. It's a clear signal for migration. The UNCOMMITTED_INPUT_OVERWRITTEN warning is also a fantastic addition for developer experience; I've seen that bug sneak into apps more times than I care to admit.