SDC Property Inheritance

Drupal Single Directory Components (SDC) require replacement components (replaces:) to declare a compatible props schema, even when only Twig or CSS is overridden. In larger design systems, this often results in duplicated *.component.yml schemas.

SDC Property Inheritanceintroduces a runtime inheritance layer that allows replacement components to omit their props schema while remaining fully compatible with core SDC validation. At discovery time, the module injects the parent component’s schema into minimal override definitions, with support for partial overrides and safe merging.

All changes are applied transparently at runtime, without modifying YAML files on disk.

This module is an attempt to fix issues related to 2 core issues;

• #3527170: Allow overriding only parts of the SDC component in the theme
• #3390980: Make SDC extensible