ts-r
  • Sound mode S-12, pre-alpha
  • Design record 0007, Accepted

TSR1204

Global augmentation in a sound file changes types for the whole program without a check. Move it to a '.d.ts' file.

'declare global' or a global merge from a script file in a sound file changes types program-wide. Move it to a .d.ts file.

Rule S-12: No suppression comments, overload implementations or global augmentation (level: sound). Reported by ts-r-check and ts-r-lsp in files that opt in to sound mode. See Sound mode.

What it means

declare global { ... } and global declarations merged from a script file (such as interface Array<T> { ... } at the top level of a non-module file) change types for the whole program without a check. In a sound file they are reported at global, or at the merged declaration's name.

Example

Spec case from design record 0007 (checked by the record's case harness, not by this site's build)
// Global augmentation changes types for the whole program.
declare global { // @expect TSR1204
  interface Window {
    tsrFixtureState?: string;
  }
}
export {};

How to fix

  • Move the declare global block into a project .d.ts file.

Sound mode is defined in design record 0007 (accepted 2026-10-15).