Is adding a d.ts type declaration file and a new "types" property in the package.json of a JavaScript npm package considered a breaking change? Would it require a major version bump according to SemVer?
This situation could go either way. It doesn't impact the JavaScript code and doesn't break any APIs. However, there is a chance of conflicts with custom d.ts types if someone is using the library in a TypeScript project, leading to errors like "Duplicate Identifier."