Not equivalent - the TS compiler currently does not actually enforce the types in a JS file. See https://github.com/Microsoft/TypeScript/issues/4790#issuecommen

Not equivalent - the TS compiler currently does not actually enforce the types in a JS file. See https://github.com/Microsoft/TypeScript/issues/4790#issuecomment-220807667 https://github.com/Microsoft/TypeScript/issues/4790#issuecom... The feature of parsing JSDoc comments is currently only used for providing completion info for JS editors and for consuming exported JS functions and variables in TS files.