Cannot find name 'describe'. Do you need to install type definitions for a test runner? Try `npm i --save-dev @types/jest` or `npm i --save-dev @types/mocha`.

Cannot find name 'it'. Do you need to install type definitions for a test runner? Try `npm i --save-dev @types/jest` or `npm i --save-dev @types/mocha`.

Cannot find name 'jest'.

Cannot find name 'expect'.

Cannot find name 'it'. Do you need to install type definitions for a test runner? Try `npm i --save-dev @types/jest` or `npm i --save-dev @types/mocha`.

Cannot find name 'jest'.

Cannot find name 'expect'.

Cannot find name 'it'. Do you need to install type definitions for a test runner? Try `npm i --save-dev @types/jest` or `npm i --save-dev @types/mocha`.

Cannot find name 'jest'.

Cannot find name 'expect'.