Test Multiple Typescript Versions Using TSC

3.9|package.json

{
  "name": "Tests against TS v3.9",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "dependencies": {
    "typescript": "^3.9.2"
  }
}

3.9|test.ts

export const a: `${string}world` = "hello world";

4.1|package.json

{
  "name": "Tests against TS v4.1",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "dependencies": {
    "typescript": "^4.1.2"
  }
}

4.1|test.ts

export const a: `${string}world` = "hello world";

package.json

{
  "name": "root",
  "version": "1.0.0",
  "main": "index.js",
  "license": "MIT",
  "scripts": {
    "test:types": "cd 4.1 && yarn run tsc -b ../tsconfig.json && cd ../3.9 && yarn run tsc -b ../tsconfig.json"
  }
}