what is tsconfig.spec.json code example

Example 1: tsconfig.json not generated

$ tsc --init

Example 2: tsconfig configuration

{
  "compilerOptions": {
    "target": "ES2015",
    "module": "commonjs",
    "lib": [ "ES2015", "dom" ],
    "sourceMap": true,
    "outDir": "./script", 
    "strict": true, 
    "strictNullChecks": true, 
    "strictFunctionTypes": true, 
    "noImplicitThis": true, 
    "alwaysStrict": true, 
    "noImplicitReturns": true, 
    "noFallthroughCasesInSwitch": true,
    "esModuleInterop": true,
    "experimentalDecorators": true, 
  }
}