tsconfig.json

{
  "compilerOptions": {
    "module": "commonjs",
    "removeComments": false,
    "noLib": false,
    "lib": [
      "es2015",
      "dom"
    ],
    "target": "es2017",
    "outDir": "./build",
    "importHelpers": true,
    "esModuleInterop": true,
    "jsx": "react",
    /* Basic Options */
    "skipLibCheck": true,                     /* Skip type checking of declaration files.  */
    "sourceMap": true,                        /* Generates corresponding '.map' file. */

    /* Strict Type-Checking Options */
    "strict": true,                           /* Enable all strict type-checking options. */
    "noImplicitAny": true,                    /* Raise error on expressions and declarations with an implied 'any' type. */
    "strictNullChecks": true,                 /* Enable strict null checks. */
    "strictFunctionTypes": true,              /* Enable strict checking of function types. */
    "strictPropertyInitialization": true,     /* Enable strict checking of property initialization in classes. */
    "noImplicitThis": true,                   /* Raise error on 'this' expressions with an implied 'any' type. */
    "alwaysStrict": true,                     /* Parse in strict mode and emit "use strict" for each source file. */

    /* Additional Checks */
    "noUnusedLocals": true,                   /* Report errors on unused locals. */
    "noUnusedParameters": true,               /* Report errors on unused parameters. */
    "noImplicitReturns": true,                /* Report error when not all code paths in function return a value. */
    "noFallthroughCasesInSwitch": true,       /* Report errors for fallthrough cases in switch statement. */
    "forceConsistentCasingInFileNames": true, /* Force consistent casing in file names  */

    /* Experimental Options */
    "experimentalDecorators": true,           /* Enables experimental support for ES7 decorators. */
    "emitDecoratorMetadata": true             /* Enables experimental support for emitting type metadata for decorators. */
  },
  "include": [
    "src/**/*"
  ]
}