tsconfig.json

{
  "compilerOptions": {
    // https://www.typescriptlang.org/docs/handbook/compiler-options.html
    "outDir": "dist",
    "incremental": true,

    "target": "es2017",
    "lib": ["es2017"],
    "module": "commonjs",

    "esModuleInterop": true, // release notes 2.7: "We highly recommend applying it both to new and existing projects"
    "moduleResolution": "node",
    "sourceMap": true,
    "experimentalDecorators": true,
    "resolveJsonModule": true,
    "removeComments": true,
    "isolatedModules": true,
    // Meant to cause it to treat all files as modules, to address this:
    // https://stackoverflow.com/q/40900791/cannot-redeclare-block-scoped-variable-in-unrelated-files
    // But initial observation is that it doesn't seem to have any impact (I still need to use work-around).
    
    // "strict" enables all strict type checking options, including noImplicitAny, noImplicitThis, alwaysStrict, & strict*
    "strict": true, 
    // "noImplicitAny": false, // Had to do this to augment global namespace // https://stackoverflow.com/a/56984941/150016
    "noImplicitUseStrict": true, // Do not emit "use strict" directives in module output (it was inserting it in json files).
    "alwaysStrict": false, // noImplicitUseStrict requires that "alwaysStrict" be left off, but 'strict: true' turned it on. 

    "noImplicitReturns": true,
    // Can't make these just warnings - so turn them off and let eslint catch them.
    "noUnusedLocals": false,
    "noUnusedParameters": false
  },
  "compileOnSave": true,
  "include": [
    "src"
  ],
  // Do I need both include & exclude?
  "exclude": [
    "node_modules",
    "dist" // it automatically excludes the "outDir", unless "exclude" is specified.
  ]  
}