tsconfig.json

{
  "compilerOptions": {
    // "allowJs": true, // not enabling this for now, not sure I will need imports of .js files
    "target": "es6",
    "lib": ["ES2017", "dom"],
    "module": "es6", // https://www.typescriptlang.org/tsconfig/#module
    "moduleResolution": "bundler", // not sure this is a wise choice, since I am not targeting a bundler currently, but the docs are confusing https://www.typescriptlang.org/docs/handbook/modules/theory.html#module-resolution
    "isolatedModules": true, // warn if you write certain code that can’t be correctly interpreted by a single-file transpilation process https://www.typescriptlang.org/tsconfig/#isolatedModules
    "esModuleInterop": true, // not sure I need this https://www.typescriptlang.org/tsconfig/#esModuleInterop
    "allowSyntheticDefaultImports": true, // https://www.typescriptlang.org/tsconfig/#allowSyntheticDefaultImports
    "forceConsistentCasingInFileNames": true, // imported files are forced to have same casing as file on disk
    "noFallthroughCasesInSwitch": true,
    "noImplicitOverride": true,
    "noImplicitReturns": true,
    "noImplicitThis": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "resolveJsonModule": true, // allow import of json modules
    "sourceMap": true,
    "strict": true,
    "jsx": "react-jsx",
    "outDir": "extension", // consumed by webpack
    "rootDir": "src" // consumed by webpack
  },
  "include": ["src/**/*", "typings"]
}