tsconfig.json

// https://github.com/vercel/next.js/blob/canary/packages/create-next-app/templates/app/ts/tsconfig.json
{
  "compilerOptions": {
    // next
    "target": "es5",
    "lib": ["dom", "dom.iterable", "esnext"],
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true,
    "noEmit": true,
    "esModuleInterop": true,
    "module": "esnext",
    "moduleResolution": "node",
    "resolveJsonModule": true,
    "isolatedModules": true,
    "jsx": "preserve",
    "incremental": true,
    // strict
    "strict": true,
    "verbatimModuleSyntax": true,
    // strictest
    "allowUnusedLabels": false,
    "allowUnreachableCode": false,
    "exactOptionalPropertyTypes": true,
    "noFallthroughCasesInSwitch": true,
    "noImplicitOverride": true,
    "noImplicitReturns": true,
    "noUncheckedIndexedAccess": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    // checkJs
    "allowJs": true,
    "checkJs": true,
    // custom
    "paths": {
      "@/*": ["./src/*"]
    },
    "plugins": [
      {
        "name": "next"
      },
      {
        "name": "typescript-plugin-css-modules",
        "options": {
          "classnameTransform": "camelCase"
        }
      }
    ]
  },
  "include": ["next-env.d.ts", "**/*.ts", "**/*.tsx", ".next/types/**/*.ts"],
  "exclude": ["node_modules"]
}