tsconfig.base.json

{
  "compilerOptions": {
    // https://www.typescriptlang.org/tsconfig#baseUrl
    "baseUrl": ".",

    // All new TypeScript projects should use "esModuleInterop": true.
    // https://esbuild.github.io/content-types/#es-module-interop
    // https://www.typescriptlang.org/tsconfig#esModuleInterop
    "esModuleInterop": true,

    // https://www.typescriptlang.org/tsconfig#forceConsistentCasingInFileNames
    "forceConsistentCasingInFileNames": true,

    // Setting "importHelpers" to true would mean that a consumer of a library
    // of this monorepo would need to declare tslib as a dependency. Don't do it!
    // https://www.typescriptlang.org/tsconfig#importHelpers
    "importHelpers": false,

    // This is not important for this project, but it speeds up compilation
    // times, so I want to remember it for larger projects.
    // https://www.typescriptlang.org/tsconfig#incremental
    "incremental": true,

    // This project uses esbuild to bundle its applications. esbuild compiles
    // the files independently, so we must set "isolatedModules": true.
    // https://esbuild.github.io/content-types/#isolated-modules
    // https://www.typescriptlang.org/tsconfig#isolatedModules
    "isolatedModules": true,

    // Leave "lib" empty here, and define it in the tsconfig of each package, so
    // it's more explicit.
    // https://www.typescriptlang.org/tsconfig#lib
    "lib": [],

    // All of the libraries of this monorepo are compiled for ESM only (no CJS).
    // https://www.typescriptlang.org/tsconfig#module
    // https://www.typescriptlang.org/docs/handbook/module-resolution.html
    "module": "es2020",

    // TypeScript 4.5 (released on 16th November, 2021) can use "nodenext" to
    // support ECMAScript Modules (ESM).
    // https://devblogs.microsoft.com/typescript/announcing-typescript-4-5-beta/
    // https://www.typescriptlang.org/tsconfig#moduleResolution
    // https://www.typescriptlang.org/docs/handbook/module-resolution.html
    "moduleResolution": "node",
    // "moduleResolution": "nodenext",

    // https://www.typescriptlang.org/tsconfig#noImplicitAny
    "noImplicitAny": true,

    // https://www.typescriptlang.org/tsconfig#noUnusedLocals
    "noUnusedLocals": true,

    // https://www.typescriptlang.org/tsconfig#noUnusedParameters
    "noUnusedParameters": true,

    // paths are resolved relative to baseUrl
    // I am not sure if I really need these path mappings. I do need the path
    // mapping in my Jest config, but these ones?
    // https://www.typescriptlang.org/tsconfig/#paths
    "paths": {
      "@jackdbd/*": [
        "../packages/*/lib/index.d.ts",
        "../packages/*/lib/index.js"
      ]
    },

    // As far as I understand, preserveConstEnums has no effect for non-const
    // enums and should not affect the bundle size, but it must be set to true
    // when isolatedModules is set to true.
    // https://stackoverflow.com/questions/28818849/how-do-the-different-enum-variants-work-in-typescript
    // https://www.typescriptlang.org/tsconfig#preserveConstEnums
    // https://ncjamieson.com/dont-export-const-enums/
    "preserveConstEnums": true,

    // it would be safer to set skipLibCheck to false, but it's kind of slow.
    // Maybe enable it from time to time to type check dependencies.
    // https://www.typescriptlang.org/tsconfig#skipLibCheck
    "skipLibCheck": true,

    // In most cases I want to generate source maps.
    // https://m.signalvnoise.com/paying-tribute-to-the-web-with-view-source/
    "sourceMap": true,

    // strict mode sets many strict compiler options to true in one go.
    // https://www.typescriptlang.org/tsconfig#strict
    "strict": true,

    // https://www.typescriptlang.org/tsconfig#strictNullChecks
    "strictNullChecks": true,

    // The libraries of this monorepo target Node.js
    // You may “mix and match” target and lib settings as desired, but you could
    // just set target for convenience.
    // https://www.typescriptlang.org/tsconfig#target
    // https://node.green/
    "target": "es2020",

    // https://www.typescriptlang.org/tsconfig#typeRoots
    "typeRoots": ["../node_modules/@types", "../custom-types"],

    "verbatimModuleSyntax": true
  },

  "exclude": [
    // monorepo root node_modules. Those dependencies that are hoisted by npm
    // workspaces end up here.
    "../node_modules",
    // node_modules of each package. Those dependencies that npm cannot hoist
    // end up here. This happens because different packages require a different
    // version of the same dependency.
    "../packages/*/node_modules"
  ]
}