#tsconfig

Every app in a micro-frontend platform should be held to the same TypeScript rules, and changing a rule should be a one-line edit rather than a change in a dozen files. This feature makes every app extend one shared set of presets.

#What you get

Each app gets a small tsconfig.json that extends a preset from @mfeflow/tsconfig, and a typecheck script. The presets turn on the strict checks that catch real bugs, such as unchecked array access and optional properties that are really undefined.

#It is already there

You do not add this one. It is part of every project, so mfeflow init applies it and it is not offered as a choice. Features such as lint-oxlint and http list it as a requirement.

What it wrote:

tsconfig.json               # project root, for scripts and end-to-end tests
apps/
├── shell/tsconfig.json     # extends a preset
└── <remote>/tsconfig.json  # extends a preset

Dev dependencies and scripts:

@mfeflow/tsconfig   # the presets
typescript 7.0.2    # the compiler
typecheck           # a script in each app and one at the root

#Use it

An app's file extends the preset and lists what to check.

{
  "extends": "@mfeflow/tsconfig/react-app.json",
  "compilerOptions": { "types": ["node"] },
  "include": ["src", "rsbuild.config.ts", "env.ts", "vitest.config.ts"]
}

The root file uses the Node preset.

{
  "extends": "@mfeflow/tsconfig/node.json",
  "include": ["*.ts", "scripts", "e2e"]
}

Run the checks from the root. Each app runs tsc --noEmit, and the root script fans out through Turborepo.

pnpm typecheck

#Configure it

There are no install options. You choose a preset, and you override single compiler options in the app's own file.

Generated apps use react-app.json and the root uses node.json. The library preset is there for packages you publish.

#How it works

The base preset targets ES2022 with bundler module resolution, and turns on these checks beyond strict:

"strict": true,
"noUncheckedIndexedAccess": true,
"exactOptionalPropertyTypes": true,
"noImplicitOverride": true,
"noFallthroughCasesInSwitch": true,
"verbatimModuleSyntax": true,
"isolatedModules": true

Rsbuild does the building, so TypeScript only checks, which is why the app presets are noEmit. The package needs TypeScript 7 or newer as a peer dependency.

#Gotchas

Add a new file or folder to include in the app's tsconfig.json, or the check will not see it.

#Reference

• lint-oxlint, which reads the same TypeScript setup
• Project structure
• Upgrading
• feature.json reference