nodemon --exec ts-node versus precompiled JavaScript: a restart decision guide

The problem: restart TypeScript without a manual build step

You are editing src/index.ts and want the running Node process to restart on save. nodemon can watch files and restart the process, but TypeScript cannot be executed by Node directly. You must either run the TypeScript through an interpreter such as ts-node, or compile it to JavaScript first and point nodemon at the emitted output. Each path changes restart speed, type safety, and the risk of restart loops.

Useful takeaway: choose nodemon --exec ts-node for local development when immediate feedback matters. Choose precompiled JavaScript when you want full tsc type-checking before execution or need the running code to match the production build exactly.

Constraints to decide against

• Team members should not have to remember different CLI flags.
• Bulk file saves should not trigger a restart storm.
• Generated output directories must not be watched, or nodemon can restart repeatedly.
• Local tooling should not replace a full type-check in CI.

Supported options compared

Option	Typical command	Type checking	Build step	Best suited for
nodemon --exec ts-node	nodemon --exec ts-node src/index.ts	Limited, performed by ts-node	None	Fast local development feedback
tsc then nodemon on .js	tsc, then nodemon dist/index.js	Full, performed by tsc before emit	Required	Production-like execution path
Plain nodemon on .js	nodemon dist/index.js	None	Required, handled externally	JavaScript-only projects

Trade-offs

nodemon --exec ts-node

The --exec flag tells nodemon to launch the target script through an interpreter instead of Node directly. With ts-node, TypeScript is transpiled and executed in one step. Edits to .ts files trigger a restart without a separate tsc run. The downside is that ts-node performs limited type checking; some type errors reach runtime instead of failing at compile time.

Precompiled JavaScript

Running tsc first catches type errors before nodemon ever starts the process. The emitted JavaScript runs under plain Node, which matches production more closely. The cost is an extra build step and slower feedback after every edit unless you also run tsc --watch in parallel.

Restart delay

If you save many files at once, nodemon may restart repeatedly. The --delay option adds a quiet period before restarting. A value of 500 to 1000 milliseconds is a practical starting point.

Implementation: shared nodemon.json

Create nodemon.json in the project root so every team member gets the same watch and restart behavior without repeating flags.

{
  "exec": "ts-node",
  "script": "src/index.ts",
  "watch": ["src"],
  "ignore": ["dist", "node_modules", "*.test.ts"],
  "ext": "ts,json",
  "delay": 500
}

Where to run: terminal at the project root.

Permissions: no elevated permissions required; the user must be able to read the project files and execute nodemon.

Expected checks:

• nodemon --version prints a version number, confirming the CLI is installed.
• Running nodemon starts ts-node and loads src/index.ts.
• Saving a change to src/index.ts produces a restart message without a manual tsc command.

Risk: ts-node does not replace tsc --noEmit. Type errors may appear at runtime. Watching the dist directory can create a restart loop because compiled output changes trigger nodemon, which triggers more compilation. The ignore array above prevents that.

Validation

1. Run nodemon --version to confirm the CLI responds.
2. Start nodemon --exec ts-node src/index.ts, or simply nodemon if nodemon.json is present.
3. Modify a source file in src and save.
4. Confirm nodemon logs a restart and the process continues without manual rebuild.
5. Run npx tsc --noEmit separately to verify type errors are caught outside the nodemon loop.

Limitations

This guide covers local development restarts. It does not cover production process management, cluster mode, or debugging configuration. ts-node behavior may vary by version; pin the dependency in package.json for consistent results across a team.

Practical way to check the result: after editing a TypeScript file, confirm the terminal shows a nodemon restart line and the application behaves as expected. If no restart occurs, check that the edited file extension matches ext in nodemon.json and that the file is not listed in ignore.