ts-node-dev

Tweaked version of node-dev that uses ts-node under the hood.

It restarts target node process when any of required files changes (as standard node-dev) but shares Typescript compilation process between restarts. This significantly increases speed of restarting comparing to node-dev -r ts-node/register ..., nodemon -x ts-node ... variations because there is no need to instantiate ts-node compilation each time.

Install

yarn add ts-node-dev --dev

npm i ts-node-dev --save-dev

Usage

ts-node-dev [node-dev|ts-node flags] [ts-node-dev flags] [node cli flags] [--] [script] [script arguments]

So you just combine node-dev and ts-node options (see docs of those packages):

ts-node-dev --respawn --transpile-only server.ts

There is also short alias tsnd for running ts-node-dev:

tsnd --respawn server.ts

Look up flags and options can be used in ts-node's docs.

Also there are additional options specific to ts-node-dev:

--ignore-watch - (default: []) - files/folders to be ignored by node-dev. But this behaviour is enhanced: it also supports regular expression in the ignore strings and will check absolute paths of required files for match.
--deps - Also watch node_modules; by default watching is turned off
--debug - Some additional [DEBUG] output
--quiet - Silent [INFO] messages
--interval - Polling interval (ms) - DOESN'T WORK CURRENTLY
--debounce - Debounce file change events (ms, non-polling mode)
--clear (--cls) - Will clear screen on restart
--watch - Explicitly add arbitrary files or folders to watch and restart on change (list separated by commas, chokidar patterns)
--exit-child - Adds 'SIGTERM' exit handler in a child process.
--rs - Allow to restart with "rs" line entered in stdio, disabled by default.
--notify - to display desktop-notifications (Notifications are only displayed if node-notifier is installed).
--cache-directory - tmp dir which is used to keep the compiled sources (by default os tmp directory is used)

If you need to detect that you are running with ts-node-dev, check if process.env.TS_NODE_DEV is set.

Points of notice:

If you want desktop-notifications you should install node-notifier package and use --notify flag.
Especially for large code bases always consider running with --transpile-only flag which is normal for dev workflow and will speed up things greatly. Note, that ts-node-dev will not put watch handlers on TS files that contain only types/interfaces (used only for type checking) - this is current limitation by design.
--ignore-watch will NOT affect files ignored by TS compilation. Use --ignore option (or TS_NODE_IGNORE env variable) to pass RegExp strings for filtering files that should not be compiled, by default /node_modules/ are ignored.
Unknown flags (node cli flags are considered to be so) are treated like string value flags by default. The right solution to avoid ambiguity is to separate script name from option flags with --, for example:
```
ts-node-dev --inspect -- my-script.ts
```
The good thing is that ts-node-dev watches used tsconfig.json file, and will reinitialize compilation on its change, but you have to restart the process manually when you update used version of typescript or make any other changes that may effect compilation results.

Issues

If you have an issue, please create one. But, before:

try to check if there exits alike issues.
try to run your code with just ts-node
try to run your code with --files option enabled (see ts-node docs)
try to run it with --debug flag and see the output
try to make create repro example

Versioning

Currently versioning is not stable and it is still treated as pre-release. You might expect some options API changes. If you want to avoid unexpected problems it is recommended to fixate the installed version and update only in case of issues, you may consult CHANGELOG for updates.

License

MIT.

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