tsc-watch
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gilamran
The TypeScript compiler with --watch and a new onSuccess argument
The nodemon for TypeScript
tsc-watch starts a TypeScript compiler with --watch parameter, with the ability to react to compilation status.
tsc-watch was created to allow an easy dev process with TypeScript. Commonly used to restart a node server, similar to nodemon but for TypeScript.
| Argument | Description |
|---|---|
--onSuccess COMMAND |
Executes COMMAND on every successful compilation. |
--onFirstSuccess COMMAND |
Executes COMMAND on the first successful compilation. |
--onFailure COMMAND |
Executes COMMAND on every failed compilation. |
--onCompilationStarted COMMAND |
Executes COMMAND on every compilation start event (initial and incremental). |
--onCompilationComplete COMMAND |
Executes COMMAND on every successful or failed compilation. |
--maxNodeMem |
Calls node with a specific memory limit max_old_space_size, to use if your project needs more memory. |
--noColors |
By default tsc-watch adds colors the output with green on success, and in red on failure. Add this argument to prevent that. |
--noClear |
In watch mode the tsc compiler clears the screen before reportingAdd this argument to prevent that. |
--silent |
Do not print any messages on stdout. |
--compiler PATH |
The PATH will be used instead of typescript compiler.Default is typescript/bin/tsc |
Notes:
-
That all the above
COMMANDs will be killed on process exit. (UsingSIGTERM) -
A
COMMANDis a single command and not multi command likescript1.sh && script2.sh -
Any child process (
COMMAND) will be terminated before creating a new one.
Install
npm install tsc-watch --save-dev
## for command-line usage
npm install -g typescript tsc-watch
Usage
From Command-Line
## Watching a project (with tsconfig.json)
tsc-watch --onSuccess "node ./dist/server.js"
## Beep on failure
tsc-watch --onFailure "echo Beep! Compilation Failed"
## Watching a single file
tsc-watch server.ts --outDir ./dist --onSuccess "node ./dist/server.js"
## Custom compiler
tsc-watch --onSuccess "node ./dist/server.js" --compiler my-typescript/bin/tsc
From npm script
"dev-server": "tsc-watch --noClear -p ./src/tsconfig.json --onSuccess \"node ./dist/server.js\"",
From javascript
You can see a detailed example here
The client is implemented as an instance of Node.JS's EventEmitter, with the following events:
started- Emitted upon the compilation start (initial or incremental).first_success- Emitted upon first successful compilation.subsequent_success- Emitted upon every subsequent successful compilation.compile_errors- Emitted upon every failing compilation.file_emitted- Emitted upon every file transpiled if--listEmittedFilesis used.
Once subscribed to the relevant events, start the client by running watch.start()
To kill the client, run watch.kill()
Example usage:
const TscWatchClient = require('tsc-watch/client');
const watch = new TscWatchClient();
watch.on('started', () => {
console.log('Compilation started');
});
watch.on('first_success', () => {
console.log('First success!');
});
watch.on('success', () => {
// Your code goes here...
});
watch.on('compile_errors', () => {
// Your code goes here...
});
watch.start('--project', '.');
try {
// do something...
} catch (e) {
watch.kill(); // Fatal error, kill the compiler instance.
}
Notes:
- The (
onSuccess)COMMANDwill not run if the compilation failed. tsc-watchis using the currently installed TypeScript compiler.tsc-watchis not changing the compiler, just adds the new arguments, compilation is the same, and all other arguments are the same.
gilamran