How to feed .js files to TypeScript when the allowJs flag is provided?

[kruncher]

Looking at the source for ts-node I see that it filters against the extensions .ts and .tsx.

In my case I would like it to also treat the .js extension in this way but only within a certain path of my node application since I do not want any .js scripts from within node_modules to be put through the TypeScript compiler in this way.

Is there a way to do this that I am perhaps missing?

Many thanks!

[blakeembrey]

No, it's not possible today. It would be a nice addition.

[kruncher]

👍 Awesome stuff! thanks :)

[blakeembrey]

@kruncher If you get a chance, I'd love for someone to test it before I release 😄

[kruncher]

@blakeembrey I am trying to get this to work but having difficulties with passing the --allowJs argument to the command line. Here are things that I have tried:

λ mocha --require ts-node/register --allowJs
  error: unknown option `--allowJs'
λ mocha --require ts-node/register --project ./test/tsconfig.json
  error: unknown option `--project'
λ mocha --require ts-node/register --compilerOptions '{ "allowJs": true }'
  Error: cannot resolve path (or pattern) 'allowJs:'

I suspect that I am not properly understanding the instructions on the readme page.

[blakeembrey]

@kruncher You can not pass options into a Mocha register like that. It expects a file, so you're just passing options to mocha instead. The only workarounds using that syntax would be to use environment variables or set it in tsconfig.json.

[kruncher]

@blakeembrey I created a script file to register ts-node, startup mocha and then start the test running process and it seems to be working 😃

There was one slight false alarm:

TSError: ⨯ Unable to compile TypeScript
Cannot write file '/abc/test/Test.js' because it would overwrite input file. (5055)
Cannot write file '/abc/test/main.js' because it would overwrite input file. (5055)
test\main.js: Emit skipped

I was able to take the batteries out by specifying a path for outDir for the compilerOptions when registering ts-node. No output was generated but it does seem like an unnecessary error message.

It would be really awesome if there were a way to set up ts-node to work with mocha without having to create the bootstrap; perhaps with the environment variables.

Here is the bootstrap script that I threw together to try this out:

// /abc/scripts/test.js

require('ts-node').register({
  compilerOptions: {
    outDir: "../test-js",
    allowJs: true
  }
});

// from: https://github.com/mochajs/mocha/wiki/Using-mocha-programmatically
var Mocha = require('mocha'),
  fs = require('fs'),
  path = require('path');

// Instantiate a Mocha instance.
var mocha = new Mocha();

var testDir = path.join(__dirname, '../test');

// Add each .js file to the mocha instance
fs.readdirSync(testDir).filter(function(file){
  // Only keep the .js files
  return file.substr(-3) === '.js';

}).forEach(function(file){
  mocha.addFile(
    path.join(testDir, file)
  );
});

// Run the tests.
mocha.run(function(failures){
  process.on('exit', function () {
    process.exit(failures);  // exit with non-zero status if there were failures
  });
});

[blakeembrey]

@kruncher Thanks for the catch, I've run into this on another module before. I think we just need to fake the outDir for now, I'll patch this ASAP.

[blakeembrey]

@kruncher Did you want to try https://github.com/TypeStrong/ts-node/releases/tag/v0.9.1?

[kruncher]

@blakeembrey Awesome stuff; the outDir fix works great 😃

Cheers!