Ts-node: How to debug SyntaxError: Unexpected token {

[dougludlow]

I'm trying to convert an es6 project over to typescript. However, I'm getting the following error and I don't know how to go about debugging it as there are no files or line numbers emitted:

SyntaxError: Unexpected token {
    at exports.runInThisContext (vm.js:53:16)
    at Module._compile (module.js:387:25)
    at Object.loader (/usr/local/lib/node_modules/ts-node/src/ts-node.ts:224:14)
    at Module.load (module.js:357:32)
    at Function.Module._load (module.js:314:12)
    at Function.Module.runMain (module.js:447:10)
    at Object.<anonymous> (/usr/local/lib/node_modules/ts-node/src/bin/ts-node.ts:110:12)
    at Module._compile (module.js:413:34)
    at Object.Module._extensions..js (module.js:422:10)
    at Module.load (module.js:357:32)

Any suggestions for debugging?

[blakeembrey]

Hmm, are you importing from a JavaScript file or the CLI?

[dougludlow]

I'm using the cli. Basically:

ts-node main.js

(my tsconfig.json has allowJs set to true)

[blakeembrey]

Are any of the files .ts? This appears to be coming from a .ts file - which appears to be really odd. TypeScript is compiling it, but then it's failing to actually execute. Are you compiling for ES6 at all?

[dougludlow]

No, there shouldn't be any ts files yet, I wanted to slowly convert the project over. So I was trying to see if I could just get the es6 to run first.

This is my tsconfig.json:

{
    "compilerOptions": {
        "module": "commonjs",
        "target": "es6",
        "noImplicitAny": false,
        "sourceMap": false,
        "allowJs": true
    },
    "exclude": [
        "node_modules"
    ]
}

I've literally just installed ts-node and added a tsconfig.json and tried to run it. Not sure if it's a valid use case, but I'm trying to find an easy way to transition a project from es6 to typescript.

[blakeembrey]

Ok, I see. Was it running on node before, or were you using Babel? The odd thing here is that ts-node doesn't even do anything on non-.ts files, so nothing here should be going through TypeScript at all.

[dougludlow]

Yeah, just running it on node.

Ha, that is odd, yeah, no typescript whatsoever at this point.

[dougludlow]

I tried changing my main.js to main.ts and running it, but it imports other js files obviously and I end up seeing the same error SyntaxError: Unexpected token {.

[blakeembrey]

To confirm, everything works fine when you do node main.js?

[dougludlow]

Good catch! When I run the app, I'm doing electron main.js (it's an electron app), running node main.js throws:

/Users/doug/Projects/inofile/kno2-electron/main.js:4
const { SocketHandler, IpcHandler, SquirrelHandler } = require('./lib/handlers');
      ^

SyntaxError: Unexpected token {
    at exports.runInThisContext (vm.js:53:16)
    at Module._compile (module.js:387:25)
    at Object.Module._extensions..js (module.js:422:10)
    at Module.load (module.js:357:32)
    at Function.Module._load (module.js:314:12)
    at Function.Module.runMain (module.js:447:10)
    at startup (node.js:139:18)
    at node.js:999:3

Which is the error we're seeing. Apparently this is a non issue, ha ha. Thanks for your time. :+1:

[SagnikPradhan]

Was facing the same error, in my case it was because ts-node was picking up the tsconfig.json from current directory and not the one I was expecting, cause of that it compiled the script into esm which does not work on node without the flag.