An error occurred while trying to read the map file

[dan-j]

Using version 1.1.1, I get the following error and can't get round it. Downgrading to 1.1.0 fixes the issue.

It's reproducible on the most trivial example:

$ yarn add -D ts-babel-node

index.ts:

console.log('hello world');

$ ts-babel-node index.ts

/repo/node_modules/convert-source-map/index.js:40
    throw new Error('An error occurred while trying to read the map file at ' + filepath + '\n' + e);
    ^

Error: An error occurred while trying to read the map file at /repo/data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoiL1VzZXJzL0Rhbi9Eb2N1bWVudHMvZ2l0X3JlcG9zL3RzLXJlYWN0LWV4cHJlc3Mtc3RhcnRlci9pbmRleC50cyIsInNvdXJjZXMiOlsiL1VzZXJzL0Rhbi9Eb2N1bWVudHMvZ2l0X3JlcG9zL3RzLXJlYWN0LWV4cHJlc3Mtc3RhcnRlci9pbmRleC50cyJdLCJuYW1lcyI6W10sIm1hcHBpbmdzIjoiO0FBQUEsT0FBTyxDQUFDLEdBQUcsQ0FBQyxhQUFhLENBQUMsQ0FBQyIsInNvdXJjZXNDb250ZW50IjpbImNvbnNvbGUubG9nKCdoZWxsbyB3b3JsZCcpO1xuIl19
Error: ENOENT: no such file or directory, open '/repo/data:application/json;charset=utf-8;base64,eyJ2ZXJzaW9uIjozLCJmaWxlIjoiL1VzZXJzL0Rhbi9Eb2N1bWVudHMvZ2l0X3JlcG9zL3RzLXJlYWN0LWV4cHJlc3Mtc3RhcnRlci9pbmRleC50cyIsInNvdXJjZXMiOlsiL1VzZXJzL0Rhbi9Eb2N1bWVudHMvZ2l0X3JlcG9zL3RzLXJlYWN0LWV4cHJlc3Mtc3RhcnRlci9pbmRleC50cyJdLCJuYW1lcyI6W10sIm1hcHBpbmdzIjoiO0FBQUEsT0FBTyxDQUFDLEdBQUcsQ0FBQyxhQUFhLENBQUMsQ0FBQyIsInNvdXJjZXNDb250ZW50IjpbImNvbnNvbGUubG9nKCdoZWxsbyB3b3JsZCcpO1xuIl19'
    at readFromFileMap (/repo/node_modules/convert-source-map/index.js:40:11)
    at new Converter (/repo/node_modules/convert-source-map/index.js:47:32)
    at Object.exports.fromMapFileComment (/repo/node_modules/convert-source-map/index.js:110:10)
    at Object.exports.fromMapFileSource (/repo/node_modules/convert-source-map/index.js:122:22)
    at Module.compile (/repo/node_modules/ts-babel-node/index.js:46:36)
    at Module.<anonymous> (/repo/node_modules/ts-babel-node/index.js:89:15)
    at Module.m._compile (/repo/node_modules/ts-node/dist/index.js:219:29)
    at Module._extensions..js (module.js:580:10)
    at require.extensions.(anonymous function) (/repo/node_modules/ts-node/dist/index.js:221:16)
    at Object.hook (/repo/node_modules/ts-babel-node/index.js:42:3)

[dan-j]

The first line of this function Line 56 seems to be the culprit:

function compile(base, code, filename) {
  var sourcemap = convertSourceMap.fromMapFileSource(code, '.').toObject();
  code = convertSourceMap.removeMapFileComments(code);

  var babelOutput = babel.transform(code, getBabelOpts(filename, sourcemap));

  // babelOutput has a bunch of undocumented stuff on it. Just grab what we need to save memory
  outputs[filename] = { code: babelOutput.code, map: babelOutput.map };

  return base.call(this, babelOutput.code, filename);
}

This tries to extract a file name from the source-map comment, however this module outputs source-maps as base64 encoded comments. Changing line 56 to the following fixes the issue:

<   var sourcemap = convertSourceMap.fromMapFileSource(code, '.').toObject();
---
>   var sourcemap = convertSourceMap.fromSource(code).toObject();

Happy to make a pull request, although I'd like to know how this issue doesn't already exist because it's made the module absolutely unusable for myself.

[dan-j]

I've found out what's caused the issue in the first place.

I was using the most recent version of ts-node 3.2.0, ts-babel-node requires ^3.0.6. In 3.1.0 there was a change which emitted source-maps inline rather than to a separate file cache.

I've forked the repo and intend on making the fix and upgrading to ts-node 3.2.0.

[dan-j]

Ok, you can't upgrade to 3.2.0 because there's a bug where it doesn't work for .tsx files.

https://github.com/TypeStrong/ts-node/issues/393

Will leave this here for now, wait until ts-node have fixed their issues

[n8agrin]

Cheers! This unblocked me after a few hours of tearing my hair out!

[pumano]

I got the same problem, any news about fix?

[dan-j]

Pretty sure the creator isn't active on this anymore, I've had a Pull Request open since July which hasn't been looked at.

I'd say fork my fork https://github.com/dan-j/ts-babel-node (don't use mine, I might forget and delete it someday) it was July when I last committed to it but it fixes the issues discussed here. I'm no longer using it so won't be active on it, but I'll respond to messages if need be.