`typescript` v2.1.4 doesn't like empty `files` in config

[danfuzz]

Line 49 of config.ts runs afoul of the tsconfig checker in v2.1.4 of the TypeScript compiler:

        configFile = {
            config: {
                compilerOptions: {},
                files: [], // <-------------- THIS LINE
            },
        };

https://github.com/TypeStrong/ts-loader/blob/master/src/config.ts#L49

In my project (https://github.com/danfuzz/quillex), I'm getting the error "error TS18002: The 'files' list in config file 'tsconfig.json' is empty." which I've tracked back to this. (Note: I currently work around this by pointing my project at an older version of typescript.)

If I add a dummy entry to the files list, then typescript stops complaining, and things seem to work as expected, e.g.:

        configFile = {
            config: {
                compilerOptions: {},
                files: ['i-really-hope-you-dont-have-a-file-with-this-name'],
            },
        };

I don't know if this is the best solution to the problem, nor if it causes some other problem that I just haven't noticed yet. For the record, totally removing the files binding causes a different error ("error TS18003: No inputs were found in config file 'tsconfig.json'. Specified 'include' paths were '["**/*"]' and 'exclude' paths were '["node_modules","bower_components","jspm_packages"]'.").

typescript has an explicit error code and message for a specified-but-empty files list, so I'm guessing the change in behavior is intentional.

[danfuzz]

Here's the salient part of the stacktrace where the error is thrown:

    at getFileNames (.../node_modules/typescript/lib/typescript.js:64355:41)
    at Object.parseJsonConfigFileContent (.../node_modules/typescript/lib/typescript.js:64304:18)
    at Object.getConfigParseResult (.../node_modules/ts-loader/dist/config.js:70:38)
    at Object.ensureTypeScriptInstance (.../node_modules/ts-loader/dist/instances.js:33:36)
    at Object.loader (.../node_modules/ts-loader/dist/index.js:17:24)

[johnnyreilly]

Hi @danfuzz,

Thanks for posting details of your workaround. That's interesting. That said; there's nothing really that we can usefully do about this - this is the behaviour of the TypeScript compiler as intended (and this is intended - raised an issue with team and had it confirmed)

[danfuzz]

I assume "nothing to do about this" doesn't actually mean that ts-loader will be left broken forever. Is my — admittedly gross — hack pretty much the best that can be done?

[johnnyreilly]

microsoft/TypeScript#11834

[johnnyreilly]

Well you can stay on TypeScript 2.0 but yes that's pretty much it I'm afraid. Ts-loader works on top of TypeScript and we don't intend to implement different behaviour than the compiler for the most part

[johnnyreilly]

(not because we want to be difficult but that way pain lies - if not immediately then soon)

[danfuzz]

(Yeah I get that. I'm not interested in pegging the project to an old version of the compiler.)

I think I'm confused, then. I don't think I'm using ts-loader in an unusual way; that is, I don't get what I'm doing that's different than other users of ts-loader. Like, what should I be doing differently if I want to use TS 2.1?

FWIW, here's where I config ts-loader in my code: https://github.com/danfuzz/quillex/blob/master/server/ClientBundle.js#L93

[danfuzz]

In any case, thanks for the replies and the info.

[johnnyreilly]

No problem. For what it's worth it's totally normal to not specify files at all. See this example: https://github.com/johnnyreilly/proverb-signalr-react/blob/master/tsconfig.json

[danfuzz]

Just as a coda on this: I figured out what the salient difference is between my situation and other projects'. I'd be surprised if I'm the only one who runs into this, so if nothing else the following can serve as a heads-up.

My project is using TS because it includes the module parchment https://github.com/quilljs/parchment, which is written in TS. Parchment is distributed via npm as a prebuilt JS bundle (built using Webpack) and also includes the original .ts files, but it doesn't include a tsconfig.json file in the npm package. I'm choosing to compile the .ts files (and not use the bundle) because I don't want to have a double layer of Webpack loaders (that is, I'm making my own unified bundle of all the client code). That's why I'm using ts-loader.

So, what ts-loader is getting pointed at is a .ts file which doesn't have a tsconfig.json anywhere around it. This means the getConfigFile() call in ts-loader/config.ts ends up falling through and returning that default one with an empty files list. And it looks to me like any time that that happens, the subsequent attempt to run compilation will fail.

What I can do to work around the problem is add a new tsconfig.json file as a peer to the node_modules directory where parchment lands. (I could also drop one in the parchment directory, but if I do that, I'd no longer be using a pristine package from the npm registry.)

[johnnyreilly]

FWIW - it's not advised to ship TS in node_modules - ts-loader actually warns about this now: #399

[danfuzz]

Huh, well that's a bummer too, because ideally I'd love to keep referring to parchment via npm and not have to e.g. pull in its git repo.

[danfuzz]

Actually it's even worse: I don't use parchment directly. I use it because it's a dependency of quill (which isn't written in TS). So, if I have to stop getting Parchment from npm I also have to stop getting Quill from npm (or hand-patch its dependencies somehow).