using checkJs breaks intellisense on a deep require with no declaration file

[jkantr]

TypeScript Version: 3.3.0-dev.20181204

Search Terms: checkjs allowjs breaks intellisense code completion

Code
Without checkJs turned on

With checkJs turned on

Expected behavior: With or without checkJs being on, intellisense should otherwise be able to infer the same code types for completion, even if a module being required doesn't have a typings file or module definition.

Actual behavior:
All intellisense / code completion is completely lost when checkJs is turned on but a required module doesn't have declarations.

After trying to find some guidance on the Gitter, I was told to lodge this here. By "checkJs" turned on, I mean here is my .tsconfig:

{
    "compilerOptions": {
        "outDir": "./built",
        "allowJs": true,
        "target": "es2018",
        "checkJs": true,
        "module": "commonjs",
        "esModuleInterop": true,
        "allowSyntheticDefaultImports": true
    }
}

[DanielRosenwasser]

Do you have a self-contained reproduction here at all? Are there any other files?

[jkantr]

@DanielRosenwasser sorry, I should have done this initially, here's a repro (of sorts...):

https://github.com/jkantr/ts-checkjs-intellisense-repro

Just clone, npm install, and then open index.js and follow the 2 commented lines of instructions.

This isn't quite a "minimal" case as it uses the real-world lib that i encountered the issue with. But the repro itself is minimal. Let me know if this is "good enough"... otherwise I'll have to figure out how to create a minimal example of what the library is doing.

[sandersn]

@jkantr I can't repro this with your provided repo on typescript@next. I get no completions regardless of checkJs' setting. Do you still observe this difference between checkJs on and off?

Adding "maxNodeModuleJsDepth": 5 does make things work; perhaps the problem is that @node-sc2 has a d.ts but it isn't complete so you often want to reference the .js files directly, even though they are nested deeply. maxNodeModuleJsDepth is an obscure setting that instructs TS to get types from .js files when d.ts files are not available. The value of the setting is how many imports to follow before giving up, so 1 or 2 might be enough to make it work here.