Auto import not working for lodash

[mjbvz]

From microsoft/vscode#63239

TypeScript Version: 3.3.0-dev.20181214

Search Terms:

• auto import
• suggestions / completions

Code

1. For a simple js project that has lodash installed under node_modules
2. In a blank js file, type: kebabCase

Expected behavior:
Auto import suggestion to import from lodash returned

Actual behavior:
No suggestion returned

[shayded-exe]

To add to this, it does work once you already have an existing import from lodash in the file. The suggestions don't show up in auto-complete, but it does give a quick fix suggest to add the new method to the existing import from lodash.

[aleclarson]

This issue provides a repro: microsoft/vscode#67505

[sheetalkamat]

This issue is duplicate of #28773 wherein during completion we don't have knowledge of symbols not in the program and hence no offering in the completions.

[aleclarson]

@sheetalkamat It's a little surprising that TypeScript doesn't anticipate that a package listed in dependencies will eventually be imported by the program. Is this on the roadmap?

[tnrich]

Even when I am using lodash in a file I still don't get auto-import for it. Here is an image showing it not working:

Lodash is really the only module I see this not working well for.

[tnrich]

Any update on this one? This is definitely something I get annoyed by on a near daily basis. I am just continually surprised that this feature which works so well for most other packages doesn't work for the single most popular js library:

Either vscode is doing something wrong or lodash is but it seems really odd that this has been an issue for so long

[tnrich]

lodash/lodash#4062

[aleclarson]

@tnrich Do you know of a library (that takes a similar approach for its .d.ts definitions) that works as expected?

[tnrich]

@aleclarson I'm not sure how lodash's .d.ts files are defined. Could you elaborate more?

Do lodash's types get pulled from https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/lodash by default?

[aleclarson]

@tnrich I dove into @types/lodash to find that export = _ is the issue.

Removing that line is the first step. The problem is that it can't be removed, because
import _ = require('lodash') is probably being used by someone.

The other step is to add an export const line for each Lodash function, though I wonder if something like export * from _.LodashStatic is (or should be) possible. Maybe export as namespace _ is supposed to be doing that?

Not sure if this is an issue with TypeScript itself, or just @types/lodash.

[tnrich]

Hmm thanks for diving in @aleclarson. I poked around as well but am not super familiar with typescript so felt a bit lost.

I agree that import _ = require('lodash') is definitely being used by many but there is probably a workaround that allows both.

Is there someone we can ask about this? Maybe one of the @types/lodash maintainers?

@Andy-MS @aj-r -- I couldn't find a list of maintainers but it looks like you both have committed a fair amount to the @types/lodash repo. Could either of you comment on this issue? Thank you 🙏