Include typings for Typescript, for V2/V3 of Formidable

[gboer]

Support plan

• which support plan is this issue covered by?: Community
• is this issue currently blocking your project?: Yes
• is this issue affecting a production system?: Yes

Context

• node version: v14.18.1
• module (formidable) version: Any V2/V3
• environment (e.g. node, browser, native, OS): NodeJS
• used with (i.e. popular names of modules): Typescript 4.X
• any other relevant information: N/A

What problem are you trying to solve?

I am trying to upgrade to Formidable V2 or V3, but since there are no typings available for this version, it is incredibly time-consuming to figure out how the API looks and what I need to place where. Since this project is downloaded millions of times per week, I can only assume that a lot of other people are running into the same issue. This makes adopting the new version unlikely, any time soon.

Do you have a new or modified API suggestion to solve the problem?

Include the typings with the new version.

[GrosSacASac]

@karlhorky I saw you helped with types in the past, what should we do ?

[karlhorky]

Thanks for the ping! I also ran into this problem when upgrading (since the internals of v2 are incompatible with v1).

I fixed the problems that I encountered just as a patch (using patch-package in my local repository):

diff --git a/node_modules/@types/formidable/index.d.ts b/node_modules/@types/formidable/index.d.ts
index 249da05..e4b4e50 100755
--- a/node_modules/@types/formidable/index.d.ts
+++ b/node_modules/@types/formidable/index.d.ts
@@ -208,12 +208,12 @@ declare namespace formidable {
          * The path this file is being written to. You can modify this in the `'fileBegin'` event in case
          * you are unhappy with the way formidable generates a temporary path for your files.
          */
-        path: string;
+        filepath: string;
 
         /**
          * The name this file had according to the uploading client.
          */
-        name: string | null;
+        originalFilename: string | null;
 
         /**
          * The mime type of this file, according to the uploading client.

But of course this is not a solution for everyone... so continuing in the next comment 👇

[karlhorky]

So I would ask you, @GrosSacASac and @tunnckoCore, would the maintainers of formidable be open to either of the following:

1. Converting the project to TypeScript (or JSDoc + .d.ts files)
2. Maintaining types as part of the formidable package

A less desirable alternative would be:

3. Supporting the DefinitelyTyped community (the people who maintain @types/formidable) in PRs like fix(formidable): attempt to amend changes from #51364 DefinitelyTyped/DefinitelyTyped#52697

---

Oh and for people who are looking for a solution, @gboer has opened a PR to DefinitelyTyped to add the new types 👍 Thanks!

DefinitelyTyped/DefinitelyTyped#56925

[gboer]

hehe yeah, I was about to add that :) But there are no types for v3 yet and in the long run, it would still be nice if the typings would be delivered with formidable itself. Makes things a lot simpler for everyone.

[karlhorky]

Yeah easiest long term and most beneficial would be if formidable@3 would be written in TypeScript.

[GrosSacASac]

Yes, as I said here #500 I would welcome if someone makes a PR to add types in formidable. If one of you wants I can also give github formidable access so you can make a branch instead of a fork to make a PR.

[tunnckoCore]

yes, totally. vould be rewritten to typescript, I'm open for that.

[gboer]

small update, the types for Formidable V2 are now available in @types/formidable@2.0.0 :)

[tunnckoCore]

@gboer great! :)

I'm for rewriting it to TypeScript with both hands, also moving to a monorepo #569. I didn't write a lot of code last year or more, so.. starting a rewrite in typescript could be incredibly tricky for me 🤣 me and typescript ... ah, it's hard relationship through the years hahaha

[Akxe]

I will happily convert v3 to a typesafe version, but I could not find the branch 😁

PS: Found it, began the work 😊

[tunnckoCore]

@Akxe v3 is master already, you can start from there. I'll soon bump npm latest to v3 too.

[Akxe]

The typescript rewrite is quite hard without major changes to the codebase. There is a lot of Object.assign(this, ...) and a lot of sharing of the this "variable".

I would usually do either:

Parsers/plugins as standalone classes

that do not share anything with the Formidable/IncommingForm class

They would expose API that the Formidable would call and then either get a one-time result, a generator function, or even EventEmmiter back.

Parsers as an extension of Formidable

This is an option too, I did not finish looking through the plugin code in-depth yet.

---

Please before v3 is marked as latest edit README.MD with info, that you need to install v2 in order for webpack and probably similar to work.

[tunnckoCore]

@Akxe they already are extensions/plugins.

There is a lot of Object.assign(this, ...) and a lot of sharing of the this "variable".

No problemo. The this use was intentional, but they work without it too.

Please before v3 is marked

Good point.

[wbt]

You may want to merge this before treating anything from the types repo as a starting point, FYI.