Update index.d.ts

[ricardo-cavalheiro]

Support plan

• which support plan is this issue covered by? (e.g. Community, Sponsor, or Enterprise): Community
• is this issue currently blocking your project? (yes/no): no
• is this issue affecting a production system? (yes/no): no

Context

• node version: 16.9
• module (formidable) version: 1.2.2
• environment (e.g. node, browser, native, OS): node
• used with (i.e. popular names of modules): typescript
• any other relevant information:

What are you trying to achieve or the steps to reproduce?

I was trying to access the path property from the files parameter, but I got the commented error below:

import express from "express";
import formidable from "formidable";
import path from "path";

const app = express();

app.get("/", (req, res) => {
  return res.send("working");
});

app.post("/photo", (req, res) => {
  const form = formidable({
    keepExtensions: true,
    uploadDir: path.resolve("./storage/img"),
  });

  form.parse(req, (error, formName, files) => {
    if (error) {
      console.error("There was an error while parsing the file: " + error);

      return res.status(500).send("did'nt work");
    }

    // Property 'path' does not exist on type 'File | File[]'.
    // Property 'path' does not exist on type 'File[]'.ts(2339)
                                             vv
    return res.status(201).send(files.image.path);
  });
});

app.listen(5678);

What was the result you got?

At runtime, I get the path value, but TS complains about path not being defined when I'm coding.

What result did you expect?

I expect TS to understand that sometimes I get only one file, not an array of files.

The workaround I found is: you need to install the types for formidable with @types/formidable, go to index.d.ts and, at line 180, change:

interface Files {
  [file: string]: File | Files[];
}

to:

interface Files {
  [file: string]: File;
}

I decided to remove the Files[] because I noticed that when form parses a request with more than one image, it does not put the images inside an array but inside a literal object. Therefore, you can access any of these images by using the input's name property in the form tag.

I create a repo to show this issue here.

[GrosSacASac]

In version 3.x it is always an array