Combine JavaScript code with its corresponding TypeScript definition located in separate files

Question

Combine JavaScript code with its corresponding TypeScript definition located in separate files

I am trying to utilize a specific file from a repository without the need to install its NPM package. This particular file was written in JavaScript and has a separate definition file.

The JavaScript file contains an export for the Headers class.
The TypeScript definition file provides the type definition for the Headers class.

In order to combine the JavaScript implementation with the type definition, I came up with this strategy:

import { default as HeadersImplementation } from '../node-fetch/src/headers.js';
import { Headers as HeadersDefinition, HeadersInit } from '../node-fetch/@types/index';

const Headers: {
  prototype: HeadersImplementation;
  new(init?: HeadersInit): HeadersDefinition;
} = HeadersImplementation;

const test = new Headers();
test.append('Hello', 'World!');

Is there a straightforward way to merge the class implementation with its definition?

typescript typescript-typings

Answer 1

Answer №1

To ensure clean and efficient use in other modules, I recommend re-exporting it:

Make sure to also re-export the HeadersInit type for precise typing of constructor input arguments.

./src/headers.ts:

// @ts-ignore
import {default as HeadersImplementation} from '../node-fetch/src/headers.js';
import {type Headers} from '../node-fetch/@types/index';
export {type HeadersInit} from '../node-fetch/@types/index';

const H: typeof Headers = HeadersImplementation;
export {H as Headers};

./src/index.ts:

import {Headers, type HeadersInit} from './headers.js';

const init: HeadersInit = [['name', 'value']];
const test = new Headers(init);
test.append('Hello', 'World!');
console.log([...test]);

$ tsc && node dist/index.js
[ [ 'hello', 'World!' ], [ 'name', 'value' ] ]

Answer 2

To ensure clean and efficient use in other modules, I recommend re-exporting it:

Make sure to also re-export the HeadersInit type for precise typing of constructor input arguments.

./src/headers.ts:

// @ts-ignore
import {default as HeadersImplementation} from '../node-fetch/src/headers.js';
import {type Headers} from '../node-fetch/@types/index';
export {type HeadersInit} from '../node-fetch/@types/index';

const H: typeof Headers = HeadersImplementation;
export {H as Headers};

./src/index.ts:

import {Headers, type HeadersInit} from './headers.js';

const init: HeadersInit = [['name', 'value']];
const test = new Headers(init);
test.append('Hello', 'World!');
console.log([...test]);

$ tsc && node dist/index.js
[ [ 'hello', 'World!' ], [ 'name', 'value' ] ]

Answer 3

Answer №2

There is no need to modify any part of the existing code or attempt to integrate it with your own code. Simply ensure that you have two files with matching names and import what you require into your code.

Your project only requires 2 installations, which may already be present.

Follow these steps:

Save the js file in a folder within your project
Save the .d.ts file in the same folder and rename both files with identical names; for example, headers.js and headers.d.ts
Install typescript if not already installed: npm i -D typescript (you may have already completed this step)
Install the typings module: npm install --save @types/node
Proceed to import the necessary components:
```
import {Headers} from "./headers.js"
```
Utilize the provided types in your code

Additionally, you can:

Move all files from the src folder to a preferred location; consider using node-fetch
Include index.d.ts in this folder to access node-fetch types
Import directly from the new folder:
```
import {Headers} from "./node-fetch"
```

Answer 4

There is no need to modify any part of the existing code or attempt to integrate it with your own code. Simply ensure that you have two files with matching names and import what you require into your code.

Your project only requires 2 installations, which may already be present.

Follow these steps:

Save the js file in a folder within your project
Save the .d.ts file in the same folder and rename both files with identical names; for example, headers.js and headers.d.ts
Install typescript if not already installed: npm i -D typescript (you may have already completed this step)
Install the typings module: npm install --save @types/node
Proceed to import the necessary components:
```
import {Headers} from "./headers.js"
```
Utilize the provided types in your code

Additionally, you can:

Move all files from the src folder to a preferred location; consider using node-fetch
Include index.d.ts in this folder to access node-fetch types
Import directly from the new folder:
```
import {Headers} from "./node-fetch"
```

Combine JavaScript code with its corresponding TypeScript definition located in separate files

Answer №1

Answer №2

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