HTTP Core Constants Library

Common errors

• TypeError: Cannot read properties of undefined (reading 'ACCEPT')

  cause This typically occurs when attempting to access a named export from a CommonJS `require` statement without explicitly destructuring it, or when using an incorrect import path.
  fix For ESM, ensure named imports are used: `import { HttpHeaders } from 'http-core-constants';`. For CommonJS (if using an older version or transpiled code), ensure destructuring: `const { HttpHeaders } = require('http-core-constants');`.

• TypeError: HttpHeaders is not a constructor

  cause The constants (e.g., `HttpHeaders`, `HttpStatus`) are exported as enums (or plain objects in older versions) and are not intended to be instantiated with `new`.
  fix Access constants directly as properties of the imported enum/object, for example: `HttpHeaders.ACCEPT` or `HttpStatus.SC_OK`.

Warnings

• breaking Version 1.3.0 converted all constant modules (HttpHeaders, HttpStatus, HttpRequestMethod) from plain objects to TypeScript enum declarations. This change can impact consumers relying on object-like behaviors such as iteration over properties or dynamic property access, and may alter runtime types for some JavaScript environments.
  Fix: Review code that interacts with these constants, especially if performing operations typically applied to plain objects. Ensure correct enum usage in TypeScript, and be aware of potential runtime differences in JavaScript if reflection or dynamic property listing was previously used.
• gotcha The `http-core-constants` package has not been updated since February 2020. This indicates the package is likely abandoned and will not receive updates for new HTTP standards, bug fixes, or security patches. Consider using more actively maintained alternatives for critical projects.
  Fix: Evaluate alternative HTTP constant libraries such as `http-status-codes` or `@poppanator/http-constants` which are actively maintained and support more recent HTTP specifications and features.

Install

• npm install http-core-constants npm
• yarn add http-core-constants yarn
• pnpm add http-core-constants pnpm

Imports

• HttpHeaders
  wrong:

  const HttpHeaders = require('http-core-constants').HttpHeaders;

  correct:

  import { HttpHeaders } from 'http-core-constants';

  Since v1.3.0, HttpHeaders is an enum; use named import.
• HttpStatus
  wrong:

  const HttpStatus = require('http-core-constants').HttpStatus;

  correct:

  import { HttpStatus } from 'http-core-constants';

  Since v1.3.0, HttpStatus is an enum; use named import. Both `SC_OK` and `OK` forms are available.
• HttpRequestMethod
  wrong:

  const HttpRequestMethod = require('http-core-constants').HttpRequestMethod;

  correct:

  import { HttpRequestMethod } from 'http-core-constants';

  Since v1.3.0, HttpRequestMethod is an enum; use named import.

Quickstart

Demonstrates importing and using various HTTP constants for headers, status codes, and request methods.

import { HttpHeaders, HttpStatus, HttpRequestMethod } from 'http-core-constants';

console.log(`Accept header: ${HttpHeaders.ACCEPT}`);
console.log(`OK status code (SC_OK): ${HttpStatus.SC_OK}`);
console.log(`OK status code (OK): ${HttpStatus.OK}`);
console.log(`HTTP GET method: ${HttpRequestMethod.GET}`);

// Example using status code in a mock response
class MockHttpResponse {
    status: HttpStatus;
    constructor(status: HttpStatus) {
        this.status = status;
    }
    send(body: string) {
        console.log(`Sending response with status ${this.status}: ${body}`);
    }
}

const response = new MockHttpResponse(HttpStatus.OK);
response.send('Operation successful!');