init-package-json

8.2.5 · active · verified Sun Apr 19

init-package-json is a Node.js module designed to programmatically and interactively create or update `package.json` files, primarily used by the npm CLI itself. It provides a wizard-like experience for users, prompting for essential package metadata such as name, version, description, entry point, test command, git repository, keywords, author, and license. The current stable version is 8.2.5, with frequent maintenance releases addressing bug fixes and dependency updates, often tied to releases of other `@npmcli` packages. Its key differentiator is its integration with `promzard` for flexible, scriptable prompting and the ability to utilize custom initialization files, offering a powerful way to standardize `package.json` creation across projects or teams. It is a low-level utility most often consumed by package managers rather than directly by end-user applications.

Common errors

```
Error [ERR_REQUIRE_ESM]: require() of ES Module <path/to/module> not supported. Instead change the require of <path/to/module> to a dynamic import() which is available in all CommonJS modules.
```
cause Attempting to `import` `init-package-json` as an ES module in a CommonJS context, or vice-versa, when the package is primarily CommonJS.

fix Use `const init = require('init-package-json')` for CommonJS projects. If in an ESM module, consider `await import('init-package-json')` if the package provides a compatible export, or wrap it in a CommonJS context.
```
Error: The "init-package-json" package requires Node.js version ^20.17.0 || >=22.9.0.
```
cause Running the package with an unsupported Node.js version.

fix Upgrade your Node.js environment to a version compatible with `^20.17.0` or `>=22.9.0`.
```
Error: Cannot find module '<path/to/custom/initFile>'
```
cause The `initFile` path provided to the `init` function is incorrect, or the file does not exist.

fix Double-check the `initFile` path to ensure it is absolute and points to an existing JavaScript file that exports a `promzard` function.

Warnings

breaking Version 8.0.0 introduced significant changes to Node.js compatibility requirements. The package now requires Node.js `^20.17.0 || >=22.9.0`.
Fix: Ensure your Node.js environment meets the specified version requirements. Update Node.js to a compatible version if necessary.
breaking In v8.0.0, a new `type` prompt was added during the interactive initialization process, and the sort order of fields in the created `package.json` file was changed.
Fix: Be aware of the new `type` prompt if using interactive mode. If you rely on a specific field order, be prepared for changes in generated `package.json` files.
gotcha The `initFile` parameter expects a path to a `promzard` module, which is a JavaScript file exporting a function, not a simple JSON configuration file. This allows for dynamic and interactive prompting logic.
Fix: If providing a custom `initFile`, ensure it's a valid `promzard` script that exports a function with the expected signature `(data, cb) => {}` and utilizes the `this.config` and `this.package` context for data manipulation.

Install

npm install init-package-json npm
yarn add init-package-json yarn
pnpm add init-package-json pnpm

Imports

init
wrong:
```
import init from 'init-package-json'
```
correct:
```
const init = require('init-package-json')
```
This package is primarily a CommonJS module. While Node.js versions supporting ESM are required, its main entry point is a CommonJS export.
init
```
const init = require('init-package-json')
```
The primary export is a single function, conventionally named 'init', which handles the interactive package.json creation process.
PromZardContext
```
/* PromZard context is implicitly passed. See PromZard documentation. */
```
When using a custom initFile, the `configData` and `package` objects are passed into the `promzard` module's context, accessible as `config` and `package` variables within that file.

Quickstart

This quickstart demonstrates how to programmatically use `init-package-json` to create a `package.json` file in a specified directory, utilizing a custom `promzard` init file to pre-fill common fields and interact with passed configuration data.

const init = require('init-package-json');
const path = require('path');
const fs = require('fs/promises');

async function initializePackage() {
  // Define a temporary custom init file for demonstration purposes
  const tempInitFileContent = `
    module.exports = function (data, cb) {
      data.name = this.basename;
      data.version = '1.0.0';
      data.description = 'A new package initialized via init-package-json!';
      data.main = 'index.js';
      data.scripts = { test: 'echo \"Error: no test specified\" && exit 1' };
      data.license = 'ISC';
      data.author = this.config.author || '';
      cb(null, data);
    };
  `;
  const customInitFilePath = path.join(__dirname, '.npm-init-custom.js');
  await fs.writeFile(customInitFilePath, tempInitFileContent);

  const targetDir = path.join(__dirname, 'my-new-package');
  await fs.mkdir(targetDir, { recursive: true });

  const configData = { author: 'My Name <me@example.com>' };

  try {
    console.log(`Initializing package.json in ${targetDir}...`);
    const resultData = await init(targetDir, customInitFilePath, configData);
    console.log('package.json initialized successfully:');
    console.log(JSON.stringify(resultData, null, 2));
  } catch (error) {
    console.error('Failed to initialize package.json:', error);
  } finally {
    // Clean up the temporary init file
    await fs.unlink(customInitFilePath);
    console.log('Cleaned up temporary init file.');
  }
}

initializePackage();

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