How to read ESLint config from package.json using package-config?

Import the library and call packageConfig with 'eslintConfig' as the namespace. For example, `const config = await packageConfig('eslintConfig');` will retrieve the ESLint configuration object stored under that key in the nearest package.json.

What's the difference between package-config and read-pkg?

package-config is specialized for reading namespaced configuration from package.json with directory traversal, while read-pkg is a general-purpose library for reading any package.json file without focusing on namespaces or automatic search up the directory tree.

Can package-config handle nested package.json files in monorepos?

Yes, it walks up directories to find the closest package.json, but use the skipOnFalse option or adjust cwd to control which file is read. This is useful for tools like electron-builder with separate app and development package.json files.

How to set default configuration values with package-config?

Pass a defaults object in the options parameter. For example, `const config = await packageConfig('myNamespace', { defaults: { enabled: true } });` will use the defaults if the namespace is not found in package.json.

Is package-config compatible with CommonJS modules?

Yes, it supports both ES modules and CommonJS. You can use require() for synchronous access or dynamic imports for async, as the library provides both APIs, though the README examples focus on ES modules.

How to get the path of the package.json file read by package-config?

Use the packageJsonPath utility function by passing the config object returned from packageConfig. It returns the file path, which is helpful for debugging or logging purposes in complex directory structures.

package-config — Package.json Config Utility

What is package-config?

package-config is a Node.js library that retrieves namespaced configuration data from the nearest package.json file in a directory tree. It solves the problem of scattered, hidden configuration files (like .eslintrc) by centralizing tool settings within package.json, making them more visible and manageable. The library automatically walks up parent directories to find the relevant package.json and extracts config under a specified namespace.

Target Audience

Node.js developers and tool authors who need to read configuration from package.json files, especially those building CLI tools, linters, bundlers, or other development utilities that support package.json-based config.

Value Proposition

Developers choose package-config for its simplicity, reliability, and alignment with the trend of storing tool config in package.json. It reduces repository noise, provides both sync and async APIs, and integrates seamlessly with existing Node.js tooling ecosystems.

Get namespaced config from the closest package.json

Use Cases

Best For

Reading ESLint, Babel, or AVA configuration from package.json
Building CLI tools that support package.json-based user settings
Reducing hidden dotfiles in JavaScript/Node.js projects
Implementing namespaced config for custom development tools
Retrieving nested or root-level package.json configuration
Creating tools that need to traverse directory structures for config

Not Ideal For

Tools requiring configuration from multiple file formats (e.g., YAML, TOML)
Applications that need dynamic, real-time config updates without file system reads
Projects with complex validation or transformation rules for configuration data
Environments without package.json, such as browser-only libraries or non-Node.js setups

Pros & Cons

Pros

Centralized Configuration

Eliminates hidden dotfiles like .eslintrc by storing tool settings directly in package.json, reducing repository clutter and improving discoverability, as highlighted in the README's philosophy.

Automatic Directory Traversal

Walks up parent directories to find the closest package.json, ensuring the most relevant config is used without manual path handling, which simplifies nested project structures.

Dual API Support

Provides both synchronous (packageConfigSync) and asynchronous (packageConfig) methods, catering to different Node.js use cases, such as CLI tools or async workflows.

Flexible Search Options

Supports custom cwd, default config fallbacks, and skipOnFalse to ignore configs set to false, offering control over how configuration is retrieved in complex setups.

Cons

Limited to Package.json

Only reads configuration from package.json files, making it unsuitable for tools that need to support other sources like environment variables or separate config files.

No Built-in Validation

Does not validate the structure or schema of the configuration data, requiring users to handle errors manually, which can lead to runtime issues if the config is malformed.

Niche Use Case

Primarily targets Node.js tools that adopt package.json-based config; for broader configuration management, more comprehensive libraries like cosmiconfig might be necessary.

Frequently Asked Questions

What is package-config?

Target Audience

Value Proposition

Use Cases

Best For

Reading ESLint, Babel, or AVA configuration from package.json
Building CLI tools that support package.json-based user settings
Reducing hidden dotfiles in JavaScript/Node.js projects
Implementing namespaced config for custom development tools
Retrieving nested or root-level package.json configuration
Creating tools that need to traverse directory structures for config

Not Ideal For

Tools requiring configuration from multiple file formats (e.g., YAML, TOML)
Applications that need dynamic, real-time config updates without file system reads
Projects with complex validation or transformation rules for configuration data
Environments without package.json, such as browser-only libraries or non-Node.js setups

Pros & Cons

Pros

Centralized Configuration

Eliminates hidden dotfiles like .eslintrc by storing tool settings directly in package.json, reducing repository clutter and improving discoverability, as highlighted in the README's philosophy.

Automatic Directory Traversal

Walks up parent directories to find the closest package.json, ensuring the most relevant config is used without manual path handling, which simplifies nested project structures.

Dual API Support

Provides both synchronous (packageConfigSync) and asynchronous (packageConfig) methods, catering to different Node.js use cases, such as CLI tools or async workflows.

Flexible Search Options

Supports custom cwd, default config fallbacks, and skipOnFalse to ignore configs set to false, offering control over how configuration is retrieved in complex setups.

Cons

Limited to Package.json

Only reads configuration from package.json files, making it unsuitable for tools that need to support other sources like environment variables or separate config files.

No Built-in Validation

Does not validate the structure or schema of the configuration data, requiring users to handle errors manually, which can lead to runtime issues if the config is malformed.

Niche Use Case

Primarily targets Node.js tools that adopt package.json-based config; for broader configuration management, more comprehensive libraries like cosmiconfig might be necessary.

Frequently Asked Questions

package-config

What is package-config?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?

package-config

What is package-config?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?