pkg-to-jsr 🚀

pkg-to-jsr is a zero-config generator that creates a jsr.json file from your existing package.json.

It simplifies the process of preparing your package for publication on JSR.

✨ Features

• 🔧 Zero configuration required - just run and go!
• 🪄 Automatically generates jsr.json from package.json
• 📦 Handles complex exports configurations with ease
• 🎯 Supports include and exclude options for precise publishing control
• 🚀 Streamlines your workflow for JSR publication

📥 Installation

You can use pkg-to-jsr without installation using npx:

1npx pkg-to-jsr

Alternatively, you can use other package managers:

1# Using Yarn
2yarn dlx pkg-to-jsr
3
4# Using pnpm
5pnpm dlx pkg-to-jsr
6
7# Using Bun
8bunx pkg-to-jsr

For global installation:

1npm install -g pkg-to-jsr

🚀 Usage

Run the following command in your project directory:

1npx pkg-to-jsr

This will generate a jsr.json file based on your package.json.

Options

• --root <path>: Specify the root directory containing the package.json file (default: current working directory)

📚 Examples

Here are some examples of how pkg-to-jsr transforms your package.json into jsr.json:

Basic Example

package.json:

1{
2	"name": "package",
3	"jsrName": "@scope/package",
4	"version": "1.0.0",
5	"exports": "./index.js"
6}

Generated jsr.json:

1{
2	"name": "@scope/package",
3	"version": "1.0.0",
4	"exports": {
5		".": "./index.js"
6	}
7}

Complex Exports Example

package.json:

1{
2	"name": "package",
3	"author": "ryoppippi",
4	"version": "1.0.0",
5	"exports": {
6		".": {
7			"jsr": "./src/index.ts",
8			"import": "./dist/index.js",
9			"types": "./dist/index.d.ts"
10		},
11		"./utils": {
12			"jsr": "./src/utils.ts",
13			"import": "./dist/utils.js",
14			"types": "./dist/utils.d.ts"
15		}
16	},
17	"files": [
18		"dist",
19		"!dist/**/*.test.js"
20	],
21	"jsrInclude": [
22		"src"
23	],
24	"jsrExclude": [
25		"src/**/*.test.ts"
26	]
27}

Generated jsr.json:

1{
2	"name": "@ryoppippi/package",
3	"version": "1.0.0",
4	"exports": {
5		".": "./src/index.ts",
6		"./utils": "./src/utils.ts"
7	},
8	"publish": {
9		"include": ["dist", "src"],
10		"exclude": ["dist/**/*.test.js", "src/**/*.test.ts"]
11	}
12}

🔧 How it works

pkg-to-jsr performs the following steps:

1. 🔍 Locates your package.json file
2. 📤 Extracts relevant information such as name, version, and exports
3. ✍️ Generates a jsr.json file with the correct structure for JSR

More details on implementation can be found in the source code.

You can see example projects in the tests.

Name Handling

pkg-to-jsr determines the package name for jsr.json using the following logic:

1. 🏷️ If a jsrName field exists in package.json and is correctly formatted (@scope/package-name), it is used.
2. 📦 If jsrName is not present, it checks the name field in package.json. If this is correctly formatted for JSR, it is used.
3. 🔧 If name is not in JSR format, it combines the name and author fields. For example, if name is "package" and author is "ryoppippi", it generates @ryoppippi/package.
4. ❌ If none of the above methods produce a valid name, an error is thrown.

This approach allows maximum flexibility while ensuring compliance with JSR naming conventions.

Exports handling

The tool intelligently handles various exports configurations:

• 🧵 String exports are converted to object format
• 🧩 Complex exports with jsr, import, and other conditions are handled
• 🏆 If a jsr field is specified in the exports, it takes priority over other fields
• ⚠️ Invalid or unsupported exports are warned about and skipped

Publish configuration

pkg-to-jsr generates the publish.include and publish.exclude fields in jsr.json by merging and filtering information from multiple sources:

1. 📂 jsrInclude array in package.json: All entries are considered for inclusion
2. 🚫 jsrExclude array in package.json: All entries are considered for exclusion
3. 📁 files array in package.json:
   • Files without a leading ! are considered for inclusion
   • Files with a leading ! are considered for exclusion (with the ! removed)

The final include and exclude lists in jsr.json are the result of merging and filtering these sources:

• The include list combines unique entries from both jsrInclude and the positive entries in files, excluding any paths that are in jsrExclude
• The exclude list combines unique entries from both jsrExclude and the negative entries in files (with ! removed), excluding any paths that are in jsrInclude

This approach provides fine-grained control over what gets published to JSR while maintaining compatibility with existing files configurations and allowing for explicit inclusion and exclusion rules.

Example:

package.json:

1{
2	"files": [
3		"dist",
4		"src",
5		"!dist/**/*.test.js"
6	],
7	"jsrInclude": [
8		"src",
9		"types"
10	],
11	"jsrExclude": [
12		"src/**/*.test.ts",
13		"dist"
14	]
15}

Generated jsr.json:

1{
2	"publish": {
3		"include": ["src", "types"],
4		"exclude": ["dist/**/*.test.js", "src/**/*.test.ts"]
5	}
6}

In this example:

• src is included because it's in both files and jsrInclude
• types is included because it's in jsrInclude
• dist is excluded because it's in jsrExclude, overriding its presence in files
• Test files in both dist and src are excluded

This merged and filtered configuration ensures that all necessary files are included while respecting explicit inclusion and exclusion rules, providing precise control over the package contents for JSR publication.

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

📄 License

MIT