## Publishing Packages

Publishing a Meteor package involves a few key steps, including setting up your package, testing it, and finally publishing it to the Meteor package repository. Here's a brief guide on how to publish Meteor packages using Meteor 3, specifically with the `meteor publish --release=3.0-rc.2` command.

### Prerequisites
- Ensure you have Meteor 3 installed. You can check your Meteor version and automatically download it if it's missing:
  ```bash
  meteor --version --release=3.0-rc.2
  ```
- Have a Meteor developer account. You can create one at [Meteor's official website](https://www.meteor.com/).

### Step-by-Step Guide

#### 1. Set Up Your Package
First, you need to create a package directory and set up your package structure.


1. **Create the package structure:**

```bash
meteor create --package user:package
cd package
```

2. **Edit the `package.js` file:**
This file contains metadata about your package and its dependencies. Here's an example structure:

```javascript
Package.describe({
 name: 'user:package',
 version: '0.0.1',
 summary: 'A brief description of my package',
 git: 'https://github.com/myusername/my-package',
 documentation: 'README.md'
});

Package.onUse(function(api) {
 api.versionsFrom('3.0-rc.2');
 api.use('ecmascript');
 api.mainModule('my-package.js');
});

Package.onTest(function(api) {
 api.use('ecmascript');
 api.use('tinytest');
 api.use('user:package');
 api.mainModule('my-package-tests.js');
});
```

If the package is also intended to work with Meteor 2 you can use:

```javascript
api.versionsFrom(['2.3', '3.0-rc.2']);
```

3. **Create the main module file:**
```bash
touch my-package.js
```

4. **Create a test file (optional but recommended):**
```bash
touch my-package-tests.js
```

#### 2. Develop Your Package
Add your package logic in `my-package.js`. For example:

```javascript
export const greet = (name) => {
  return `Hello, ${name}!`;
};
```

#### 3. Test Your Package
Before publishing, ensure your package works as expected.

1. **Run tests:**
```bash
meteor test-packages ./ --driver-package meteortesting:mocha
```

2. **Fix any issues** encountered during testing.

#### 4. Publish Your Package
Once your package is ready and tested, you can publish it using the following command:

```bash
meteor publish --release=3.0-rc.2
```

You can replace `3.0-rc.2` with the appropriate release version. If you omit the `--release` flag, it will default to the latest official Meteor version, which at the time of this writing is Meteor 2. That way packages published without specifying a release will not be compatible with Meteor 3, as there will probably be a `fibers` related error.

- **Login if prompted:**
  You will be asked to log in with your Meteor developer account credentials if you aren't already logged in.

- **Publish confirmation:**
  After logging in, your package will be published to the Meteor package repository.

#### 5. Verify Your Package
To ensure your package has been published correctly, you can search for it in the Meteor package repository or try to add it to a Meteor project:

```bash
meteor add user:package
```

### Tips
- **Versioning:** Follow semantic versioning for your package versions to ensure compatibility and proper version management.
- **Documentation:** Provide thorough documentation in the `README.md` file to help users understand how to use your package.
- **Git Repository:** Keep your package source code in a version-controlled repository like GitHub for easy collaboration and updates.

By following these steps, you should be able to publish your Meteor packages with Meteor 3 successfully. Happy coding!