A Snowpack plugin lets you extend Snowpack with new behaviors. Plugins can hook into different stages of the Snowpack build pipeline to add support for new file types and your favorite dev tools.

Prerequisites: Snowpack plugins are written in JavaScript and run via Node. Create a directory for your plugin called my-snowpack-plugin and inside it create a my-snowpack-plugin.

Bbuild test fraje new plugin, run npm init to ow a basic package. Build your own mtb frame plugin testing, create a new, example Snowpack project in a different directory. In your example Snowpack project, add your plugin to the snowpack. In your example Snowpack project, instead of enabling the plugin as a string containing the plugin name, use an array.

The first item is name of your plugin and the second a new object containing the plugin options. Snowpack uses an internal Build Pipeline to build frams in your application for development and production. Every source file passes through the build pipeline, which means that Snowpack can build more than just JavaScript.

Snowpack finds the first plugin that claims to resolve the given builf. Once loaded, every file passes through the build pipeline again to run through matching transform methods of all plugins that offer the method.

Plugins can build your own mtb frame plugin a file to modify its contents before finishing the file build. Snowpack plugins support a run method which lets you run any CLI tool and connect its output into Snowpack.

You can use this to run your favorite dev tools linters, TypeScript, etc. If the command fails, you can optionally fail your production build. Snowpack builds you a runnable, unbundled website by default, but you can kwn this final build with your favorite bundler webpack, Rollup, Parcel, etc.

When a bundler plugin fdame used, Snowpack will run the bundler on your build automatically to optimize it. A Snowpack plugin should be distributed as a function that can be called with plugin-specific options to return a plugin object. Snowpack will automatically call this function to load your plugin. That function accepts 2 parameters, in this order:. The object returned by plgin function is a Snowpack Plugin. A plugin consists of a name property and some hooks into the Snowpack lifecycle to customizes your build pipeline or dev environment.

In the example above we have:. This covers the basics of single-file transformations. When you build files from source, you also have the ability to transform the file type from source code to web code. The load method is responsible for loading and build files from disk while the resolve property tells Snowpack which files the plugin can load and what to expect as output.

In this build your own mtb frame plugin, the plugi claims responsibility for files matching any of the file extensions found in resolve. Because the. This build your own mtb frame plugin a simplified version of build your own mtb frame plugin official Snowpack Svelte plugin. In that case, the resolve property takes only a single input file type ['. Notice that.

Only the files returned by the load method are included in the final build. Plugins can produce server-optimized code for SSR via the load plugin hook. The isSSR flag tells the plugin that Snowpack is requesting your file for the server, and that it will expect a response that will run on the server.

Others like Svelte will create different output for the server than the browser. In the example below, we use the isSSR flag to tell the Svelte compiler to generate server-optimized code when requested by Snowpack.

Snowpack supports pluggable bundlers and other build optimizations via the optimize hook. This method runs after the build and gives plugins a chance to optimize the final build directory. Webpack, Rollup, and other build-only optimizations should use this hook. When the build command has finished building your application, this plugin hook is called with the buildDirectory path as an argument.

To share a plugin with the world, you can publish it to npm. For example, take a look at snowpack-plugin-starter-template which can get you up-and-running quickly. You can either copy this outright or simply take what you need. Snowpack 3. This guide takes you though creating and publishing your first plugin. Build Plugins Snowpack finds the first plugin that claims to resolve the given file. Transform Plugins Once loaded, every file passes through the build pipeline again to run through matching transform methods of all plugins that offer the method.

Bundler Plugins Snowpack builds you a runnable, unbundled website by default, but you can optimize this final build with your favorite bundler webpack, Rollup, Parcel, etc.

In the build your own mtb frame plugin above we have: The name property: The name of your plugin. This is usually the same as your package name if published to npm. Example: Build From Source When you build files from source, you also have the ability to transform the file type from source code to web code.

Be aware that npm install will remove your linked plugin, so on any install, build your own mtb frame plugin will need to redo the npm link my-snowpack-plugin. Snowpack will always keep the original file name App and only ever change the extension in the build. Extensions in Snowpack always have a leading. The resolve. But be sure to still return a plugin object.