Bun v0.0.26

## Features ### Bun Macro Bun Macros are a simple way to move code snippets from runtime to build-time. Use them for: - Zero runtime CSS-in-JS (or a little runtime, up to you) - GraphQL parsing - Static data fetching without a library (similar to Next.js' `getStaticProps` but from any file instead of just pages) - you can come up with more use cases This API (and implementation) is very new and I want to hear feedback on what to change. How to use macros: - Any import that starts with `macro:` is imported as a macro. Macros can be npm packages, local files, or anything else resolvable. These imports are always removed from the final output. - Imports must be a named import, and are matched against call expressions (function calls) and template literals. JSX props may be added in a future release Here's a quick example of using a macro: ```tsx // This import won't exist at runtime! import { matchInFile } from "macro:./matchInFile"; export const IPAddresses = () => ( <div> <h2>recent ip addresses</h2> <div className="Lines"> {/* matchInFile gets inlined into an array at compile time */} {matchInFile("access.log", /^(?:[0-9]{1,3}\.){3}[0-9]{1,3}/).map( (ipAddress, index) => ( <div className="Line" key={index}> {ipAddress} </div> ) )} </div> </div> ); ``` The transpiled output looks something like this: ```js export const IPAddresses = () => jsx("div", { children: [ jsx("h2", { children: ["recent ip addresses"] }, undefined, true, {}, this), jsx("div", { className: "Lines", children: [[ "98.210.28.6", "192.99.4.168", // ... rest of the array ].map((ipAddress, index) => jsx("div", { className: "Line", children: [ipAddress] }, index, true, {}, this))] }, undefined, true, {}, this) // ...rest of code ] }); ``` There are a few examples of how to write macros in https://github.com/Jarred-Sumner/bun/tree/main/examples/macros, but I will write more docs once I'm a little more confident that the API isn't going to change. Once I write macros for Relay and Emotion, I'll have a better sense for if this API is good enough or if there are changes to make. I might change the import prefix from `macro:` to `bun:` because it's shorter and slightly faster to check (one u32 instead of a u32 and then a u16) #### Credits Bun Macros are inspired by [babel-plugin-macros](https://github.com/kentcdodds/babel-plugin-macros), which was [Sunil Pai's idea](https://twitter.com/threepointone/status/885884698093899777). They're also sort of similar to Zig's `comptime` feature. ### Bun.js - `Bun.readFileAsBytes` and `Bun.readFile` now accept an array of paths to join. Both of these are valid: Option A: ```js Bun.readFile(Bun.cwd + "file.txt"); ``` Option B: ```js Bun.readFile([Bun.cwd, "./text/", "file.txt"]); ``` Unlike Node.js' `path.join`, it's an explicit array instead of arguments because someday, we might want to add extra options to this function. ## Bug fixes - Thanks @alexkuz for adding a check to the Makefile that necessary dependencies are installed prior to compiling Bun. - Fixed an occasional UTF-8 decoding bug in `Response.text()` (from `fetch`) - Fixed an edgecase in the URL parser where it would sometimes erroneously report the pathname as `/` - Fixed a typo in the error thrown when you pass a blank string to `fetch` - `fetch` now includes a `User-Agent` header by default. This is overridable, but it defaults to `Bun.js v0.0.version-number`