#breakdown Bun is a new 'all-in-one' Javascript runtime. This means that it contains a runtime, bundler, transpiler, test runner, and package manager in a single tool.
Recently it introduced 'macros', a way of running [[js]] functions at bundle-time. These values are then directly inlined into the bundle. These can be super useful for one-off build scripts, setting variables, making fetch requests at bundle-time, etc.