Tiny Wasm Compiler

A WebAssembly compiler that fits in a tweet

via Simon Willison

This was a really cool walkthrough of an obfuscated program through incrementally deobfuscating it. I especially liked the heavy use of coercion in the obfuscated code, since that heavily leans on JavaScript’s somewhat janky typecasting that always leads to interesting results. I’ve previously written a compiler using LLVM, and the similar “low-level but not too low-level” aspect of the Wasm byte array makes it seem like a fun spec to create and compile a language into.