According to Android OS Documentation:
The Android framework has a small tool called validatekeymaps to validate the syntax of input device configuration files, key layout files, key character maps files and virtual key definition files.
This projects contains a subset of Android Open Source Project source code so you can easily build validatekeymaps without checking out AOSP sources and installing specific build tools.
Additionaly there is a code to compile JS/WASM version of validatekeymaps using Emscripten. The resulting Web version of validatekeymaps is available here.