Explicitly passing the context is robust but in my experience becomes neglected because of the extra work involved everywhere and so just doesn't happen. (The tracing equivalent of requiring a password so strong that people write it on sticky notes.)
My C++, Python, Ruby, C#, and Java runtimes provides thread local storage without cooperation from every function; I don't see why it's improper for my JS runtime to do the same.
Explicitly passing the context is robust but in my experience becomes neglected because of the extra work involved everywhere and so just doesn't happen. (The tracing equivalent of requiring a password so strong that people write it on sticky notes.)
My C++, Python, Ruby, C#, and Java runtimes provides thread local storage without cooperation from every function; I don't see why it's improper for my JS runtime to do the same.