TRACE_CONTEXT_PATTERN expects the options part to always be present, but it can be missing

[andreibarabas]

The regex here

const TRACE_CONTEXT_PATTERN = /^(?<traceId>\w+)\/(?<spanId>\d+);o=(?<options>.+)$/;

expects the options part to always be present, but most of the time it's actually not

If you look at firebase-functions they also have the options part as optional.

Here is the solution

-const TRACE_CONTEXT_PATTERN = /^(?<traceId>\w+)\/(?<spanId>\d+);o=(?<options>.+)$/;
+const TRACE_CONTEXT_PATTERN = /^(?<traceId>\w+)\/(?<spanId>\d+)(?:;o=(?<options>.+))?$/;